core | hofkit

Index

Array Functions

Boolean Functions

isBoolean

Function Functions

Logic Functions

Number Functions

Object Functions

Other Functions

toggleStrings

Promise Functions

String Functions

Array Functions

Const all

all<T>(predicate: (value: T, index: number) => boolean): (array: T[]) => boolean

Finally returns true if predicate returns true for all elements in array, else returns false.
memberof

core

since

0.1.0

see

any

example
```
all(v => v > 0)([]) //=> true
all(v => v > 0)([1, 2, 3]) //=> true
all(v => v > 0)([-1, 2, 3]) //=> false
all(v => v as number > 0)([-1, '1']) //=> true
```
Type parameters
- T
Parameters
- predicate: (value: T, index: number) => boolean
  
  Returns true to indicate value passes evaluation, else returns false.
  - - (value: T, index: number): boolean
    - Parameters
      - value: T
      - index: number
      Returns boolean
Returns (array: T[]) => boolean

Finally returns true if predicate returns true for all elements in array, else returns false.
- - (array: T[]): boolean
  - Parameters
    - array: T[]
      
      Array to test.
    Returns boolean

Const allFalse

allFalse(array: any[]): boolean

Returns true if all elements in array are false, else returns false.
memberof

core

since

0.1.0

see

all allTrue

example
```
allFalse([]) //=> true
allFalse([true]) //=> false
allFalse([false]) //=> true
allFalse([true, false]) //=> false
```
Parameters
- array: any[]
  
  Array to test.
Returns boolean

true if all elements in array are false, else returns false

Const allNotNil

allNotNil(array: any[]): boolean

Returns true if all elements in array are not null or undefined, else returns false.
memberof

core

since

0.1.0

see

all

example
```
allNotNil([]) //=> true
allNotNil([1]) //=> true
allNotNil([1, 2]) //=> true
allNotNil([1, 'a']) //=> true
allNotNil([1, null]) //=> false
allNotNil([1, undefined]) //=> false
```
Parameters
- array: any[]
  
  Array to test.
Returns boolean

true if all elements in array are not null or undefined, else returns false.

Const allTrue

allTrue(array: any[]): boolean

Returns true if all elements in array are true, else returns false.
memberof

core

since

0.1.0

see

all allFalse

example
```
allTrue([]) //=> true
allTrue([true]) //=> true
allTrue([false]) //=> false
allTrue([true, false]) //=> false
```
Parameters
- array: any[]
  
  Array to test.
Returns boolean

true if all elements in array are true, else returns false.

Const any

any<T>(predicate: (value: T, index: number) => boolean): (array: T[]) => boolean

Finally returns true if predicate returns true for at least 1 element in array, else returns false.
memberof

core

since

0.1.0

see

all anyFalse anyNil anyTrue

example
```
any(v => v > 0)([]) //=> false
any(v => v > 0)([-1, -2, 3]) //=> true
any(v => v > 0)([-1, -2, -3]) //=> false
any(v => v as number > 0)([1, 'a']) //=> true
```
Type parameters
- T
Parameters
- predicate: (value: T, index: number) => boolean
  
  Returns true to indicate value passes evaluation, else returns false.
  - - (value: T, index: number): boolean
    - Parameters
      - value: T
      - index: number
      Returns boolean
Returns (array: T[]) => boolean

Finally returns true if predicate returns true for at least 1 element in array, else returns false.
- - (array: T[]): boolean
  - Parameters
    - array: T[]
      
      Array to test.
    Returns boolean

Const anyFalse

anyFalse(array: any[]): boolean

Returns true if at least 1 element in array is false, else returns false.
memberof

core

since

0.1.0

see

any anyTrue

example
```
anyFalse([]) //=> false
anyFalse([true, false]) //=> true
anyFalse([true, true]) //=> false
```
Parameters
- array: any[]
  
  Array to test.
Returns boolean

true if at least 1 element in array is false, else returns false.

Const anyNil

anyNil(array: any[]): boolean

Returns true if all elements in array are true, else returns false.
memberof

core

since

0.1.0

see

any

example
```
anyNil([]) //=> false
anyNil([1, 2]) //=> false
anyNil([1, null]) //=> true
anyNil([1, undefined]) //=> true
```
Parameters
- array: any[]
  
  Array to test.
Returns boolean

true if all elements in array are true, else returns false.

Const anyTrue

anyTrue(array: any[]): boolean

Returns true if at least 1 element in array is true, else returns false.
memberof

core

since

0.1.0

see

any anyFalse

example
```
anyTrue([]) //=> false
anyTrue([true, false]) //=> true
anyTrue([false, false]) //=> false
```
Parameters
- array: any[]
  
  Array to test.
Returns boolean

true if at least 1 element in array is true, else returns false.

Const arrayIf

arrayIf<T>(predicate: (array: T[]) => boolean, defaultArray?: T[]): (array: T[]) => T[]

Finally returns array if predicate returns true, else returns defaultArray (optional, defaults to empty array).
memberof

core

since

0.1.0

see

valueIf

example
```
arrayIf(array => array.includes(4), [1])([1, 2, 3]); //=> [1]
arrayIf(array => array.includes(2), [1])([1, 2, 3]); //=> [1, 2, 3]
```
Type parameters
- T
Parameters
- predicate: (array: T[]) => boolean
  
  Boolean function to determine which array to return.
  - - (array: T[]): boolean
    - Parameters
      - array: T[]
      Returns boolean
- defaultArray: T[] = []
  
  The default array to return.
Returns (array: T[]) => T[]

Finally returns array if predicate returns true, else returns defaultArray.
- - (array: T[]): T[]
  - Parameters
    - array: T[]
    Returns T[]

Const arrayOr

arrayOr<T>(defaultArray?: T[]): (array: any) => T[]

Finally returns array if it is valid via isArray, else returns defaultArray.
memberof

core

since

0.1.0

see

valueIf arrayIf

example
```
arrayOr()(null); //=> [] as unknown[]
arrayOr([1])(null); //=> [1]
arrayOr([1])([1, 2, 3]); //=> [1, 2, 3]
```
Type parameters
- T
Parameters
- defaultArray: T[] = []
  
  Default array to return.
Returns (array: any) => T[]

Finally returns array if it is valid via isArray, else returns defaultArray.
- - (array: any): T[]
  - Parameters
    - array: any
      
      Array to test.
    Returns T[]

Const atIndex

atIndex(index: number): <T>(array: T[]) => T

Finally returns the element at index if found in array, else returns undefined.
memberof

core

since

0.1.0

example
```
 atIndex(0)([]); //=> undefined
 atIndex(0)([1, 2, 3]); //=> 1
 atIndex(1)([1, 2, 3]); //=> 2
 atIndex(0)([1, 'a', 2]); //=> 1
```
Parameters
- index: number
 
 Index of element in array to return.
Returns <T>(array: T[]) => T

Finally returns the element at index if found in array, else returns undefined.
- - <T>(array: T[]): T
 - Type parameters
 - T
 Parameters
 - array: T[]
 
 Array to get an element from.
 Returns T

Const atRandom

atRandom<T>(array: T[]): undefined | T

Returns undefined if array has no elements, else returns a random element from array.
memberof

core

since

0.1.0

see

atIndex

example
```
 atRandom([]); //=> undefined
 atRandom([1, 2, 3]); //=> v where [1, 2, 3].includes(v)
 atRandom([1, 'a', 2]); //=> v where [1, 2, 3].includes(v)
```
Type parameters
- T
Parameters
- array: T[]
  
  Array to get an element from.
Returns undefined | T

Returns undefined if array has no elements, else returns a random element from array.

Const coalesce

coalesce<T>(array: T[]): undefined | T

Returns the first non-null, non-undefined element in array, else returns undefined.
memberof

core

since

0.1.0

see

compact

example
```
 coalesce([]); //=> undefined
 coalesce([null, undefined, 1]); //=> 1
```
Type parameters
- T
Parameters
- array: T[]
  
  Array to use.
Returns undefined | T

The first non-null, non-undefined element in array, else returns undefined.

Const compact

compact<T>(array: T[]): T[]

Returns an array containing only truthy values from array.
memberof

core

since

0.1.0

see

coalesce

example
```
compact([]); //=> []
compact([null, undefined, [], '', 'a', 0, 1, 0.1, true, false, {}, { a: 1 }]); //=> [[], 'a', 1, 0.1, true, {}, { a: 1 }]
```
Type parameters
- T
Parameters
- array: T[]
  
  Array to use.
Returns T[]

Returns an array containing only truthy values from array.

Const concat

concat<T>(array1: T[]): (array2: U[]) => (T | U)[]

Finally returns an array containing all elements in array1 and array2 (includes duplicates).
memberof

core

since

0.1.0

see

union

example
```
concat([])([]); //=> []
concat([1, 2])([3, 4]); //=> [1, 2, 3, 4]
concat([1, 'a'])(['b', 2]); //=> [1, 'a', 'b', 2]
```
Type parameters
- T
Parameters
- array1: T[]
 
 Array to add elements to.
Returns (array2: U[]) => (T | U)[]

Finally returns an array containing all elements in array1 and array2 (includes duplicates).
- - (array2: U[]): (T | U)[]
 - Type parameters
 - U
 Parameters
 - array2: U[]
 
 Array to add elements from.
 Returns (T | U)[]

Const count

count<T>(array: T[]): number

Returns the number of elements in array.
memberof

core

since

0.1.0

see

countIs countIsAny countIsNone

example
```
count([]); //=> 0
count([1, 2, 3]); //=> 3
```
Type parameters
- T
Parameters
- array: T[]
  
  The array to count.
Returns number

Returns the number of elements in array.

Const countIs

countIs(count: number): <T>(array: T[]) => boolean

Finally returns true if array's count is equal to count, else returns false.
memberof

core

since

0.1.0

see

count countIsAny countIsNone

example
```
count(0)([]); //=> true
count(3)([1, 2, 3]); //=> true
count(4)([1, 2, 3]); //=> false
```
Parameters
- count: number
 
 The expected count.
Returns <T>(array: T[]) => boolean

Finally returns true if array's count is equal to count, else returns false.
- - <T>(array: T[]): boolean
 - Type parameters
 - T
 Parameters
 - array: T[]
 Returns boolean

Const countIsAny

countIsAny<T>(array: T[]): boolean

Returns true if array's count is greater than 0, else returns false.
memberof

core

since

0.1.0

see
count countIsNone
```
count([]); //=> false
count([1, 2, 3]); //=> true
```
Type parameters
- T
Parameters
- array: T[]
  
  Array to test.
Returns boolean

true if array's count is greater than 0, else returns false.

Const countIsNone

countIsNone<T>(array: T[]): boolean

Returns true if array's count is equal to 0, else returns false.
memberof

core

since

0.1.0

see
count countIsAny
```
count([]); //=> true
count([1, 2, 3]); //=> false
```
Type parameters
- T
Parameters
- array: T[]
  
  Array to test.
Returns boolean

true if array's count is equal to 0, else returns false.

Const difference

difference(array1: any[]): (array2: any[]) => any[]

Finally returns all elements in array2 that are not present in array1 (i.e., returns the difference of array2 - array1).
memberof

core

since

0.1.0

see

intersection

example
```
difference([])([]) //=> []
difference([])([1, 2, 3]) //=> [1, 2, 3]
difference([1])([1]) //=> []
difference([1])([1, 2]) //=> [2]
difference([1])([3, 4]) //=> [3, 4]
difference([1, 'a'])([1, 'b']) //=> ['b']
```
Parameters
- array1: any[]
  
  Array to subtract.
Returns (array2: any[]) => any[]

Finally returns all elements in array2 that are not present in array1
- - (array2: any[]): any[]
  - Parameters
    - array2: any[]
      
      Array to subtract from.
    Returns any[]

Const excludes

excludes(...elements: any[]): <T>(array: T[]) => boolean

Inverse of includes. I.e., returns true if array does not include all elements, else returns false.
memberof

core

since

0.1.0

see

includes

example
```
excludes()([]) //=> true
excludes()([1, 2, 3]) //=> true
excludes(4)([1, 2, 3]) //=> true
excludes(1)([1, 2, 3]) //=> false
excludes(1, 2)([1, 2, 3]) //=> false
```
Parameters
- Rest ...elements: any[]
 
 Array of elements to check are excluded.
Returns <T>(array: T[]) => boolean

true if array does not include all elements, else returns false.
- - <T>(array: T[]): boolean
 - Type parameters
 - T
 Parameters
 - array: T[]
 
 Array to test.
 Returns boolean

Const fill

fill<TFiller, TArray>(filler: TFiller, options?: FillOptions): (array: TArray[]) => (TFiller | TArray)[]

Finally returns array filled with a filler value starting from FillOptions.start to FillOptions.end.
example
```
fill('a', { start: 1, end: 2 })([1, 2, 3, 4]); //=> [1, 'a', 'a', 4]
```
If FillOptions.end exceeds array.length then array's length will be increased to equal FillOptions.end before filling.
example
```
// Note the array's length is less than `end` hence the array is extended to
// match `end` before filling.
fill('a', { end: 3 })([]); //=> ['a', 'a', 'a']
```
memberof

core

since

0.1.0

see

fillRecursive
Type parameters
- TFiller
- TArray
Parameters
- filler: TFiller
  
  Value to fill array with.
- options: FillOptions = {}
Returns (array: TArray[]) => (TFiller | TArray)[]

Finally returns array filled with a filler value starting from FillOptions.start to FillOptions.end.
- - (array: TArray[]): (TFiller | TArray)[]
  - Parameters
    - array: TArray[]
    Returns (TFiller | TArray)[]

Const fillRecursive

fillRecursive<TFiller, TArray>(transformer: (prev: TFiller | TArray) => TFiller, total: number): (array: (TFiller | TArray)[]) => (TFiller | TArray)[]

Finally returns array filled recursively where a total number subsequent elements are provided by a transformer that receives the previous element.
memberof

core

since

0.1.0

example
```
fillRecursive(prev => prev * 2, 4)([]); //=> []
fillRecursive(prev => prev * 2, 4)([1]); //=> [1, 2, 4, 8, 16]
fillRecursive(prev => prev * 2, 4)([1, 2]); //=> [1, 2, 4, 8, 16, 32]
```
Type parameters
- TFiller
- TArray
Parameters
- transformer: (prev: TFiller | TArray) => TFiller
  
  Returns a new value for prev.
  - - (prev: TFiller | TArray): TFiller
    - Parameters
      - prev: TFiller | TArray
      Returns TFiller
- total: number
  
  Number of elements to fill array with.
Returns (array: (TFiller | TArray)[]) => (TFiller | TArray)[]

Finally returns array filled recursively with elements provided by transformer.
- - (array: (TFiller | TArray)[]): (TFiller | TArray)[]
  - Parameters
    - array: (TFiller | TArray)[]
    Returns (TFiller | TArray)[]

Const filter

filter<T>(predicate: (value: T, index: number) => boolean): (array: T[]) => T[]

Finally returns array elements where predicate returns true.
memberof

core

since

0.1.0

see

filterEntries filterNot filterMap filterPart includes excludes

example
```
filter((v) => v > 0)([]) //=> []
filter((v) => v > 0)([-1, 2, 3]) //=> [2, 3]
filter((v) => v as number > 0)([1, '2', -3]) //=> [1, '2']
```
Type parameters
- T
Parameters
- predicate: (value: T, index: number) => boolean
  
  Returns true to keep value, else returns false to omit value.
  - - (value: T, index: number): boolean
    - Parameters
      - value: T
      - index: number
      Returns boolean
Returns (array: T[]) => T[]

Finally returns array elements where predicate returns true.
- - (array: T[]): T[]
  - Parameters
    - array: T[]
      
      Array to filter.
    Returns T[]

Const filterMap

filterMap<TArray, TMapped>(transformer: (value: TArray, index: number) => TArray | TMapped, options?: FilterMapOptions<TArray, TMapped>): (array: TArray[]) => (TArray | TMapped)[]

Returns a filtered & transformed array by sequentially applying filter, map, and filter to each element in 1 iteration to improve performance rather than manually chaining these operations (which would result in several iterations).

I.e., keeps array elements where FilterMapOptions.preFilter (optional, defaults to return true) is true, then uses transformer to return new elements, and finally keeps elements where FilterMapOptions.postFilter (optional, defaults to return true) is true.

Note: Filters will affect the provided index for transformer, e.g., if 'a' is preFiltered from ['a', 'b'] then transformer receives index 0 for b.
memberof

core

since

0.1.0

see

filter map

example
```
// Pre- and post- filter:
const noAPredicate = (v: string) => !v.includes('a');
const noCPredicate = (v: string) => !v.includes('c');
const appendDTransformer = (v: string) => v + 'd';
filterMap(appendDTransformer, { preFilter: noAPredicate, postFilter: noCPredicate })([]) //=> []
filterMap(appendDTransformer, { preFilter: noAPredicate, postFilter: noCPredicate })(['a', 'b', 'c']) //=> ['bd']

// Pre-filter:
const positivePredicate = (v: number) => v > 0;
const incrementTransformer = (v: number) => v + 1;
filterMap(incrementTransformer, { preFilter: positivePredicate })([-1, 2, 3]) //=> [3, 4]
// Post-filter:
filterMap(incrementTransformer, { postFilter: positivePredicate }) //=> [3, 4]
```
Type parameters
- TArray
- TMapped
Parameters
- transformer: (value: TArray, index: number) => TArray | TMapped
 
 Applied after options.preFilter (if value is kept) and before options.postFilter, returns a new value, see map.
 - - (value: TArray, index: number): TArray | TMapped
 - Parameters
 - value: TArray
 - index: number
 Returns TArray | TMapped
- options: FilterMapOptions<TArray, TMapped> = {}
Returns (array: TArray[]) => (TArray | TMapped)[]

Finally returns array after applying a pre-filter, transformation, & post-filter.
- - (array: TArray[]): (TArray | TMapped)[]
 - Parameters
 - array: TArray[]
 Returns (TArray | TMapped)[]

Const filterNot

filterNot<T>(predicate: (value: T, index: number) => boolean): (array: T[]) => T[]

Inverse of filter, i.e., finally returns array with elements where predicate returns false.
memberof

core

since

0.1.0

see

excludes filter negate

example
```
filterNot((v) => v > 0)([]) //=> []
filterNot((v) => v > 0)([-1, 2, 3]) //=> [-1]
filterNot((v) => v as number > 0)([1, '2', -3]) //=> [-3]
```
Type parameters
- T
Parameters
- predicate: (value: T, index: number) => boolean
  
  Returns false to keep value, else returns true to omit value.
  - - (value: T, index: number): boolean
    - Parameters
      - value: T
      - index: number
      Returns boolean
Returns (array: T[]) => T[]

Finally returns array with elements where predicate returns false.
- - (array: T[]): T[]
  - Parameters
    - array: T[]
      
      Array to filter.
    Returns T[]

Const filterPart

filterPart<T>(predicate: (value: T, index: number) => boolean): (array: T[]) => T[][]

Combines filter & filterNot to finally return a 2D array where the first array contains the kept elements whilst the second array contains the remaining elements (that are usually omitted in filter).
memberof

core

since

0.1.0

see

filter filterNot takePart

example
```
const isEven = n => n % 2 === 0;
filterPart(isEven)([]) //=> [[], []]
filterPart(isEven)([1, 2, 3, 4]) //=> [[2, 4], [1, 3]]
filterPart(isEven)([1, '2', 3, 4]) //=> [['2', 4], [1, 3]
```
Type parameters
- T
Parameters
- predicate: (value: T, index: number) => boolean
  
  Returns true to keep value, else returns false to omit value.
  - - (value: T, index: number): boolean
    - Parameters
      - value: T
      - index: number
      Returns boolean
Returns (array: T[]) => T[][]

Finally returns an array containing 2 arrays of the form [...kept, ...omitted].
- - (array: T[]): T[][]
  - Parameters
    - array: T[]
      
      Array to filter.
    Returns T[][]

Const findOr

findOr<T, U>(defaultValue: U, predicate: (value: T, index: number) => boolean): (array: T[]) => T | U

Finally returns the element where predicate is true, else returns defaultValue.
memberof

core

since

0.1.0

example
```
findOr(4, (v: number) => v > 0)([]) //=> 4
findOr(4, (v: number) => v > 0)([-1, -2, 3]) //=> 3
findOr(4, (v) => v > 0)([-1, -2, -3]) //=> 4
findOr(4, (v) => v as number > 0)([-1, 'a', -3]) //=> 4
```
Type parameters
- T
- U
Parameters
- defaultValue: U
  
  Value to return when predicate returns false.
- predicate: (value: T, index: number) => boolean
  
  Returns true to indicate the value passes evaluation (i.e., matches the search), else returns false to indicate value fails evaluation.
  - - (value: T, index: number): boolean
    - Parameters
      - value: T
      - index: number
      Returns boolean
Returns (array: T[]) => T | U

Finally returns the element where predicate is true, else returns defaultValue.
- - (array: T[]): T | U
  - Parameters
    - array: T[]
    Returns T | U

Const groupBy

groupBy<TItem, TItemTransformed, TAggregate>(keySelector: (item: TItem) => string, options?: GroupByOptions<TItem, TItemTransformed, TAggregate>): (items: TItem[]) => Record<string, TItem[]> | Record<string, TItemTransformed[]> | Record<string, TAggregate>

Restricts a given value to be inclusively within the range of min to max.
memberof

core

since

1.0.0

example
```
interface Pet { name: string; age: number };
const pets: Pet[] = [{ name: 'pet1', age: 1 }, { name: 'pet2', age: 2 }, { name: 'pet3', age: 2 }];
const byAge = (p: Pet) => p.age;
// Group `pets` by their `name`.
groupBy(byAge)(pets); //=> {1: [{ name: 'pet1', age: 1 }], 2: [ { name: 'pet2', age: 2 }, { name: 'pet3', age: 2 }]}
const withName = (p: Pet) => p.name;
// Group `pets` by `name` & map items to their name
groupBy(byAge, { itemTransformer: withName)(pets); //=> {1: ['pet1'], 2: ['pet2', 'pet3']}
const sumAges = (ageGroup: string, ages) => sum(ages as number[]);
// Group `pets` by `name` & map groups to a summed value.
groupBy(byAge, { aggregateTransformer: sumAges)(pets); //=> {1: 1, 2: 4}
```
Type parameters
- TItem
- TItemTransformed
- TAggregate
Parameters
- keySelector: (item: TItem) => string
 
 Item key to group by.
 - - (item: TItem): string
 - Parameters
 - item: TItem
 Returns string
- Optional options: GroupByOptions<TItem, TItemTransformed, TAggregate>
Returns (items: TItem[]) => Record<string, TItem[]> | Record<string, TItemTransformed[]> | Record<string, TAggregate>

Finally returns an object mapping keys to either a group of items (via itemTransformer) or an aggregate value (via aggregateTransformer).
- - (items: TItem[]): Record<string, TItem[]> | Record<string, TItemTransformed[]> | Record<string, TAggregate>
 - Parameters
 - items: TItem[]
 Returns Record<string, TItem[]> | Record<string, TItemTransformed[]> | Record<string, TAggregate>

Const head

head<T>(array: T[]): T

Returns the first element of array if found else returns undefined.
memberof

core

since

0.1.0

alias

first

see

init atIndex last tail

example
```
 head([]); //=> undefined
 head([1, 2, 3]); //=> 1
```
Type parameters
- T
Parameters
- array: T[]
  
  Array to use.
Returns T

The first element of array if found else returns undefined.

Const includes

includes(...elements: any[]): <T>(array: T[]) => boolean

Finally returns true if array includes all elements, else returns false.
memberof

core

since

0.1.0

see

excludes filter

example
```
includes()([]) //=> false
includes()([1, 2, 3]) //=> false
includes(4)([1, 2, 3]) //=> false
includes(1)([1, 2, 3]) //=> true
includes(1, 2)([1, 2, 3]) //=> true
```
Parameters
- Rest ...elements: any[]
 
 The elements to check for.
Returns <T>(array: T[]) => boolean

Finally returns true if array includes all elements, else returns false.
- - <T>(array: T[]): boolean
 - Type parameters
 - T
 Parameters
 - array: T[]
 
 Array to test.
 Returns boolean

Const indexOf

indexOf(element: any): <T>(array: T[]) => number

Finally returns the index of element if found in array, else returns -1.
memberof

core

since

0.1.0

example
```
 indexOf()([]); //=> -1
 indexOf(1)([]); //=> -1
 indexOf(1)([1]); //=> 0
 indexOf(2)([1, 2]); //=> 1
```
Parameters
- element: any
 
 Element to search for.
Returns <T>(array: T[]) => number

Index of element if found in array, else returns -1.
- - <T>(array: T[]): number
 - Type parameters
 - T
 Parameters
 - array: T[]
 
 Array to search in.
 Returns number

Const init

init<T>(array: T[]): T[]

Returns array without the last element.
memberof

core

since

0.1.0

see

head last tail

example
```
 init([]); //=> []
 init([1, 2, 3]); //=> [1, 2]
 init([1, 'a', true]); //=> [1, 'a']
```
Type parameters
- T
Parameters
- array: T[]
  
  Array to use.
Returns T[]

Returns array without the last element.

Const intersection

intersection(array1: any[]): (array2: any[]) => any[]

Finally returns elements present in both array1 and array2.
memberof

core

since

0.1.0

example
```
intersection([])([]) //=> []
intersection([])([1, 2, 3]) //=> []
intersection([1])([1]) //=> [1]
intersection([1, 2])([1, 2]) //=> [1, 2]
intersection([1, 2])([3, 4]) //=> []
intersection([1, 'a'])([1, 'b']) //=> [1]
```
Parameters
- array1: any[]
  
  Second array to test.
Returns (array2: any[]) => any[]

Finally returns elements present in both array1 and array2.
- - (array2: any[]): any[]
  - Parameters
    - array2: any[]
    Returns any[]

Const isArray

isArray(value: any): boolean

Returns true if value is an array, else returns false.
memberof

core

since

0.1.0

see

isObject

example
```
isArray(null); //=> false
isArray([]); //=> true
isArray([1, 2, 3]); //=> true
```
Parameters
- value: any
  
  Value to test.
Returns boolean

true if value is an array, else returns false

Const join

join(delimiter?: string): <T>(value: T[]) => string

Inverse of split, i.e., Finally returns a string containing elements from array delimited by delimiter (optional, defaults to ,)
memberof

core

since

0.1.0

see

split

example
```
join('')([]); //=> []
join()(['foo', 'bar', 'baz']); //=> 'foo bar baz'
join(' ')(['foo', 'bar', 'baz']); //=> 'foo bar baz'
join('')(['f', 'o', 'o']); //=> 'foo'
```
Parameters
- delimiter: string = ','
Returns <T>(value: T[]) => string

Finally returns a string elements from array that are delimited by delimiter.
- - <T>(value: T[]): string
 - Type parameters
 - T
 Parameters
 - value: T[]
 Returns string

Const keyBy

keyBy<T>(selector: (element: T) => string): (array: T[]) => Record<string, T>

Uses selector to generate a string key from array elements, then finally returns a Record containing entries where each element becomes the value to the key it provided.

Elements that provide an invalid key (e.g., undefined) are omitted.
memberof

core

since

0.1.0

example
```
 keyBy(v => v.name)([]); //=> {}
 keyBy(v => v.name)([{ name: 'a', orders: 1 }, , { name: 'b' }]); //=> { a: { name: 'a', orders: 1 }, b: { name: 'b' } }
 keyBy(v => v.orders)([{ name: 'a', orders: 1 }, , { name: 'b' }]); //=> { a: { name: 'a', orders: 1 } }
```
Type parameters
- T: Record<string, any>
Parameters
- selector: (element: T) => string
 
 Returns a key for element that will form an entry in the returned object.
 - - (element: T): string
 - Parameters
 - element: T
 Returns string
Returns (array: T[]) => Record<string, T>

Finally returns a Record containing entries where each element becomes the value to the key it provided.
- - (array: T[]): Record<string, T>
 - Parameters
 - array: T[]
 Returns Record<string, T>

Const last

last<T>(array: T[]): T

Returns the last element of array if it exists else returns undefined.
memberof

core

since

0.1.0

example
```
 last([]); //=> undefined
 last([1, 2, 3]); //=> 3
```
Type parameters
- T
Parameters
- array: T[]
  
  Array to use.
Returns T

The last element of array if it exists else returns undefined.

Const map

map<T, U>(transformer: (value: T, index: number) => U): (array: T[]) => U[]

Finally returns array containing elements mapped using transformer to provide the new value.
memberof

core

since

0.1.0

example
```
map((v) => v * 2)([]) //=> []
map((v) => v * 2)([1, 2, 3]) //=> [2, 4, 6]
map((v) => v * 2)([1, '2']) //=> [2, 4]
```
Type parameters
- T
- U
Parameters
- transformer: (value: T, index: number) => U
  
  Returns a new value.
  - - (value: T, index: number): U
    - Parameters
      - value: T
      - index: number
      Returns U
Returns (array: T[]) => U[]

Finally returns array containing elements mapped using transformer to provide the new value.
- - (array: T[]): U[]
  - Parameters
    - array: T[]
      
      Array to map.
    Returns U[]

Const prepend

prepend(element: any): <T>(array: T[]) => any[]

Finally returns array with element prepended.
memberof

core

since

0.1.0

alias

queue

alias

unshift

see

push

example
```
prepend(1)([]); //=> [1]
prepend(4)([1, 2, 3]); //=> [4, 1, 2, 3]
```
Parameters
- element: any
 
 Element to prepend.
Returns <T>(array: T[]) => any[]
- - <T>(array: T[]): any[]
 - Type parameters
 - T
 Parameters
 - array: T[]
 
 Array to prepend to.
 Returns any[]

Const push

push(element: any): <T>(array: T[]) => any[]

Finally returns array with element appended.
memberof

core

since

0.1.0

alias

append

see

prepend

example
```
push(1)([]); //=> [1]
push(4)([1, 2, 3]); //=> [1, 2, 3, 4]
```
Parameters
- element: any
 
 Element to append.
Returns <T>(array: T[]) => any[]
- - <T>(array: T[]): any[]
 - Type parameters
 - T
 Parameters
 - array: T[]
 
 Array to append to.
 Returns any[]

Const range

range(end: number, options?: RangeOptions): number[]

Returns a number array containing numbers generated from RangeOptions.start (inclusive, defaults to 0) to end (both inclusive) where the interval between numbers will be equal to RangeOptions.step (defaults to 1).

range has standard behaviour except in the special case where the only provided argument is a negative end that is less than start, which conveniently allows decrementing from start to end.

Examples:
example
```
// Positive ranges:
range(0); //=> [0] (since `end === start`)
range(4); //=> [0, 1, 2, 3, 4]
range(4, { start: 1 }); //=> [1, 2, 3, 4]
range(10, { step: 2 }); //=> [0, 2, 4, 6, 8, 10]

// Negative ranges:
range(-4, { step: -1 }); //=> [0, -1, -2, -3, -4] (equivalent to ``)
range(-4, { step: -2 }); //=> [0, -2, -4]

// Special cases:
range(-4); //=> [0, -1, -2, -3, -4] (equivalent to `range(-4, { step: -1 })`)

// Error cases:
range(1, { step: 0 }); //=> TypeError (since prevents range)
range(-1, { start: 1, step: 2 }); //=> TypeError (since `step` is inverse to `end`)
range(-1, { start: 1, step: -1 }); //=> TypeError (since `step` is inverse to `end`)
```
throws

{TypeError} step cannot be 0.

throws

{TypeError} end cannot be less than start when step is positive.

throws

{TypeError} end cannot be greater than start whenstep is negative.

memberof

core

since

0.1.0
Parameters
- end: number
  
  Number to generate up to (inclusive).
- options: RangeOptions = {}
Returns number[]

An array containing numbers generated between start to end (both inclusive) where all numbers are seperated by an inteveral equal to step.

Const reduce

reduce(initialValue: any, transformer: (prevValue: any, value: any) => any): <T>(array: T[]) => any

Finally returns array reduced to a single value using initialValue as the starting value and transformer to provide the next value.
memberof

core

since

0.1.0

see

filter map promiseReduce reduceEntries

example
```
reduce(0, (prev, v) => prev + v)([]) //=> 0
reduce(0, (prev, v) => prev + v)([1, 2, 3]) //=> 6
reduce('', (prev, v) => prev + v)([1, 'a', 'b']) //=> '1ab'
```
Parameters
- initialValue: any
 
 Starting value (i.e., the first prevValue accepted by transformer).
- transformer: (prevValue: any, value: any) => any
 
 Accepts prevValue and returns a new prevValue.
 - - (prevValue: any, value: any): any
 - Parameters
 - prevValue: any
 - value: any
 Returns any
Returns <T>(array: T[]) => any

Finally returns array reduced to a single value.
- - <T>(array: T[]): any
 - Type parameters
 - T
 Parameters
 - array: T[]
 
 The array with elements to reduce.
 Returns any

Const reverse

reverse<T>(array: T[]): T[]

Returns array with all elements in reverse order.
memberof

core

since

0.1.0

example
```
 reverse([]); //=> []
 reverse([1, 2, 3]); //=> [3, 2, 1]
```
Type parameters
- T
Parameters
- array: T[]
  
  Array to reverse.
Returns T[]

Returns array with all elements in reverse order.

Const skip

skip(total?: number): <T>(array: T[]) => T[]

Finally returns an array containing elements after total elements.

Returns an unchanged array if total is negative.
memberof

core

since

0.1.0

see

take

example
```
 skip()([]); //=> []
 skip(1)([]); //=> []
 skip(1)([1, 2, 3]); //=> [2, 3]
 skip(2)([1, 2, 3]); //=> [3]
 skip(1)([1, 'a', 2]); //=> ['a', 3]
 skip(-1)([1, 2, 3]); //=> [1, 2, 3]
 skip(4)([1, 2, 3]); //=> []
```
Parameters
- total: number = 0
 
 number of elements to skip (optional, defaults to 0).
Returns <T>(array: T[]) => T[]

Finally returns an array containing elements after total elements.
- - <T>(array: T[]): T[]
 - Type parameters
 - T
 Parameters
 - array: T[]
 
 Array with elements to skip.
 Returns T[]

Const slice

slice(start?: number, end?: number): <T>(array: T[]) => T[]

Finally returns array containing the elements from indexes start to end.

Returns an unchanged array will be unchanged if start is negative or end is less than start or end exceeds the last index.
memberof

core

since

0.1.0

example
```
slice()([]) //=> []
slice(0, 2)([1, 2, 3]) //=> [1, 2, 3]
slice(0, 1)([1, 2, 3]) //=> [1, 2]
slice(1, 2)([1, 'a', 2]) //=> ['a', 2]
```
Parameters
- start: number = 0
 
 Index to stop at (inclusive, defaults to last index).
- Optional end: number
Returns <T>(array: T[]) => T[]

Finally returns array containing the elements from indexes start to end.
- - <T>(array: T[]): T[]
 - Type parameters
 - T
 Parameters
 - array: T[]
 Returns T[]

Const tail

tail<T>(array: T[]): T[]

Returns array without the first element.
alias

dequeue

memberof

core

since

0.1.0

see

init last head

example
```
 tail([]); //=> []
 tail([1, 2, 3]); //=> [2, 3]
```
Type parameters
- T
Parameters
- array: T[]
  
  Array to use.
Returns T[]

array without the first element.

Const take

take(total?: number): <T>(array: T[]) => T[]

Finally returns array containing elements before total (inclusive, defaults to 0) elements.

Returns an empty array if total is negative.
memberof

core

since

0.1.0

see

skip slice takeLast takePart

example
```
take()([]); //=> []
take(1)([]); //=> []
take(1)([1]); //=> [1]
take(2)([1, 2]); //=> [1, 2]
take(1)([1]); //=> [1]
take(-1)([]); //=> []
take(4)([1, 2, 3]); //=> [1, 2, 3]
```
Parameters
- total: number = 0
 
 number of elements to take (inclusive, defaults to 0).
Returns <T>(array: T[]) => T[]

Finally returns array containing elements before total elements.
- - <T>(array: T[]): T[]
 - Type parameters
 - T
 Parameters
 - array: T[]
 
 Array to use.
 Returns T[]

Const takeLast

takeLast(total?: number): <T>(array: T[]) => T[]

A reversed alternative to take, i.e., finally returns an array containing a total number of elements taken from the end of array.

Returns an empty array if total is negative.
memberof

core

since

0.1.0

see

reverse skip take

example
```
 takeLast()([]); //=> []
 takeLast(1)([]); //=> []
 takeLast(1)([1]); //=> [1]
 takeLast(2)([1, 2, 3]); //=> [3, 2]
 takeLast(1)([1]); //=> [1]
 takeLast(-1)([]); //=> []
 takeLast(4)([1, 2, 3]); //=> [3, 2, 1]
```
Parameters
- total: number = 0
 
 Number of elements to take (inclusive, defaults to 0).
Returns <T>(array: T[]) => T[]

Finally returns an array containing a total number of elements taken from the end of array.
- - <T>(array: T[]): T[]
 - Type parameters
 - T
 Parameters
 - array: T[]
 
 Array to use.
 Returns T[]

Const takePart

takePart(total?: number): <T>(array: T[]) => T[][]

Combines take & skip to finally return a 2D array where the first array contains the taken elements (i.e., before and including the total'th element) whilst the second array contains the remaining untaken elements (i.e., [[...taken], [...untaken]]).

Returns an empty 2D array (i.e., [[], []]) if total is negative.
memberof

core

since

0.1.0

see

filterPart take skip

example
```
 takePart()([]); //=> [[], []]
 takePart(1)([]); //=> [[], []]
 takePart(1)([1]); //=> [[1], []]
 takePart(2)([1, 2, 3]); //=> [[1, 2], [3]]
 takePart(1)([1]); //=> [[1], []]
 takePart(-1)([]); //=> [[], []]
 takePart(4)([1, 2, 3]); //=> [[1, 2, 3], []]
```
Parameters
- total: number = 0
 
 The number elements to take (optional, defaults to 0).
Returns <T>(array: T[]) => T[][]

Finally returns an array containing 2 arrays of the form [...taken, ...untaken], or an empty 2D array if total is negative.
- - <T>(array: T[]): T[][]
 - Type parameters
 - T
 Parameters
 - array: T[]
 
 Array to use.
 Returns T[][]

Const union

union<T>(array1: T[]): (array2: U[]) => (T | U)[]

Finally returns an array set (i.e., array without duplicates) containing all elements from array1 & array2.
memberof

core

since

0.1.0

see

concat uniq

example
```
union([])([]) //=> []
union([])([1, 2, 3]) //=> [1, 2, 3]
union([1])([1]) //=> [1]
union([1, 2])([1, 2]) //=> [1, 2]
union([1, 2])([3, 4]) //=> [1, 2, 3, 4]
union([1, 'a'])([1, 'b']) //=> [1, 'a', 'b']
```
Type parameters
- T
Parameters
- array1: T[]
 
 First array to use.
Returns (array2: U[]) => (T | U)[]

Finally returns an array set containing all unique elements from array1 & array2.
- - (array2: U[]): (T | U)[]
 - Type parameters
 - U
 Parameters
 - array2: U[]
 
 second array to use.
 Returns (T | U)[]

Const uniq

uniq<T>(array: T[]): T[]

Returns array without duplicate primitive elements (i.e., reference elements such as arrays & object elements are not tested hence are considered unique).
memberof

core

since

0.1.0

example
```
 uniq([]); //=> []
 uniq([1, 1, 'a', 'a']); //=> [1, 2]
 uniq([[], [], {}, {}]); //=> [[], [], {}, {}]
```
Type parameters
- T
Parameters
- array: T[]
  
  Array to use.
Returns T[]

Returns array without duplicate primitive elements

Boolean Functions

Const isBoolean

isBoolean(value: any): boolean

Returns true if value is a boolean, else returns false.

memberof

core

since

0.1.0

example

// Boolean values.
isBoolean(true); //=>  true
isBoolean(false); //=>  true

// Non-boolean values.
isBoolean(undefined); //=>  false
isBoolean(null); //=>  false
isBoolean(1); //=>  false
isBoolean('a'); //=>  false
isBoolean([1]); //=>  false
isBoolean({ a: 1 }); //=>  false

Parameters

value: any

Value to test.

Returns boolean

true if value is a boolean, else returns false.

Function Functions

Const also

also<T>(value: T, handler: (it: T) => T): T

Runs handler, which receives a contextual object it representing value, before returning value.

Useful for running statements before assigning the resulting object to a variable:

example

const numbers = [1, 2];
const threeNumbers = also(numbers, it => {
  console.log(it); // Prints `[1, 2]`
  it.append(3);
  console.log(it); // Prints `[1, 2, 3]`
  return it;
});
threeNumbers; //=> [1, 2, 3]

memberof

core

since

1.0.0

example

also() //=> Error
also('foo', it => {
 it = `${it} bar`
 return it;
}); //=> 'foo bar'

Type parameters

Parameters

value: T
handler: (it: T) => T
- - (it: T): T
  - Parameters
    - it: T
    Returns T

Returns T

Returns value.

Const compose

compose<Functions>(...functions: Functions): (initialValue?: any) => LastReturnType

Sequentially applies functions in a mathematical right-to-left order with a beginning value of initialValue to finally return the output of the first (i.e., left-most) function in functions.

Useful for composing a series of functions on an initial value where the output of a function is passed as an argument to the next function until a final result is returned by the final function (N.B., the first function in functions is the final function since compose uses mathematical right-to-left composition):
example
```
// Composing on number.
const isEven = n => n % 2 === 0;
const double = n => n * 2;
const isDoubledNumberEven = compose(isEven, double);
isDoubledNumberEven(1) //=> true

Composing on numbers.
const keepEvenNumbers = numbers => numbers.filter(isEven)
const doubleNumbers = numbers => numbers.map(double)
const doubleEvenNumbers = compose(doubleNumbers, keepEvenNumbers);
doubleEvenNumbers([1, 2, 3]); // [4]
```
memberof

core

since

0.1.0

see

pipe

example
```
const isEven = n => n % 2 === 0;
const double = n => n * 2;
const doubleNumbers = numbers => numbers.map(double);

compose()() //=> undefined
compose(isEven)(1) //=> false
compose(isEven, double)(1) //=> true
compose(doubleNumbers)([1, 2, 3]) //=> [2, 4, 6]
```
Type parameters
- Functions: AnyFunction[]
Parameters
- Rest ...functions: Functions
  
  Unary functions to compose (optional, defaults to []).
Returns (initialValue?: any) => LastReturnType

Finally returns the output of the first (i.e., left-most) function in functions.
- - (initialValue?: any): LastReturnType
  - Parameters
    - Optional initialValue: any
      
      The initial value that is passed to the first function in functions (optional, defaults to undefined).
    Returns LastReturnType

Const contra

contra(..._: any[]): boolean

Always returns false regardless of passed arguments.

Useful for defaulting an anonymous function to false:

example

// Default `predicate` function to always return `false` hence `filterNumbers` defaults to
remove all elements if no `predicate`.
const filterNumbers = (array = [], predicate = contra) => array.filter(predicate);
const numbers = [1, 2, 3];
const isEven = n => n % 2 === 0;
filterNumbers(numbers, isEven); //=> [2]
// Defaulted to no elements via `contra`:
filterNumbers(numbers); //=> []

memberof

core

since

0.1.0

see

tauto

example

contra() //=> false
contra('foo', 'bar') //=> false

Parameters

Rest ..._: any[]

Returns boolean

false regardless of passed arguments.

Const ifElse

ifElse<TValue, TFinal>(predicate?: (value?: TValue) => boolean, onTrue?: (value?: TValue) => TFinal, onFalse?: (value?: TValue) => TFinal): (value?: TValue) => TFinal

Finally returns onTrue's output if predicate returns true, else returns onFalse's output.

Useful when conditionally returning a new value based on a condition:
example
```
const firstElement = array => array[0];
const isEven = n % 2 === 0;
const onEven = () => 'even';
const onOdd = () => 'odd';

const firstNumberEvenString = compose(ifElse(isEven, onEven, onOdd), firstElement);
firstNumberEvenString([1, 2, 3]) //=> 'odd'
firstNumberEvenString([2, 3]) //=> 'even'
```
memberof

core

since

0.1.0

see

tryOr

example
```
const isEven = n => n % 2 === 0;
const onEven = () => 'even';
const onOdd = () => 'odd';

ifElse()(); //=> undefined (via `onFalse`)
ifElse()(2); //=> undefined (via `onFalse`)
ifElse(isEven)(2); //=> undefined (via `onTrue`)
ifElse(isEven, onEven)(2); //=> 'even'
ifElse(isEven, onEven, onOdd)(2) //=> 'even'
ifElse(isEven, onEven, onOdd)(1) //=> 'odd'
```
Type parameters
- TValue
- TFinal
Parameters
- predicate: (value?: TValue) => boolean = ...
  
  Returns a boolean based on value where true triggers onTrue & false triggers onFalse, (optional, defaults to return false). optional value (optional, defaults to return value).
  - - (value?: TValue): boolean
    - Parameters
      - Optional value: TValue
      Returns boolean
- onTrue: (value?: TValue) => TFinal = ...
  
  Returns the new value if predicate returns true (optional, defaults to return undefined).
  - - (value?: TValue): TFinal
    - Parameters
      - Optional value: TValue
      Returns TFinal
- onFalse: (value?: TValue) => TFinal = ...
  
  Returns the new value if predicate returns false (optional, defaults to return undefined). tryer (optional, defaults to return value). optional value (optional, defaults to return value).
  - - (value?: TValue): TFinal
    - Parameters
      - Optional value: TValue
      Returns TFinal
Returns (value?: TValue) => TFinal

Finally returns output of tryer if no errors are thrown, else returns the output of defaulter.
- - (value?: TValue): TFinal
  - Parameters
    - Optional value: TValue
      
      The value to test via predicate.
    Returns TFinal

Const isFunction

isFunction(value?: any): boolean

Returns true if value is a function (via typeof), else return `false.

memberof

core

since

0.1.0

example

// Function values.
isFunction(() => undefined) //=> true

// Non-function values.
isFunction() //=> false
isFunction(undefined) //=> false
isFunction(true) //=> false
isFunction(1) //=> false
isFunction('foo') //=> false
isFunction(null) //=> false
isFunction({ a: 1, b: 2, c: 3 }) //=> false
isFunction([1, 2, 3]) //=> false

Parameters

Optional value: any

Value to check.

Returns boolean

true if value is a function (via typeof), else return `false

Const isPromise

isPromise(value?: any): boolean

Returns true if value is an instance of Promise, else returns false.

memberof

core

since

0.1.0

see

isFunction

example

// Promises values.
isPromise(Promise.resolve(1)) //=> true
isPromise(Promise.reject(1)) //=> true
isPromise(new Promise(() => undefined)) //=> true
isPromise(new Promise(r => r(1))) //=> true
isPromise(new Promise(r => r(1))) //=> true

// Non-promises values.
isPromise() //=> false
isPromise(undefined) //=> false
isPromise(true) //=> false
isPromise(1) //=> false
isPromise('foo') //=> false
isPromise(() => undefined) //=> false
isPromise(() => Promise.resolve(1)) //=> false
isPromise(async () => 1) //=> false
isPromise(async () => await 1) //=> false
isPromise(null) //=> false
isPromise({ a: 1, b: 2, c: 3 }) //=> false
isPromise([1, 2, 3]) //=> false

Parameters

Optional value: any

Value to check.

Returns boolean

true if value is a Promise, else returns false.

Const negate

negate(predicate?: (...args: any[]) => boolean): (...args: any[]) => boolean

Finally returns the inverted boolean returned by predicate.

Useful for inverting predicate functions:

example

// Negating 1 argument `predicate`.
const isEven = n => n % 2 === 0; // Original predicate.
isEven(2); //=> true
const isOdd = negate(isEven); // Negated predicate.
isOdd(2); //=> false

// Negating 2 argument `predicate`.
const isEvenArgs = (...args) => args.length % 2 === 0;
isEvenArgs('foo', 'bar') // true
const isOddArgs = negate(isEvenArgs);
isOddArgs('foo', 'bar'); //=> false

memberof

core

since

0.1.0

see

contra logicalNot tauto

example

negate() //=> false
negate(() => true) //=> false
negate(() => false) //=> true
const isEvenArgs = (...args) => args.length % 2 === 0;
isEvenArgs('foo', 'bar') // true
negate(isEvenArgs)('foo', bar'); //=> false

Parameters

predicate: (...args: any[]) => boolean = ...

Non-curried function that returns a boolean to negate (optional, defaults to return true)
- - (...args: any[]): boolean
  - Parameters
    - Rest ...args: any[]
    Returns boolean

Returns (...args: any[]) => boolean

Finally returns the inverted boolean returned by predicate.

- (...args: any[]): boolean
- Parameters
  - Rest ...args: any[]
  Returns boolean

Const noop

noop(..._: any[]): undefined

Always returns undefined regardless of passed arguments.

Useful for providing a function as a placeholder without side effects:
example
```
// ...
if (disabled) button.onClick = noop; // `noop` is called on click but no operation is performed.
```
memberof

core

since

0.1.0

example
```
noop() //=> undefined
noop('foo', 'bar') //=> undefined
```
Parameters
- Rest ..._: any[]
Returns undefined

undefined regardless of passed arguments.

Const opRuntime

opRuntime(testFunction: AnyFunction): Promise<number>

Returns a Promise that resolves to the time in milliseconds for testFunction to return.
memberof

core

since

0.1.0

see

delayFor

example
```
const runtimeMs = 2000;
const longRunningOperation = async () => await new Promise(r => setTimeout(r, runtimeMs);

opRuntime(longRunningOperation); //=> t where t >= runtimeMs
```
Parameters
- testFunction: AnyFunction
 
 function to test.
Returns Promise<number>

A Promise that resolves to the time in milliseconds for testFunction to return.

Const pipe

pipe<Functions>(...functions: Functions): (initialValue?: any) => LastReturnType

Identical to compose but reverses the order of functions, i.e., sequentially applies functions in a computational left-to-right order with a beginning value of initialValue.
memberof

core

since

0.1.0

example
```
const isEven = n => n % 2 === 0;
const double = n => n * 2;
const doubleNumbers = numbers => numbers.map(double);

pipe()() //=> undefined
pipe(isEven)(1) //=> false
pipe(double, isEven)(1) //=> true
pipe(doubleNumbers)([1, 2, 3]) //=> [2, 4, 6]
```
Type parameters
- Functions: AnyFunction[]
Parameters
- Rest ...functions: Functions
  
  Unary functions to pipe (optional, defaults to []).
Returns (initialValue?: any) => LastReturnType

Finally returns the output of the first (i.e., right-most) function in functions.
- - (initialValue?: any): LastReturnType
  - Parameters
    - Optional initialValue: any
      
      The initial value that is passed to the first function in functions (optional, defaults to undefined).
    Returns LastReturnType

Const promiseLog

promiseLog(message: string, loggerFunction?: LoggerFunction): <T>(promise: Promise<T>) => Promise<any>

Convenient alternative to using tapLog with Promises. I.e., passes message & resolved promise value to loggerFunction to allow logging before finally returning the unchanged promise.

Useful for logging a Promise value before returning it unchanged for further use with other promise functions (e.g., during composition):
example
```
const fetchUsers = () => {
 // ...returns Promise<any[]>.
};
const firstElement = array = array[0];
const logThenReturnFirstUser = () => compose(firstElement, promiseLog)(fetchUsers());
logThenReturnFirstUser(); //=> (logs users then returns first user)
```
memberof

core

since

0.1.0

see

tapLog

example
```
promiseLog('foo')(Promise.resolve(1)) //=> (logs `foo` & `1` then returns `Promise`)
```
Parameters
- message: string
 
 Message passed to loggerFunction.
- loggerFunction: LoggerFunction = ...
 
 LoggerFunction to pass message and resolved promise to (optional, defaults to console.debug, has no effect on the finally returned value).
Returns <T>(promise: Promise<T>) => Promise<any>

Finally returns the unchanged promise.
- - <T>(promise: Promise<T>): Promise<any>
 - Type parameters
 - T
 Parameters
 - promise: Promise<T>
 
 The Promise to log.
 Returns Promise<any>

Const promiseTryOr

promiseTryOr<TValue, TFinal>(tryer?: (value?: TValue) => Promise<TFinal>, defaulter?: (value?: TValue, error?: unknown) => TFinal): (value?: TValue) => Promise<TFinal>

Asynchronous alternative to tryOr. I.e., finally returns output of tryer if no errors are thrown, else returns the output of defaulter.

Useful for trying potentially errorful asynchronous operations and returning the successful output or defaulting an errorful output to a specific value:
example
```
// Errorful asynchronous function.
const getFileContents = (filePath) => new Promise((__, reject) => setTimeout(
 () => reject('error'), 100
));
const defaultFileContents = (value, error) => {
 // ...optionally handle error.
 return 'foo'; // Provide default value.
};
const fileContentsOrDefault = promiseTryOr(getFileContents, defaultFileContents);
const nonExistantFilePath = undefined;
// Errorful output caught and defaulted.
await fileContentsOrDefault(nonExistantFilePath); //=> 'foo'
```
memberof

core

since

0.1.0

see

tryOr
Type parameters
- TValue
- TFinal
Parameters
- tryer: (value?: TValue) => Promise<TFinal> = ...
 
 Asynchronous function (accepting value) that is tried to return a final value if no errors occur.
 - - (value?: TValue): Promise<TFinal>
 - Parameters
 - Optional value: TValue
 Returns Promise<TFinal>
- defaulter: (value?: TValue, error?: unknown) => TFinal = ...
 
 See tryOr
 - - (value?: TValue, error?: unknown): TFinal
 - Parameters
 - Optional value: TValue
 - Optional error: unknown
 Returns TFinal
Returns (value?: TValue) => Promise<TFinal>

Finally returns a Promise containing that resolves to the output of tryer if no errors are thrown, else resolves to the output of defaulter.
- - (value?: TValue): Promise<TFinal>
 - Parameters
 - Optional value: TValue
 
 See tryOr
 Returns Promise<TFinal>

Const runNow

runNow(functionToRun: AnyFunction): any

Immediately runs functionToRun and returns its output.

Serves as a convenient alternative to using an IFFE (Immediately invoked function expression) whilst reducing the number of parantheses to achieve the same behaviour.

Useful for immediatley running a function:

example

// Immediately run `main` function:
const main = () => {
    // ...
};
runNow(main);

// Immediately initialise variable via function:
const getEnvironment = (defaultValue) => {
    try {
         throw new Error('Not found'); // Assuming runtime value fails.
    } catch (e: unknown) {
        return defaultValue;
    }
};
const environment = runNow(() => getEnvironment('development')); // Initialise variable.
environment; //=> 'development'

memberof

core

since

0.1.0

example

runNow() //=> undefined
runNow(() => double(1)) //=> 2

Parameters

functionToRun: AnyFunction

Function to run (optional, defaults to return undefined).

Returns any

Output from functionToRun.

Const runStringTypeValues

runStringTypeValues(valueMapper: (testValue: any, stringTypeName: StringType) => any): Record<string, Record<string, any>>

Returns AllStringTypeExampleValues with the values of all StringTypeExampleValues updated using valueMapper.

Useful for testing a function on all possible string type values based on StringTypeDetails.

example

// Expect `stringTypeIs` to return `true` when given correct `stringTypeName` and value:

// E.g., `expected = { boolean: { true: v, ... }, ... };` where `v` was updated to `true`.
const expected = runStringTypeValues(() => true);

// Run `stringTypeIs` on all string type values:

const results = runStringTypeValues(
// E.g., `expected = { boolean: { true: v, ... }, ... };` where `v` was updated to the output of `stringTypeIs`.
    (testValue, stringTypeName) => stringTypeIs(stringTypeName)(testValue)
);

// Compare expectations, e.g.:
expect(results).toStrictEqual(expected);

memberof

core

since

0.1.0

see

runTestCases

Parameters

valueMapper: (testValue: any, stringTypeName: StringType) => any

Returns a new value for each StringTypeExampleValues.
- - (testValue: any, stringTypeName: StringType): any
  - Parameters
    - testValue: any
    - stringTypeName: StringType
    Returns any

Returns Record<string, Record<string, any>>

AllStringTypeExampleValues with the values of all StringTypeExampleValues updated using valueMapper.

Const runTestCases

runTestCases(testFunction: AnyFunction, testCases?: TestCases): TestCases

Finally returns testCases where TestCaseDetail.expectedResult in all entries are updated using testFunction.

Each ArgSet in TestCaseDetail.argSets will be passed to successive calls of testFunction to support curried functions:

example

const addNumbers = (a: number) => (b: number) => a + b; // Curried `testFunction`.
const expectedTestCases: TestCases = {
    'adds numbers': {
        argSets: [ // Arguments for each call of `testFunction`.
            [1], // Arguments passed to 1st call of `testFunction`, i.e., `addNumbers(1)`.
            [2], // I.e.: `addNumbers(1)(2)`.
        ],
        expectedResult: 3,
    },
    // ...
};

const resultTestCases = runTestCases(addNumbers, expectedTestCases);

Useful for collecting a function's output for several test values in an updated TestCase object that can be logged or compared against the original TestCase object:

example

// Setup using 1 argument for a non-curried `testFunction`:
const doubleNumber = (n: number) => n * 2;
const expectedTestCases: TestCases = {
    'doubles negative': {
        argSets: [[-1]],
        expectedResult: -2,
    },
    'doubles number': {
        testValue: [[1]],
        expectedResult: 2,
    },
};

// Results:
const doubleNumberResults = runTestCases(doubleNumber, expectedTestCaseData);

// Inspection:
console.log(doubleNumberResults);
// Compare expected results to test case results, e.g.:
expect(doubleNumberResults).toStrictEqual(expectedTestCaseData);

memberof

core

since

0.1.0

Parameters

testFunction: AnyFunction

Function to test via updating test cases.
testCases: TestCases = {}

TestCases to run.

Returns TestCases

Finally returns testCases where TestCaseDetail.expectedResult in all entries are updated using testFunction.

Const tap

tap<T, U>(transformer: (value: T) => U): (value: T) => U

Uses transformer to finally return a new value for value.
memberof

core

since

0.1.0

example
```
tap(v => v * 2)(2) //=> 4
```
Type parameters
- T
- U
Parameters
- transformer: (value: T) => U
  
  Returns a new value.
  - - (value: T): U
    - Parameters
      - value: T
      Returns U
Returns (value: T) => U

Finally returns a new value.
- - (value: T): U
  - Parameters
    - value: T
      
      Value to test.
    Returns U

Const tapLog

tapLog(message: string, loggerFunction?: LoggerFunction): (...args: any[]) => any

Passes message and args to a loggerFunction that is run before finally returning the first argument in args.

Serves as a convenient and extended alternative to passing a logger function to tap to log an argument for inspection before returning it for further usage.
memberof

core

since

0.1.0

see

promiseLog tap

example
```
// Using default logger.
tapLog('foo')() //=> undefined
tapLog('foo')('bar') //=> 'bar'
tapLog('foo')('bar', 'baz') //=> 'bar'

// Using custom logger.
const errorLogger: LoggerFunction  = (message, ...args) => console.error(message);
tapLog('foo', errorLogger)('bar') //=> 'bar' (logs `foo` via `console.error`)
```
Parameters
- message: string
  
  Message passed to loggerFunction.
- loggerFunction: LoggerFunction = ...
  
  LoggerFunction to pass message and args to (optional, defaults to console.debug, has no effect on the finally returned value).
Returns (...args: any[]) => any

Finally returns the first argument in args.
- - (...args: any[]): any
  - Parameters
    - Rest ...args: any[]
      
      All arguments to log where the first argument is finally returned.
    Returns any

Const tauto

tauto(..._: any[]): boolean

Always returns true regardless of passes arguments.

Useful for defaulting an anonymous function to false:

example

// Default `predicate` function to always return `true` hence `filterNumbers` defaults to
keep all elements if no `predicate`.
const filterNumbers = (array = [], predicate = tauto) => array.filter(predicate);
const numbers = [1, 2, 3];
const isEven = n => n % 2 === 0;
filterNumbers(numbers, isEven); //=> [2]
// Defaulted to keep elements via `tauto`:
filterNumbers(numbers); //=> [1, 2, 3]

memberof

core

since

0.1.0

see

identity contra

example

tauto() //=> true
tauto('foo', 'bar') //=> true

Parameters

Rest ..._: any[]

Returns boolean

true regardless of passes arguments.

Const throwIf

throwIf<TValue>(predicate?: (value: TValue) => boolean, error?: Error): (value: TValue) => TValue

Finally returns value if predicate returns false, else throws error.

Useful for halting an invalid composition:
example
```
const isOdd = n => n % 2 !== 0;
const double = n => n * 2;
const doubleEvenNumber = compose(double, throwIf(isOdd, 'Number must be even'))
doubleEvenNumber(2); //=> 4
doubleEvenNumber(1) //=> Error('Number must be even')
```
throws

{Error} Throws error.

memberof

core

since

0.1.0

see

tap tryOr

example
```
const isOdd = n => n % 2 !== 0;

throwIf(isOdd)(2) //=> 2
throwIf(isOdd)(1) //=> Error('throwIf: Predicate is true for << 1 >>')
throwIf(isOdd, new TypeError('Number must be even'))(1) //=> TypeError('Number must be even')
```
Type parameters
- TValue
Parameters
- predicate: (value: TValue) => boolean = ...
 
 Returns true to throw error (optional, defaults to return true), or returns false to return value.
 - - (value: TValue): boolean
 - Parameters
 - value: TValue
 Returns boolean
- error: Error = ...
 
 Error to throw (optional, defaults to a generic error).
Returns (value: TValue) => TValue

Finally returns value is predicate is false, else throws.
- - (value: TValue): TValue
 - Parameters
 - value: TValue
 
 Value to test.
 Returns TValue

Const tryOr

tryOr<TValue, TFinal>(tryer?: (value?: TValue) => TFinal, defaulter?: (value?: TValue, error?: unknown) => TFinal): (value?: TValue) => TFinal

Finally returns output of tryer if no errors are thrown, else returns the output of defaulter.

Useful for trying potentially errorful operations and returning the successful output or defaulting an errorful output to a specific value:
example
```
const getFileContents = (filePath) => { // Errorful function.
    // ...
};
const defaultFileContents = (value, error) => {
    // ...optionally handle error.
    return 'foo'; // Provide default value.
};
const fileContentsOrDefault = tryOr(getFileContents, defaultFileContents);
const nonExistantFilePath = undefined;
fileContentsOrDefault(nonExistantFilePath); //=> 'foo' // Errorful output caught and defaulted.
```
memberof

core

since

0.1.0

see

throwIf promiseTryOr

example
```
const trySafe = v => v;
const tryUnsafe = () => {
    thow new Error();
};
const defaultFoo = () => 'foo';

tryOr()() //=> undefined (via `tryer`)
tryOr(undefined, defaultFoo)(2) //=> 2 (via `tryer`)
tryOr(trySafe)(2) //=> 2
tryOr(tryUnsafe)(2) //=> 2 (via `defaulter`)
tryOr(tryUnsafe, defaultFoo)(2) //=> 'foo'
```
Type parameters
- TValue
- TFinal
Parameters
- tryer: (value?: TValue) => TFinal = ...
  
  Tries to return a new value based on optional value (optional, defaults to return value).
  - - (value?: TValue): TFinal
    - Parameters
      - Optional value: TValue
      Returns TFinal
- defaulter: (value?: TValue, error?: unknown) => TFinal = ...
  
  Returns the default value if an error occurs in tryer (optional, defaults to return value). optional value (optional, defaults to return value).
  - - (value?: TValue, error?: unknown): TFinal
    - Parameters
      - Optional value: TValue
      - Optional error: unknown
      Returns TFinal
Returns (value?: TValue) => TFinal

Finally returns output of tryer if no errors are thrown, else returns the output of defaulter.
- - (value?: TValue): TFinal
  - Parameters
    - Optional value: TValue
      
      The value to try a potentially errorful operation on.
    Returns TFinal

Logic Functions

Const assertStrictEquals

assertStrictEquals(value1?: any, errorMessage?: string): (value2?: any) => void

Convenience function similar to strictEquals but throws an error if value1 is strictly equal (via ===) to value2, else returns void.
throws

{TypeError} value must be a hex string.

memberof

core

since

1.0.0

example
```
assertStrictEquals()() //=> undefined
assertStrictEquals()(1) //=> Error
assertStrictEquals(1)() //=> Error
assertStrictEquals(1)(1) //=> undefined
assertStrictEquals(1)(2) //=> Error

// Config.
assertStrictEquals(1, 'foo bar')(2) //=> Error where message includes 'foo bar'

// Objects (similar for arrays, functions, & symbols).
assertStrictEquals({ a: 1 })({ a: 1 }) //=> Error
const myObject = { a: 1 }
assertStrictEquals(myObject)(myObject) //=> undefined
```
Parameters
- Optional value1: any
  
  First value to compare.
- Optional errorMessage: string
  
  Optional message to include in thrown error.
Returns (value2?: any) => void

Finally returns true if value1 is strictly equal (via ===) to value2, else returns false.
- - (value2?: any): void
  - Parameters
    - Optional value2: any
      
      Second value to compare.
    Returns void

Const getStringType

getStringType(value?: any): "string" | "number" | "bigint" | "boolean" | "symbol" | "undefined" | "object" | "function"

Returns a string (via typeof) indicating the type of value.

memberof

core

since

0.1.0

see

stringTypeIs

example

getStringType() //=> 'undefined'
getStringType(undefined) //=> 'undefined'
getStringType(true) //=> 'boolean'
getStringType(1) //=> 'number'
getStringType('foo') //=> 'string'
getStringType({ a: 1, b: 2, c: 3 }) //=> 'object'
getStringType(null) //=> 'object'

Parameters

Optional value: any

The value to check.

Returns "string" | "number" | "bigint" | "boolean" | "symbol" | "undefined" | "object" | "function"

String indicating the type of value.

Const identity

identity<T>(identityValue: T, ..._: any[]): T

Always returns the identityValue (i.e., the first argument).
memberof

core

since

0.1.0

see

contra noop tauto

example
```
identity(1); // => 1
identity(1, 2); // => 1
```
Type parameters
- T
Parameters
- identityValue: T
  
  Value to return.
- Rest ..._: any[]
Returns T

Always returns the identityValue (i.e., the first argument).

Const isInstanceOf

isInstanceOf(expectedInstanceType?: any): (value?: any) => boolean

Finally returns true if value is an instance (via instanceof) of expectedInstanceType.
memberof

core

since

0.1.0

example
```
class User { name = 'foo'; }
class Admin extends User { settings = 'foo'; }

isInstanceOf()() //=> false
isInstanceOf()(undefined) //=> false
isInstanceOf(User)(undefined) //=> false
isInstanceOf(User)(new User()) //=> true
isInstanceOf(User)(new Admin()) //=> true
```
Parameters
- Optional expectedInstanceType: any
  
  The expected instance type.
Returns (value?: any) => boolean

true if values's string type is equal to expectedStringType
- - (value?: any): boolean
  - Parameters
    - Optional value: any
      
      The value to check the instance type of.
    Returns boolean

Const isNil

isNil(value?: any): boolean

Returns true if value is either null or undefined, else returns false.

memberof

core

since

0.1.0

example

// Nil values.
isNil(undefined) //=> true
isNil(null) //=> true

// Non-nil values.
isNil([]) //=> false
isNil([1, '2', 3]) //=> false
isNil({}) //=> false
isNil({ a: 1, b: '2', c: 3 }) //=> false
isNil('') //=> false
isNil('foo bar baz') //=> false
isNil(true) //=> false
isNil(false) //=> false
isNil(-1) //=> false
isNil(0) //=> false
isNil(1) //=> false
isNil(1.1) //=> false

Parameters

Optional value: any

Value to test.

Returns boolean

true if value is either null or undefined, else returns false.

Const logicalAnd

logicalAnd(value1?: boolean): (value2?: boolean) => boolean

Finally returns true if both value1 & value2 are true, else returns false.
memberof

core

since

0.1.0

example
```
logicalAnd()() //=> false
logicalAnd(true)() //=> false
logicalAnd()(true) //=> false
logicalAnd(false)(false) //=> false
logicalAnd(true)(false) //=> false
logicalAnd(true)(true) //=> true
```
Parameters
- Optional value1: boolean
  
  First boolean to compare.
Returns (value2?: boolean) => boolean

Finally returns true if both value1 & value2 are true, else returns false.
- - (value2?: boolean): boolean
  - Parameters
    - Optional value2: boolean
      
      Second boolean to compare.
    Returns boolean

Const logicalNot

logicalNot(value: boolean): boolean

Inverts (via !) boolean value, i.e., returns true if value is false, else returns false.
memberof

core

since

0.1.0

example
```
logicalNot(false) //=> true
logicalNot(true) //=> false
```
Parameters
- value: boolean
  
  boolean to invert.
Returns boolean

Returns true if value is false, else returns false.

Const logicalOr

logicalOr(value1?: boolean): (value2?: boolean) => boolean

Finally returns true if either or both value1 & value2 are true, else returns false.
memberof

core

since

0.1.0

example
```
logicalOr()() //=> false
logicalOr(true)() //=> true
logicalOr()(true) //=> true
logicalOr(false)(false) //=> false
logicalOr(true)(false) //=> true
logicalAnd(true)(true) //=> true
```
Parameters
- Optional value1: boolean
  
  First boolean to compare.
Returns (value2?: boolean) => boolean

Finally returns true if either or both value1 & value2 are true, else returns false.
- - (value2?: boolean): boolean
  - Parameters
    - Optional value2: boolean
      
      Second boolean to compare.
    Returns boolean

Const maxCallStackSize

maxCallStackSize(): number

Returns the max number of calls for the call stack.
memberof

core

since

0.1.0

example
```
maxCallStackSize() //=> n where n is a positive integer
```
Returns number

Max number of calls for the call stack.

Const strictEquals

strictEquals(value1?: any): (value2?: any) => boolean

Finally returns true if value1 is strictly equal (via ===) to value2, else returns false.

memberof

core

since

0.1.0

example

strictEquals()() //=> true
strictEquals()(1) //=> false
strictEquals(1)() //=> false
strictEquals(1)(1) //=> true
strictEquals(1)(2) //=> false
strictEquals(undefined)(undefined) //=> true
strictEquals(true)(true) //=> true
strictEquals('foo')('foo') //=> true
strictEquals({})({}) //=> true
strictEquals({ a: 1, b: 2, c: 3 })({ a: 1, b: 2, c: 3 }) //=> true
strictEquals([])([]) //=> true
strictEquals([1, 2, 3])([1, 2, 3]) //=> true

Parameters

Optional value1: any

First value to compare.

Returns (value2?: any) => boolean

Finally returns true if value1 is strictly equal (via ===) to value2, else returns false.

- (value2?: any): boolean
- Parameters
  - Optional value2: any
    
    Second value to compare.
  Returns boolean

Const stringTypeIs

stringTypeIs(expectedStringType?: string): (value?: any) => boolean

Finally returns true if value's string type (i.e., returned by typeof) is equal to expectedStringType.
memberof

core

since

0.1.0

example
```
stringTypeIs()() //=> false
stringTypeIs()(undefined) //=> false
stringTypeIs('undefined')(null) //=> false
stringTypeIs('undefined')(undefined) //=> true
stringTypeIs('boolean')(true) //=> true
stringTypeIs('number')(1) //=> true
stringTypeIs('string')('foo') //=> true
stringTypeIs('object')({ a: 1, b: 2, c: 3 }) //=> true
stringTypeIs('object')(null) //=> true
```
Parameters
- Optional expectedStringType: string
  
  The expected string type.
Returns (value?: any) => boolean

Finally returns true if values's string type is equal to expectedStringType.
- - (value?: any): boolean
  - Parameters
    - Optional value: any
      
      The value to check the stirng type of.
    Returns boolean

Const valueIf

valueIf<T>(predicate: (value: T) => boolean, defaultValue: T): (value: T) => T

Finally returns value if predicate returns true, else returns defaultValue.
memberof

core

since

0.1.0

see

arrayIf stringIf

example
```
valueIf(() => true, [])[1, 2, 3]); //=> [1, 2, 3]
valueIf(() => false, [])[1, 2, 3]); //=> []
```
Type parameters
- T
Parameters
- predicate: (value: T) => boolean
  
  Boolean function to determine which value to return.
  - - (value: T): boolean
    - Parameters
      - value: T
      Returns boolean
- defaultValue: T
  
  The default value to return.
Returns (value: T) => T

Finally returns value if predicate returns true, else returns defaultValue.
- - (value: T): T
  - Parameters
    - value: T
    Returns T

Number Functions

Const add

add(value1: number, preserveMaxDp?: boolean): (value2: number) => undefined | number

Returns the sum of adding value2 to value1.
memberof

core

since

0.1.0

see

increment

example
```
// Integers.
add(0)(0) //=> 0
add(1)(1) //=> 2
add(-1)(-1) //=> -2

// Floats.
add(0)(0.2) //=> 0.2
add(0.2)(0.2) //=> 0.4
add(-0.2, -0.2) //=> -0.4

// Preserving max decimal points.
add(0.1)(0.2) === 0.3 //=> false
add(0.1, true)(0.2) === 0.3 //=> true
```
Parameters
- value1: number
  
  The first number to add to.
- preserveMaxDp: boolean = false
Returns (value2: number) => undefined | number

The sum of both numbers.
- - (value2: number): undefined | number
  - Parameters
    - value2: number
      
      The second number to add.
    Returns undefined | number

Const anyPass

anyPass(predicates: PredicateFunction[]): <T>(values: T[]) => boolean

Returns true if 1 or more values in values returns true for all predicate functions in predicates.
memberof

core

since

1.0.0

see

anyTrue

example
```
// Integers.
const isZero = n => n === 0;
anyPass([isEven])([]) //=> false
anyPass([isEven])([1, 3, 5]) //=> false
anyPass([isEven])([1, 2, 3]) //=> true
anyPass([isEven])([2, 4, 5]) //=> true
anyPass([isEven, isZero])([0, 2, 4]) //=> true
```
Parameters
- predicates: PredicateFunction[]
 
 The predicate functions that values are checked against.
Returns <T>(values: T[]) => boolean

true if 1 or more values in values returns true for all predicate functions in predicates.
- - <T>(values: T[]): boolean
 - Type parameters
 - T
 Parameters
 - values: T[]
 
 The values to check.
 Returns boolean

Const clamp

clamp(min: number, max: number): (value: number) => number

Restricts a given value to be inclusively within the range of min to max.
memberof

core

since

1.0.0

see

range

example
```
clamp(1, 3)(-1) //=> 1
clamp(1, 3)(1) //=> 1
clamp(1, 3)(3) //=> 3
clamp(1, 3)(4) //=> 3
```
Parameters
- min: number
  
  Minimum value of the range.
- max: number
  
  Maximum value of the range.
Returns (value: number) => number

Finally returns a number inclusively within the range of min to max.
- - (value: number): number
  - Parameters
    - value: number
    Returns number

Const decrement

decrement(value: number): number

Returns value decremented by 1.

memberof

core

since

0.1.0

see

increment

example

// Integers.
decrement(-1) //=> -2
decrement(0) //=> -1
decrement(1) //=> 0

// Floats.
decrement(-1.1) //=> -2.1
decrement(0.1) //=> -0.1
decrement(1.1) //=> 0.1

// Others.
decrement(NaN) //=> NaN
decrement(Infinity) //=> Infinity

Parameters

value: number

The number to decrement.

Returns number

value decremented by 1.

Const equals

equals(value1: number): (value2: number) => boolean

number-specific (only accepts values of type number) alternative to strictEquals (which compares values of type any). I.e., Finally returns true if value1 is numberically equal to value2, else returns false.
memberof

core

since

0.1.0

see

strictEquals

example
```
equals(1)(1) //=> true
equals(1)(2) //=> false
equals(2)(1) //=> false
```
Parameters
- value1: number
  
  First value to compare.
Returns (value2: number) => boolean

Finally returns true if value1 is numberically equal to value2, else returns false.
- - (value2: number): boolean
  - Parameters
    - value2: number
      
      Second value to compare.
    Returns boolean

Const increment

increment(value: number): number

Returns value incremented by 1.

memberof

core

since

0.1.0

see

decrement

example

// Integers.
increment(-1) //=> 0
increment(0) //=> 1
increment(1) //=> 2

// Floats.
increment(-1.1) //=> -0.1
increment(0.1) //=> 1.1
increment(1.1) //=> 2.1

// Others.
increment(NaN) //=> NaN
increment(Infinity) //=> Infinity

Parameters

value: number

The number to increment.

Returns number

value incremented by 1.

Const integerToHexColor

integerToHexColor(value?: number): string

Returns value as a valid hexadecimal color string where the hexadecimal value is within the range of 000000 to FFFFFF. Values below this range return the bottom of the range whilst values exceeding this range return the top of the range.
memberof

core

since

0.1.0

see

hexColorToInteger isHexColor

example
```
 integerToHexColor(); //=> `#000000`
 integerToHexColor(15); //=> `#00000F`
 integerToHexColor(-1); //=> `#000000`
 integerToHexColor(Infinity); //=> `#FFFFFF`
```
Parameters
- value: number = 0
  
  Integer to convert.
Returns string

value as a valid hexadecimal color string

Const isEven

isEven(value: number): boolean

Returns true if value is even, else returns false.

memberof

core

since

1.0.0

example

// Integers.
isEven(0) //=> true
isEven(-1) //=> false
isEven(1) //=> false
isEven(-2) //=> true
isEven(2) //=> true

// Floats.
isEven(-1.1) //=> false
isEven(1.1) //=> false
isEven(-2.2) //=> true
isEven(2.2) //=> true

Parameters

value: number

The number to check.

Returns boolean

true if value is even, else returns false.

Const isFloat

isFloat(value?: any): boolean

Returns true if value is a float, else returns false.

memberof

core

since

0.1.0

see

isInteger

example

// Float values.
isFloat(-1.1) //=> false
isFloat(1.1) //=> false

// Non-float values.
isFloat() //=> false
isFloat(undefined) //=> false
isFloat(null) //=> false
isFloat([]) //=> false
isFloat([1, '2', 3]) //=> false
isFloat({}) //=> false
isFloat({ a: 1, b: '2', c: 3 }) //=> false
isFloat('') //=> false
isFloat('foo bar baz') //=> false
isFloat(true) //=> false
isFloat(false) //=> false
isFloat(-1) //=> false
isFloat(0) //=> false
isFloat(0.0) //=> false (since JS treats `n.0` as `0`)
isFloat(1) //=> false
isFloat(1.0) //=> false
isFloat(NaN) //=> false
isFloat(Infinity) //=> false

Parameters

Optional value: any

The value to test.

Returns boolean

true if value is a float, else returns false.

Const isInteger

isInteger(value?: any): boolean

Returns true if value is an integer, else returns false.

memberof

core

since

0.1.0

see

isFloat

example

// Integer values.
isInteger(-1) //=> true
isInteger(0) //=> true
isInteger(0.0) //=> true (since JS treats `n.0` as `0`)
isInteger(1) //=> true
isInteger(1.0) //=> true

// Non-Integer values.
isInteger() //=> false
isInteger(undefined) //=> false
isInteger(null) //=> false
isInteger([]) //=> false
isInteger([1, '2', 3]) //=> false
isInteger({}) //=> false
isInteger({ a: 1, b: '2', c: 3 }) //=> false
isInteger('') //=> false
isInteger('foo bar baz') //=> false
isInteger(true) //=> false
isInteger(false) //=> false
isInteger(-1.1) //=> false
isInteger(1.1) //=> false
isInteger(NaN) //=> false
isInteger(Infinity) //=> false

Parameters

Optional value: any

The value to test.

Returns boolean

true if value is an integer, else returns false.

Const max

max(values: number[]): number

Returns largest number in values.

throws

values cannot be empty.

memberof

core

since

0.1.0

example

// Integers.
max([]) //=> Error
max([1, 2, 3]) //=> 3

// Floats.
max([1, 1.1]) //=> 1.1
max([1.1, 2.1]) //=> 2.1
max([-1.1, 1.1]) //=> -1.1
max([-1.1, -2.1]) //=> -1.1

Parameters

values: number[]

Returns number

value maxed by 1.

Const maxBy

maxBy<T>(mapper: (value: T) => number): (values: T[]) => number

Similar to max but maps elements in values to values that are used to determine the largest number.
throws

values cannot be empty.

memberof

core

since

0.1.0

see

max

example
```
// Integers.
const data = [{ value: 1 }, { value: 2 }];
const getValue = (o: typeof data[number]  ) => o.value;

maxBy(getValue)([]) //=> Error
maxBy(getValue)(data) //=> 2
```
Type parameters
- T
Parameters
- mapper: (value: T) => number
  
  Function that returns a value to compare.
  - - (value: T): number
    - Parameters
      - value: T
      Returns number
Returns (values: T[]) => number

The largest number.
- - (values: T[]): number
  - Parameters
    - values: T[]
      
      List of items to map before determining the max.
    Returns number

Const sum

sum(numbers: number[]): number

Returns the sum of numbers.
memberof

core

since

1.0.0

example
```
sum([]) //=> 0
sum([0]) //=> 0
sum([1]) //=> 1
sum([1, 2, 3]) //=> 6
sum([1, -2, 3]) //=> 2
```
Parameters
- numbers: number[]
  
  Numbers to sum.
Returns number

Sum of numbers.

Object Functions

Const defaultToValue

defaultToValue<TDefaultValue>(defaultValue?: TDefaultValue): <TValue>(value?: Record<string, TValue>) => Record<string, TValue>

Finally returns value where missing keys will return defaultValue.

Useful to ensure an object always return a default value (rather than undefined) for a key that it does not contain:
example
```
const actions = {
 create: 'CREATE',
 fetch: 'FETCH',
};
const defaultAction = actions.fetch;
const defaultToFetch = defaultToValue(defaultAction);
const defaultedActions = defaultToFetch(actions);
defaultedActions.foo; //=> 'FETCH'
```
memberof

core

since

0.1.0

example
```
defaultToValue()()['qux'] //=> undefined
defaultToValue('foo')({})['qux'] //=> 'foo'
defaultToValue('foo')({ a: 1, b: '2' })['qux'] //=> 'foo'
defaultToValue('foo')({ a: 1, b: '2' })['b'] //=> '2'
```
Type parameters
- TDefaultValue
Parameters
- Optional defaultValue: TDefaultValue
 
 The default value to return when value does not contain a key (optional, defaults to undefined).
Returns <TValue>(value?: Record<string, TValue>) => Record<string, TValue>

value where missing keys will return defaultValue.
- - <TValue>(value?: Record<string, TValue>): Record<string, TValue>
 - Type parameters
 - TValue
 Parameters
 - value: Record<string, TValue> = {}
 
 The object to apply a default value to (optional, defaults to {}).
 Returns Record<string, TValue>

Const delimitKeys

delimitKeys(delimiter?: string): <TValue>(value?: Record<string, TValue>) => string

Finally returns a string containing all values' keys delimited by delimiter.
memberof

core

since

0.1.0

see

delimitValues keys

example
```
delimitKeys()({}) //=> ''
delimitKeys()({ a: 1, b: 2, c: 3 }) //=> 'a,b,c'
delimitKeys('FOO')({ a: 1, b: 2, c: 3 }) //=> 'aFOObFOOc'
```
Parameters
- delimiter: string = ','
 
 String to delimit keys (optional, defaults to ,).
Returns <TValue>(value?: Record<string, TValue>) => string

Finally returns a string containing all values' keys delimited by delimiter.
- - <TValue>(value?: Record<string, TValue>): string
 - Type parameters
 - TValue
 Parameters
 - value: Record<string, TValue> = {}
 
 Object with keys to delimit.
 Returns string

Const delimitValues

delimitValues(delimiter?: string): <TValue>(objectValue?: Record<string, TValue>) => string

Finally returns a string containing all objectValues' values delimited by delimiter.
memberof

core

since

0.1.0

see

delimitKeys values

example
```
delimitValues()({}) //=> ''
delimitValues()({ a: 1, b: 2, c: 3 }) //=> '1,2,3'
delimitValues('FOO')({ a: 1, b: 2, c: 3 }) //=> '1FOO2FOO3'
```
Parameters
- delimiter: string = ','
 
 String to delimit values (optional, defaults to ,).
Returns <TValue>(objectValue?: Record<string, TValue>) => string

Finally returns a string containing all objectValues' values delimited by delimiter.
- - <TValue>(objectValue?: Record<string, TValue>): string
 - Type parameters
 - TValue
 Parameters
 - objectValue: Record<string, TValue> = {}
 Returns string

Const entries

entries<T>(value?: Record<string, T>): [string, T][]

Returns value's entries as a 2D array containing entry arrays where an entry array is a 2 value tuple containing an entry's key and value.
memberof

core

since

0.1.0

see

entriesCount entriesCountIsAny entriesCountIsNone keys values

example
```
 entries(); //=> []
 entries({}); //=> []
 entries({ a: 1, b: 2, c: 3 }); //=> [['a', 1], ['b', 2], ['c', 3]]
```
Type parameters
- T
Parameters
- Optional value: Record<string, T>
 
 object to get entries from.
Returns [string, T][]

Returns value's entries as a 2D array containing entry arrays (i.e., [['key', 'value'], ...]).

Const entriesCount

entriesCount(value?: Record<string, unknown>): number

Returns the number of entries in value.
memberof

core

since

0.1.0

see

count entries keys values

example
```
 entriesCount(); //=> 0
 entriesCount({}); //=> 0
 entriesCount({ a: 1, b: 2, c: 3 }); //=> 3
```
Parameters
- Optional value: Record<string, unknown>
 
 object with entries to count.
Returns number

number of entries in value.

Const entriesCountIsAny

entriesCountIsAny(value?: Record<string, unknown>): boolean

Returns true if value has 1 or more entries, else returns false.
memberof

core

since

0.1.0

see

entriesCount entriesCountIsNone

example
```
 entriesCountIsAny(); //=> false
 entriesCountIsAny({}); //=> false
 entriesCountIsAny({ a: 1, b: 2, c: 3 }); //=> true
```
Parameters
- Optional value: Record<string, unknown>
 
 object with entries to count.
Returns boolean

true if value has 1 or more entries, else returns false.

Const entriesCountIsNone

entriesCountIsNone(value?: Record<string, unknown>): boolean

Inverse of entriesCountIsAny, i.e., returns true if value has 0 entries, else returns false.
memberof

core

since

0.1.0

see

entriesCount entriesCountIsAny

example
```
 entriesCountIsNone(); //=> true
 entriesCountIsNone({}); //=> true
 entriesCountIsNone({ a: 1, b: 2, c: 3 }); //=> false
```
Parameters
- Optional value: Record<string, unknown>
 
 object with entries to count.
Returns boolean

true if value has 0 entries, else returns false.

Const filterEntries

filterEntries<TValue>(predicate?: (value: TValue, key: string) => boolean): (value: Record<string, TValue>) => Record<string, unknown>

Finally returns value with entries kept when optional predicate returns true.
memberof

core

since

0.1.0

see

entries filter mapEntries

example
```
filterEntries()({}) //=> {}
const isEvenNumber = (value: number) => value % 2 === 0;
filterEntries(isEvenNumber)({}) //=> {}
filterEntries(isEvenNumber)({ a: 1, b: 2, c: 3 }) //=> { b: 2 }
```
Type parameters
- TValue
Parameters
- predicate: (value: TValue, key: string) => boolean = ...
 
 Returns true to keep an entry else the entry is omitted from the. returned object (optional, defaults to keep entries). omitted from the returned object..
 - - (value: TValue, key: string): boolean
 - Parameters
 - value: TValue
 - key: string
 Returns boolean
Returns (value: Record<string, TValue>) => Record<string, unknown>

Finally returns an object containing value's filtered entries.
- - (value: Record<string, TValue>): Record<string, unknown>
 - Parameters
 - value: Record<string, TValue>
 
 The object with entries to filter.
 Returns Record<string, unknown>

Const includesKeys

includesKeys(...elements: any[]): <T>(value: Record<string, T>) => boolean

Finally returns true if value's keys includes all elements, else returns false.
memberof

core

since

0.1.0

see

keys includes includesValues

example
```
includesKeys()({}) //=> false
includesKeys('a')({}) //=> false
includesKeys('d')({ a: 1, b: 2, c: 3 }) //=> false
includesKeys('a')({ a: 1, b: 2, c: 3 }) //=> true
includesKeys('a', 'b')({ a: 1, b: 2, c: 3 }) //=> true
```
Parameters
- Rest ...elements: any[]
 
 string array of elements representing keys to check for.
Returns <T>(value: Record<string, T>) => boolean

Finally returns true if value's keys includes all elements, else returns false.
- - <T>(value: Record<string, T>): boolean
 - Type parameters
 - T
 Parameters
 - value: Record<string, T>
 
 object with entries to test.
 Returns boolean

Const includesValues

includesValues(...elements: any[]): <T>(value: Record<string, T>) => boolean

Finally returns true if value's values includes all elements, else returns false.
memberof

core

since

0.1.0

see

includes includesValues values

example
```
includesValues()({}) //=> false
includesValues(1)({}) //=> false
includesValues(4)({ a: 1, b: 2, c: 3 }) //=> false
includesValues(1)({ a: 1, b: 2, c: 3 }) //=> true
includesValues(1, 2)({ a: 1, b: 2, c: 3 }) //=> true
includesValues(1, '2')({ a: 1, b: '2', c: 3 }) //=> true
```
Parameters
- Rest ...elements: any[]
 
 string array of elements representing values to check for.
Returns <T>(value: Record<string, T>) => boolean

Finally returns true if value's values includes all elements, else returns false.
- - <T>(value: Record<string, T>): boolean
 - Type parameters
 - T
 Parameters
 - value: Record<string, T>
 
 object with entries to test.
 Returns boolean

Const injectKeys

injectKeys<TValue>(keys?: string[], defaultValue?: TValue): (valueObject: Record<string, TValue>) => Record<string, TValue>

Finally returns valueObject with all keys (optional, defaults to []) injected as entries with a value of defaultValue (optional, defaults to undefined).
memberof

core

since

0.1.0

see

injectKeys pickKeys

example
```
injectKeys()({}) //=> {}
injectKeys(['b', 'c'])({ a: 1 }) //=> { a: 1, b: undefined, c: undefined }
injectKeys(['b', 'c'], 2)({ a: 1 }) //=> { a: 1, b: 2, c: 2 }
```
Type parameters
- TValue
Parameters
- keys: string[] = []
 
 String array of keys to inject (optional, defaults to []).
- Optional defaultValue: TValue
 
 The default value of injected entries (optional, defaults to undefined).
Returns (valueObject: Record<string, TValue>) => Record<string, TValue>

Finally returns valueObject with all keys injected as entries with a value of defaultValue.
- - (valueObject: Record<string, TValue>): Record<string, TValue>
 - Parameters
 - valueObject: Record<string, TValue>
 
 The object to inject keys into.
 Returns Record<string, TValue>

Const injectMissingKeys

injectMissingKeys<TValue>(keys?: string[], defaultValue?: TValue): (valueObject: Record<string, TValue>) => Record<string, TValue>

Finally returns valueObject with keys (optional, defaults to []) that were missing injected as entries with a value of defaultValue (optional, defaults to undefined).
memberof

core

since

0.1.0

see

injectKeys

example
```
injectMissingKeys()({}) //=> {}
injectMissingKeys(['b', 'c'])({ a: 1 }) //=> { a: 1, b: undefined, c: undefined }
injectMissingKeys(['b', 'c'], 2)({ a: 1 }) //=> { a: 1, b: 2, c: 2 }
```
Type parameters
- TValue
Parameters
- keys: string[] = []
 
 String array of keys to inject (optional, defaults to []).
- Optional defaultValue: TValue
 
 The default value of injected entries (optional, defaults to undefined).
Returns (valueObject: Record<string, TValue>) => Record<string, TValue>

Finally returns valueObject with missing keys injected as entries with a value of defaultValue.
- - (valueObject: Record<string, TValue>): Record<string, TValue>
 - Parameters
 - valueObject: Record<string, TValue>
 
 The object to inject keys into.
 Returns Record<string, TValue>

Const invertEntries

invertEntries<TValue>(value?: Record<string, TValue>): Record<string, TValue>

Finally returns value with the keys and values of entries inverted.
memberof

core

since

0.1.0

example
```
invertEntries() //=> {}
invertEntries({}) //=> {}
invertEntries({ a: 'foo', b: 2, c: 'bar }) //=> { foo: 'a', '2': 'b', bar: 'c' }
```
Type parameters
- TValue
Parameters
- value: Record<string, TValue> = {}
 
 The object with entries to invert (optional, defaults to {}).
Returns Record<string, TValue>

Finally returns an object containing entries of both value1 & value2.

Const isObject

isObject(value: any): boolean

Returns true if value is an object, else returns false.

memberof

core

since

0.1.0

see

isArray

example

// Object values.
isObject({}); //=> true
isObject({ a: 1, b: 2, c: 3 }); //=> true
isObject({ a: 1, b: 2, c: 3 } as Record<string, number>); //=> true

// Non-object values.
 isObject(); //=> false
 isObject(undefined); //=> false
 isObject(null); //=> false
 isObject([]); //=> false
 isObject([1, 2, 3]); //=> false
 isObject('foo bar baz'); //=> false
 [-1, 0, 1].map(isObject); //=> [false, false, false]
 [true, false].map(isObject); //=> [false, false]

Parameters

value: any

object to test.

Returns boolean

true if value is an object, else returns false

Const keys

keys(value?: Record<string, unknown>): string[]

Returns a string array of value's keys.
memberof

core

since

0.1.0

see

values

example
```
keys(); //=> []
keys({}); //=> []
keys({ a: 1, b: 2, c: 3 }); //=> ['a', 'b', 'c']
```
Parameters
- Optional value: Record<string, unknown>
 
 object with keys to use.
Returns string[]

Returns a string array of value's keys

Const mapEntries

mapEntries<TValue, TMapped>(options?: MapEntriesOptions<TValue, TMapped>): (objectValue: Record<string, TValue>) => Record<string, TMapped>

Finally returns objectValue with all entries mapped using optional MapEntriesOptions to provide new keys and values.

memberof

core

since

0.1.0

see

entries map reduceEntries

example

const appendFoo = (__: number, k: string) => k + 'Foo';
mapEntries()({}) //=> {}
mapEntries({ keyMapper: appendFoo })({}) //=> {}
mapEntries({ keyMapper: appendFoo })({ a: 1, b: 2, c: 3 }) //=> { aFoo: 1, bFoo: 2, cFoo: 3 }
const doubleNumber = (v: number) => v * 2;
mapEntries({ valueMapper: doubleNumber })({ a: 1, b: 2, c: 3 }) //=> { a: 2, b: 4, c: 6 }
const isEvenNumber = (value: number) => value % 2 === 0;
mapEntries({ keepEntry: isEvenNumber })({ a: 1, b: 2, c: 3 }) //=> { b: 2 }

Type parameters

TValue
TMapped

Parameters

options: MapEntriesOptions<TValue, TMapped> = {}

Returns (objectValue: Record<string, TValue>) => Record<string, TMapped>

Finally returns an object containing objectValue's mapped entries.

- (objectValue: Record<string, TValue>): Record<string, TMapped>
- Parameters
 - objectValue: Record<string, TValue>
 
 The object with entries to map.
 Returns Record<string, TMapped>

Const mapKeys

mapKeys<TValue>(transformer?: (__: TValue, key: string) => string): (objectValue: Record<string, TValue>) => Record<string, unknown>

Finally returns objectValue with the keys of all entries mapped using optional transformer.
memberof

core

since

0.1.0

see

keys mapEntries mapValues

example
```
const appendFoo = (__: number, k: string) => k + 'Foo';
mapKeys()({}) //=> {}
mapKeys(appendFoo)({}) //=> {}
mapKeys(appendFoo)({ a: 1, b: 2, c: 3 }) //=> { aFoo: 1, bFoo: 2, cFoo: 3 }
```
Type parameters
- TValue
Parameters
- transformer: (__: TValue, key: string) => string = ...
 
 Returns the next key (optional, defaults to return the original key).
 - - (__: TValue, key: string): string
 - Parameters
 - __: TValue
 - key: string
 Returns string
Returns (objectValue: Record<string, TValue>) => Record<string, unknown>

Finally returns an object containing objectValue's mapped entries.
- - (objectValue: Record<string, TValue>): Record<string, unknown>
 - Parameters
 - objectValue: Record<string, TValue>
 
 The object with entries keys to map.
 Returns Record<string, unknown>

Const mapValues

mapValues<TValue>(transformer?: (value: TValue, __: string) => TValue): (objectValue: Record<string, TValue>) => Record<string, TValue>

Finally returns objectValue with the values of all entries mapped using optional transformer.
memberof

core

since

0.1.0

see

mapEntries mapKeys values

example
```
const doubleNumber = (v: number) => v * 2;
mapValues()({}) //=> {}
mapValues(doubleNumber)({}) //=> {}
mapValues(doubleNumber)({ a: 1, b: 2, c: 3 }) //=> { a: 2, b: 4, c: 6 }
```
Type parameters
- TValue
Parameters
- transformer: (value: TValue, __: string) => TValue = ...
 
 Returns the next value (optional, defaults to return the original value).
 - - (value: TValue, __: string): TValue
 - Parameters
 - value: TValue
 - __: string
 Returns TValue
Returns (objectValue: Record<string, TValue>) => Record<string, TValue>

Finally returns an object containing objectValue's mapped entries.
- - (objectValue: Record<string, TValue>): Record<string, TValue>
 - Parameters
 - objectValue: Record<string, TValue>
 
 The object with entries values to map.
 Returns Record<string, TValue>

Const mergeEntries

mergeEntries<TValue1>(value1?: Record<string, TValue1>): <TValue2>(value2?: Record<string, TValue2>) => {}

Finally returns an object containing all elements in both value1 & value2 where entries with identical keys will be entries from value2.
memberof

core

since

0.1.0

see

concat union

example
```
mergeEntries()() //=> {}
mergeEntries({})({}) //=> {}
mergeEntries({ a: 1, b: 2 })({ c: 3, d: 4 }) //=> { a: 1, b: 2, c: 3, d: 4 }
mergeEntries({ a: 1, b: 2 })({ a: 1, b: 3 }) //=> { a: 1, b: 3 }
mergeEntries({ a: 1, b: 2 })({}) //=> { a: 1, b: 3 }
mergeEntries({})({ c: 3, d: 4 }) //=> { c: 3, d: 4 }
```
Type parameters
- TValue1
Parameters
- value1: Record<string, TValue1> = {}
 
 The first object to merge.
Returns <TValue2>(value2?: Record<string, TValue2>) => {}

Finally returns an object containing entries of both value1 & value2.
- - <TValue2>(value2?: Record<string, TValue2>): {}
 - Type parameters
 - TValue2
 Parameters
 - value2: Record<string, TValue2> = {}
 
 The second object to merge.
 Returns {}

Const objectOr

objectOr(defaultValue?: Record<string, unknown>): (value: any) => Record<string, unknown>

Finally returns value if it is valid via isObject, else returns defaultValue.
memberof

core

since

0.1.0

see

valueIf

example
```
objectOr()(null); //=> {} as Record<string, unknown>
objectOr({ a: 1 })(null); //=> { a: 1 }
objectOr({ a: 1 })({ a: 1, b: 2, c: 3 }); //=> { a: 1, b: 2, c: 3 }
```
Parameters
- defaultValue: Record<string, unknown> = {}
 
 The default value to return (optional, defaults to Record<string, unknown>).
Returns (value: any) => Record<string, unknown>

Finally returns value if it is valid via isObject, else returns defaultValue
- - (value: any): Record<string, unknown>
 - Parameters
 - value: any
 
 Value to test.
 Returns Record<string, unknown>

Const objectToString

objectToString<TValue>(value: Record<string, TValue>, indentSpaces?: number): string

Returns value as a string.
memberof

core

since

0.1.0

example
```
objectToString({}) //=> '{}'
objectToString({ a: 1, b: '2', c: 3}) //=> '{"a":1,"b":"2","c":3}'
```
Type parameters
- TValue
Parameters
- value: Record<string, TValue>
 
 Object to convert to string.
- indentSpaces: number = 0
 
 Optional number of spaces to indent the object (defaults to 0, i.e., no spacing).
Returns string

value as a string.

Const omitKeys

omitKeys<TValue>(...keys: string[]): (value: Record<string, TValue>) => Record<string, unknown>

Finally returns value where entries with a key included in keys are omited.
memberof

core

since

0.1.0

see

filterEntries

example
```
omitKeys()({}) //=> {}
omitKeys('a', 'b')({}) //=> {}
omitKeys('a', 'b)({ a: 1, b: 2, c: 3 }) //=> { c: 3 }
omitKeys('d')({ a: 1, b: 2, c: 3 }) //=> { a: 1, b: 2, c: 3 }
```
Type parameters
- TValue
Parameters
- Rest ...keys: string[]
 
 string array of keys to omit.
Returns (value: Record<string, TValue>) => Record<string, unknown>

Finally returns value where entries with a key included in keys are omited.
- - (value: Record<string, TValue>): Record<string, unknown>
 - Parameters
 - value: Record<string, TValue>
 
 The object with keys to filter.
 Returns Record<string, unknown>

Const pickKeys

pickKeys<TValue>(...keys: string[]): (value: Record<string, TValue>) => Record<string, unknown>

Inverse of omitKeys, i.e., finally returns value where entries have a key included in keys.
memberof

core

since

0.1.0

see

omitKeys

example
```
pickKeys()({}) //=> {}
pickKeys('a', 'b')({}) //=> {}
pickKeys('a', 'b)({ a: 1, b: 2, c: 3 }) //=> { a: 1, b: 2 }
pickKeys('d')({ a: 1, b: 2, c: 3 }) //=> {}
```
Type parameters
- TValue
Parameters
- Rest ...keys: string[]
 
 String array of keys to pick.
Returns (value: Record<string, TValue>) => Record<string, unknown>

Finally returns an object containing value's entries with keys that are included in keys.
- - (value: Record<string, TValue>): Record<string, unknown>
 - Parameters
 - value: Record<string, TValue>
 
 The object with keys to pick.
 Returns Record<string, unknown>

Const pluckKey

pluckKey<TValue>(key: string): (valueObject: Record<string, TValue>) => TValue

Finally returns the value at key in objectValue if found, else returns undefined.

Intended for curried usage hence pluckKey accepts a key to generate a "plucking" function that will finally return the value of objectValue at key:
example
```
const values = [{ name: 'foo' }, { name: 'bar' }, { name: 'baz' }];
const pluckName = pluckKey('name');
values.map(pluckName); //=> ['foo', 'bar', 'baz']
```
memberof

core

since

0.1.0

see

pluckKeys pickKeys

example
```
pluckKey('a')({}) //=> undefined
pluckKey('a')({ a: 1, b: 2, c: 3 }) //=> 1
pluckKey('d')({ a: 1, b: 2, c: 3 }) //=> undefined
```
Type parameters
- TValue
Parameters
- key: string
 
 String to pluck.
Returns (valueObject: Record<string, TValue>) => TValue

Finally returns the value at key in objectValue.
- - (valueObject: Record<string, TValue>): TValue
 - Parameters
 - valueObject: Record<string, TValue>
 
 The object with keys to pluck.
 Returns TValue

Const pluckKeys

pluckKeys<TValue>(key: string): (values: Record<string, TValue>[]) => TValue[]

Applies pluckKey to an array of objects, i.e., returns the value at key for all objects in values. Serves as a convenient alternative to mapping pluckKey over an array of objects.

Similar to pluckKey, pluckKeys is intended for curried usage hence accepts a key to generate a "plucking" function that will finally return the values at key in all objects in values:
example
```
const values = [{ name: 'foo' }, { name: 'bar' }, { name: 'baz' }];
const pluckNames = pluckKeys('name');
pluckNames(values); //=> ['foo', 'bar', 'baz']
```
memberof

core

since

0.1.0

see

pluckKey

example
```
pluckKeys('name')([]) //=> []
pluckKeys('name')([{}]) //=> [undefined]
pluckKeys('name')([{ name: 'foo' }, { name: 'bar' }, { name: 'baz' }]) //=> ['foo', 'bar', 'baz']
pluckKeys('qux')([{ name: 'foo' }, { name: 'bar' }, { name: 'baz' }]) //=> [undefined, undefined, undefined]
```
Type parameters
- TValue
Parameters
- key: string
 
 String to pluck.
Returns (values: Record<string, TValue>[]) => TValue[]

An array of values at key in all objects in values.
- - (values: Record<string, TValue>[]): TValue[]
 - Parameters
 - values: Record<string, TValue>[]
 
 Array of objects with keys to pluck.
 Returns TValue[]

Const reduceEntries

reduceEntries<TMapped>(initial?: TMapped, transformer?: (previousValue: TMapped, value: any, key: string) => TMapped, includeNested?: boolean): (objectValue: Record<string, any>) => TMapped

Finally returns objectValue's entries reduced to a single value using initial as the starting value and transformer to provide the next value.

Nested objects can optionally be reduced if includeNested is true, else only the root object objectValue is reduced.
memberof

core

since

0.1.0

see

entries map mapEntries reduce

example
```
reduceEntries()({}) //=> {}
const concatKeys = (prev: string, __: number, key: string) => prev + key;
reduceEntries('', concatKeys)({}) //=> ''
reduceEntries('', concatKeys)({ a: 1, b: 2, c: 3 }) //=> 'abc'
const sumNumbers = (prev: number, value: number) => prev + value;
reduceEntries(0, sumNumbers)({ a: 1, b: 2, c: 3 }) //=> 6

// Reduce values of nested objects.
reduceEntries(0, sumNumbers, true)({ a: 1, first: { b: 2, second: { c: 3 } } }) //=> 6
```
Type parameters
- TMapped
Parameters
- initial: TMapped = ...
 
 The first value of prev passed to the transformer.
- transformer: (previousValue: TMapped, value: any, key: string) => TMapped = ...
 
 Returns the next value (optional, defaults to return the original value).
 - - (previousValue: TMapped, value: any, key: string): TMapped
 - Parameters
 - previousValue: TMapped
 - value: any
 - key: string
 Returns TMapped
- includeNested: boolean = false
 
 Optional (defaults to false) boolea, if true, nested objects are reduced using transformer, else only the root object objectValue is reduced.
Returns (objectValue: Record<string, any>) => TMapped

An object containing objectValue's mapped entries.
- - (objectValue: Record<string, any>): TMapped
 - Parameters
 - objectValue: Record<string, any>
 
 The object with entries to reduce.
 Returns TMapped

Const values

values<T>(value?: Record<string, T>): T[]

Returns an array of value's values.
memberof

core

since

0.1.0

see

keys

example
```
 values(); //=> []
 values({}); //=> []
 values({ a: 1, b: 2, c: 3 }); //=> [1, 2, 3]
```
Type parameters
- T
Parameters
- Optional value: Record<string, T>
 
 object with values.
Returns T[]

Returns an array of value's values.

Other Functions

Const toggleStrings

toggleStrings(toggleMap: Record<string, boolean>, delimiter?: string): (preserved: string) => string

Convenience method for generating strings with conditional sub-strings. Appends delimited muxMap keys that have a true value to verbatimStr.
memberof

core

since

1.0.0

example
```
toggleStrings({})('') //=> ''
toggleStrings({})('foo bar') //=> 'foo bar'
toggleStrings({ baz: true, qux: true })('foo bar') //=> 'foo bar baz qux'
toggleStrings({ baz: false, qux: false })('foo bar') //=> 'foo bar'

// Delimiter.
toggleStrings({ baz: true, qux: true }, '-')('foo bar') //=> 'foo bar-baz-qux'
```
Parameters
- toggleMap: Record<string, boolean>
- delimiter: string = ' '
 
 Delimits appended strings (optional, defaults to ' ').
Returns (preserved: string) => string

Finally returns a string containing the verbatimStr appended with the delimited keys of entries in stringsToToggleMap that have a true value.
- - (preserved: string): string
 - Parameters
 - preserved: string
 Returns string

Promise Functions

Const allSettled

allSettled<T>(promises: Promise<T>[]): Promise<ResolvedPromise<T>[]>

Returns an array of Promise<ResolvedPromise> when all promises have resolved to either fulfilled or rejected.

Serves as a functional polyfilled alternative to Promise.allSettled hence is useful regardless of older browsers/runtimes when running several Promises & operating on their resolved data:

example

const fetchUsers = page => Math.random() > 0.5 // Simulate potential error.
    ? Promise.resolve([])
    : new Promise((__, reject) => setTimeout(reject, 1000));
const fetchUserData = async () => {
    // Run all promises regardless of resolved status.
    const resolved = await allSettled(pageNumbers.map(fetchUsers(1), fetchUsers(2)));
    // Omit rejected `Promises`.
    const fulfilled = resolved.filter(v => v.status === 'fulfilled');
    const users = fulfilled.map(v => v.value);
};

memberof

core

since

0.1.0

see

allSettledFilterStatus

example

await allSettled([Promise.resolve(1), Promise.reject(2)]); //=> [{ status: 'fulfilled', value: 1 }, { status: 'rejected', value: 2 }]

Type parameters

Parameters

promises: Promise<T>[]

Promises to run.

Returns Promise<ResolvedPromise<T>[]>

An array of Promise<ResolvedPromise> when all promises have resolved to either fulfilled or rejected.

Const allSettledFilterStatus

allSettledFilterStatus(status?: ResolvedPromiseStatus): <T>(promises: Promise<T>[]) => Promise<ResolvedPromise<T>[]>

Finally returns a filtered array of ResolvedPromise where all ResolvedPromise.status are status.

Serves as a convenient alternative to collecting resolved Promises from allSettled with a specific resolved status:

example

const fetchUsers = page => Math.random() > 0.5 // Simulate potential error.
    ? Promise.resolve([])
    : new Promise((__, reject) => setTimeout(reject, 1000));
const fetchUserData = async () => {
    pendingPromises = pageNumbers.map(fetchUsers(1), fetchUsers(2));
    // Collect all fulfilled promises.
    const fulfilled = await allSettledFilterStatus('fulfilled')(pendingPromises);
    const users = fulfilled.map(v => v.value);
};

memberof

core

since

0.1.0

see

allSettled

example

const pendingPromises = [Promise.resolve(1), Promise.reject(2)];
await allSettledFilterStatus()(pendingPromises); //=> [{ status: 'fulfilled', value: 1 }]
await allSettledFilterStatus('fulfilled')(pendingPromises); //=> [{ status: 'fulfilled', value: 1 }]
await allSettledFilterStatus('rejected')(pendingPromises); //=> [{ status: 'rejected', value: 2 }]

Parameters

status: ResolvedPromiseStatus = ...

String to filter ResolvedPromises by (optional, defaults to fulfilled).

Returns <T>(promises: Promise<T>[]) => Promise<ResolvedPromise<T>[]>

Finally returns a filtered array of ResolvedPromise where all ResolvedPromise.status are status.

- <T>(promises: Promise<T>[]): Promise<ResolvedPromise<T>[]>
- Type parameters
 - T
 Parameters
 - promises: Promise<T>[]
 
 Promises to run.
 Returns Promise<ResolvedPromise<T>[]>

Const delayFor

delayFor(delayMs?: number): Promise<unknown>

Returns a Promise resolving to delayMs after waiting for delayMs milliseconds.

Useful for pausing asynchronous operations for a specific duration:
example
```
const delayedLogNumbers = async numbers =>
 numbers.forEach(async n => {
 await delayFor(2000);
 console.log(n); // Log `n` after `2000`ms
 });
```
memberof

core

since

0.1.0

see

opRuntime

example
```
await delayFor(); //=> (pauses async operations for `1000`ms)
await delayFor(2000); //=> (pauses async operations for `2000`ms)
```
Parameters
- delayMs: number = 1000
 
 Number of milliseconds to delay (optional, defaults to 1000ms)
Returns Promise<unknown>

A Promise resolving to delayMs after waiting for delayMs milliseconds.

Const promiseAll

promiseAll<TPoolResults>(poolSize?: number, onPoolComplete?: (poolResults: TPoolResults[]) => void): <T>(promises: Promise<T>[]) => Promise<T[]>

Concurrency-controlled alternative to Promise.all. I.e., finally returns a Promise containing an array of Promise values by asynchronously running promises via a Promise pool where concurrency is limited to poolSize, and each pool iteration's results are reactable via onPoolComplete.

Useful when asynchronously running several Promises in parallel with controlled concurrency:
example
```
// Simulate collecting a page as a number.
const fetchPages = n => new Promise(r => setTimeout(() => r(n), n));

let pages = [];
const onPoolComplete = (poolPages: number) => pages = [...pages, ...poolPages];
const poolSize = 2;
const pendingPromises = [fetchPages(100), fetchPages(200), fetchPages(300), fetchPages(400)];
await promiseAll(poolSize, onPoolComplete)(pendingPromises);
pages //=> [[100,200], [300, 400]]
```
memberof

core

since

0.1.0

see

promiseAllProgress promiseSequence

example
```
let results = [];
const onPoolComplete = results => results = [..results, results];
const delayedWork = duration => new Promise(r => setTimeout(() => r(duration), duration));
const pendingPromises = [delayedWork(100), delayedWork(200), delayedWork(300), delayedWork(400)];

await promiseAll(onPoolComplete)(pendingPromises); // `Infinite` concurrency.
results; //=> [100, 200, 300, 400]

results = []; // Reset `results`.
await promiseAll(onPoolComplete, 2)(pendingPromises); // Concurrency `2`.
results //=> [[100, 200], [300, 400]]
```
Type parameters
- TPoolResults
Parameters
- poolSize: number = ...
 
 Number of promises to run per pool iteration (optional, defaults to Infinity).
- onPoolComplete: (poolResults: TPoolResults[]) => void = ...
 
 Called when results are collected from running a Promise pool (optional, defaults to return undefined).
 - - (poolResults: TPoolResults[]): void
 - Parameters
 - poolResults: TPoolResults[]
 Returns void
Returns <T>(promises: Promise<T>[]) => Promise<T[]>

Finally returns a Promise containing an array of Promise values.
- - <T>(promises: Promise<T>[]): Promise<T[]>
 - Type parameters
 - T
 Parameters
 - promises: Promise<T>[]
 
 Promises to run.
 Returns Promise<T[]>

Const promiseAllProgress

promiseAllProgress<T>(onProgress?: PromiseAllProgressFunction<T>): (promises: Promise<T>[]) => Promise<T[]>

Convenient alternative to Promise.all that runs all promises (calling onProgress when each Promise resolves) before finally returning an array of Promises.

Useful when responding to the completion of each Promise:

example

const updateLoadingBar = percent => {
    // ...update loading bar.
};
const fetchUser = id => new Promise(r => setTimeout(() => r('user ' + id), 1000));
const onProgress = (percentComplete, value) => updateLoadingBar(percentComplete);
const pendingUsers = [fetchUser(1), fetchUser(2), fetchUser(3), fetchUser(4)];
// Fetch users & update loading bar as users are fetched.
const users = promiseAllProgress(onProgress)(pendingUsers);

memberof

core

since

0.1.0

example

let percentages = [];
const onProgress = (percentage, value) => [...percentages, { percentage, value }];
const delayedWork = duration => new Promise(r => setTimeout(() => r(duration), duration));
const pendingPromises = [delayedWork(1000), delayedWork(2000)];
await promiseAllProgress(onProgress)(pendingPromises); //=> [1000, 2000]
percentages; //=> [{ percentage: 0, value: 50 }, { percentage: 0, value: 100 }]

Type parameters

Parameters

onProgress: PromiseAllProgressFunction<T> = ...

Called for each resolved Promise.

Returns (promises: Promise<T>[]) => Promise<T[]>

Finally returns an array of Promise<ResolvedPromise> when all promises have resolved to either fulfilled or rejected.

- (promises: Promise<T>[]): Promise<T[]>
- Parameters
 - promises: Promise<T>[]
 
 Promises to run.
 Returns Promise<T[]>

Const promiseFilter

promiseFilter<T>(predicate?: (value: T, index: number) => Promise<boolean>): (array: T[]) => Promise<T[]>

Asynchronous alternative to filter, i.e., finally returns a Promise containing array elements where predicate returns a Promise boolean resolve to true, else elements are omitted.
memberof

core

since

0.1.0

see

filter promiseAll

example
```
const promiseIsEven = n => Promise.resolve(n % 2 === 0);
await promiseFilter(promiseIsEven)([]) //=> []
await promiseFilter(promiseIsEven)([1, 2, 3]) //=> [2]
```
Type parameters
- T
Parameters
- predicate: (value: T, index: number) => Promise<boolean> = ...
 
 Returns a Promise boolean trueto keepvalue, else returns falseto omitvalue`.
 - - (value: T, index: number): Promise<boolean>
 - Parameters
 - value: T
 - index: number
 Returns Promise<boolean>
Returns (array: T[]) => Promise<T[]>

Finally returns a Promise resolving to array elements where predicate returned a Promise resolving to true.
- - (array: T[]): Promise<T[]>
 - Parameters
 - array: T[]
 
 Array to filter.
 Returns Promise<T[]>

Const promiseReduce

promiseReduce<T, TMapped>(initial: TMapped, transformer?: (prevValue: TMapped, value: T) => TMapped): (promises: Promise<T>[]) => Promise<TMapped>

Single-value alternative to promiseSequence. I.e., synchronously runs promises in sequential order using initialValue as the starting value and transformer to provide a new value based on the previous value (i.e., prevValue) for each Promise to finally return a Promise containing the a single value.

Useful when synchronously running several Promises where subsequent Promises may depend on the result of the previous Promise:
example
```
const fetchDelayedString = (duration, s) => new Promise(r => setTimeout(() => r(s), duration));
const initialString = '';
const joinStrings = (prevString, s) => prevString + s;

const pendingPromises = [
 fetchDelayedString(300, 'foo'),
 fetchDelayedString(200, 'bar'),
 fetchDelayedString(100, 'baz')
];
const results = await promiseReduce(initialString, joinStrings)(pendingPromises);
results; //=> 'foobarbaz'
```
memberof

core

since

0.1.0

see

promiseSequence
Type parameters
- T
- TMapped
Parameters
- initial: TMapped
 
 Starting value.
- transformer: (prevValue: TMapped, value: T) => TMapped = ...
 
 Accepts prevValue to return a new value.
 - - (prevValue: TMapped, value: T): TMapped
 - Parameters
 - prevValue: TMapped
 - value: T
 Returns TMapped
Returns (promises: Promise<T>[]) => Promise<TMapped>

Finally returns a Promise containing an array of Promise values.
- - (promises: Promise<T>[]): Promise<TMapped>
 - Parameters
 - promises: Promise<T>[]
 
 Promises to run.
 Returns Promise<TMapped>

Const promiseSequence

promiseSequence<T, TMapped>(promises: Promise<T>[]): Promise<TMapped[]>

Sequential alternative to promiseAll. I.e., synchronously runs promises in sequential order to return a Promise containing an array of values.

Useful when synchronously running several Promises in an ordered sequence:
example
```
const delayedNumber = duration => new Promise(r => setTimeout((duration) => r(duration), duration));
const getLongTask = () => delayedNumber(1000);
const getShortTask = () => delayedNumber(0);

let result = promiseSequence([getLongTask(), getShortTask()]);
// `Promise`s are run in sequence hence `getLongTask` result is first.
result //=> [1000, 0]
```
memberof

core

since

0.1.0

see

promiseAll promiseReduce
Type parameters
- T
- TMapped
Parameters
- promises: Promise<T>[]
 
 Promises to run.
Returns Promise<TMapped[]>

Returns a Promise containing an array of values

Const promiseStatus

promiseStatus<T>(promise: Promise<T>): Promise<PromiseStatusString>

Returns a string representing the promise's statuswhere the string is either'fulfilled', 'rejected', or 'pending'`.
memberof

core

since

0.1.0

example
```
await promiseStatus(Promise.resolve(1)); //=> 'fulfilled'
await promiseStatus(Promise.reject(1)); //=> 'rejected'
await promiseStatus(new Promise(() => undefined); //=> 'pending'
```
Type parameters
- T
Parameters
- promise: Promise<T>
 
 Promise to check.
Returns Promise<PromiseStatusString>

A string representing the promise's status`.

Const promisify

promisify<TValue>(testFunction: AnyFunction): (...args: any[]) => Promise<TValue>

Provides a basic method to convert testFunction into an altered function that returns a Promise, which can finally be called to return testFunction's error or result depending on resolution of its returned Promise.

Useful when updating legacy functions to use Promises:
example
```
const isEven = n => n % 2 === 0;
const delayedIsEven = (n, callback) => setTimeout(
 () => isEven(n) ? callback(undefined, 'is even') : callback('not even')
);

const promisedDelayedIsEven = promisify(delayedIsEven);
await promisedDelayedIsEven(1); //=> 'not even'
await promisedDelayedIsEven(2); //=> 'is even'
```
memberof

core

since

0.1.0
Type parameters
- TValue = any
Parameters
- testFunction: AnyFunction
 
 The legacy non-Promise function that accepts a callback function (i.e., (error, result) => undefined). convert to return a Promise.
Returns (...args: any[]) => Promise<TValue>

testFunction altered to finally return its callback data via a Promise.
- - (...args: any[]): Promise<TValue>
 - Parameters
 - Rest ...args: any[]
 
 The arguments for the original testFunction.
 Returns Promise<TValue>

Const rejectAfter

rejectAfter(timeoutMs?: number, error?: Error): <T>(promise: Promise<T>) => Promise<T>

Finally returns error as a rejected Promise if timeout is exceeded, else returns promise's value.

Useful for running a Promise within a fixed duration:
```
const fetchUsers = () => {
 // ...returns `Promise`.
};
const users;
const timeout = 2000;
try {
 users = rejectAfter(timeout)(fetchUsers()); // Actual value if `timeout` isn't exceeded.
} catch (e) {
 users = []; // Default value if `timeout` exceeded.
}
```
memberof

core

since

0.1.0

see

rejectAllAfter

example
```
await rejectAfter(2000)(async () => setTimeout(r => r('fulfilled'), 1000)); //=> 'fulfilled'
await rejectAfter(2000)(async () => setTimeout(r => r('fulfilled'), 3000)); //=> 'Error'
```
Parameters
- timeoutMs: number = 10000
- error: Error = ...
 
 An Error to return if timeout is exceeded (optional, defaults to a generic Error).
Returns <T>(promise: Promise<T>) => Promise<T>

Finally returns error as a rejected Promise if timeout is exceeded, else returns promise's value.
- - <T>(promise: Promise<T>): Promise<T>
 - Type parameters
 - T
 Parameters
 - promise: Promise<T>
 
 A promise to potentially reject.
 Returns Promise<T>

Const rejectAllAfter

rejectAllAfter(timeoutMs?: number, error?: Error): <T>(promises: Promise<T>[]) => Promise<void | T[]>

Finally returns error as a rejected Promise if timeout is exceeded, else returns an array of values for each Promise in promises.

Useful for running several Promises within a fixed duration:

example

const fetchUsers = () => {
    // ...returns `Promise`.
};
const fetchPages = () => {
    // ...returns `Promise`.
};
const timeout = 2000;
let users;
let pages;
try {
    const promises = [fetchUsers(), fetchPages()];
    // Actual values if all `promises` complete before `timeout`.
    const [fetchedUsers, fetchedPages] = rejectAllAfter(timeout)(promises);
} catch (e) {
   // ...error handling.

    // Default values if `timeout` exceeded.
    users = [];
    pages = [];
}

memberof

core

since

0.1.0

see

rejectAfter

example

const timeout = 2000;
const longRunningTask = async (duration: number) => await new Promise(
    r => setTimeout(() => r('fulfilled'), duration)
);
const tasksBeforeTimeout = [
    longRunningTask(timeout / 2),
    longRunningTask(timeout / 3),
];
const tasksAfterTimeout = [
    longRunningTask(timeout * 2),
    longRunningTask(timeout * 3),
];

await rejectAllAfter(timeout)(tasksBeforeTimeout)); //=> ['fulfilled', 'fulfilled']
await rejectAllAfter(timeout)(tasksAfterTimeout); //=> 'Error'

Parameters

timeoutMs: number = 10000
error: Error = ...

An Error to return if timeout is exceeded (optional, defaults to generic Error).

Returns <T>(promises: Promise<T>[]) => Promise<void | T[]>

Finally returns error as a rejected Promise if timeout is exceeded, else returns an array of values for each Promise in promises

- <T>(promises: Promise<T>[]): Promise<void | T[]>
- Type parameters
 - T
 Parameters
 - promises: Promise<T>[]
 Returns Promise<void | T[]>

String Functions

Const camelCase

camelCase(value: string): string

Returns value in camelCase.

memberof

core

since

0.1.0

see

pascalCase

example

camelCase(''); //=> ''
camelCase('foo'); //=> 'foo'
camelCase('fooBar'); //=> 'fooBar'
camelCase('FOO'); //=> 'foo'
camelCase('foo bar'); //=> 'fooBar'
camelCase('fooBarBazQUX'); //=> 'fooBarBazQux'
camelCase('FooBar'); //=> 'fooBar'
camelCase('--foo-bar'); //=> 'fooBar'
camelCase('__FOO_BAR__'); //=> 'fooBar'

Parameters

value: string

string to alter.

Returns string

Returns value in camelCase.

Const constantCase

constantCase(value: string): string

Returns value in 'CONSTANT_CASE'.

memberof

core

since

0.1.0

see

upperCase snakeCase

example

constantCase(''); //=> ''
constantCase('foo'); //=> 'FOO'
constantCase('fooBar'); //=> 'FOO_BAR'
constantCase('FOO'); //=> 'FOO'
constantCase('foo bar'); //=> 'FOO_BAR'
constantCase('fooBarBazQUX'); //=> 'FOO_BAR_BAZ_QUX'
constantCase('FooBar'); //=> 'FOO_BAR'
constantCase('__foo_bar'); //=> 'FOO_BAR'
constantCase('__FOO_BAR__'); //=> 'FOO_BAR'

Parameters

value: string

Array to test.

Returns string

value in 'CONSTANT_CASE'.

Const endsWith

endsWith(target: string): (value: string) => boolean

Finally returns true if 'value' starts with target, else returns false.
memberof

core

since

0.1.0

see

startsWith

example
```
endsWith('')(''); //=> true
endsWith('foo')('foo bar baz'); //=> false
endsWith('bar')('foo bar baz'); //=> false
endsWith('baz')('foo bar baz'); //=> true
endsWith('qux')('foo bar baz'); //=> false
```
Parameters
- target: string
  
  Target string to check for.
Returns (value: string) => boolean

Finally returns true if 'value' starts with target, else returns false.
- - (value: string): boolean
  - Parameters
    - value: string
      
      string to test.
    Returns boolean

Const hexColorToInteger

hexColorToInteger(value: string): number

Returns value as an integer if value contains a valid hexadecimal color string, else throws TypeError.

Valid hexadecimal strings are 7 character strings beginning with #, followed by a hexadecimal number within the range of 000000 to FFFFFF beginning with a # prefix that is follwed by a 6 digit hexadecimal number, e.g., #FFFFFF).
throws

{TypeError} value must be a hex string.

memberof

core

since

0.1.0

see

integerToHexColor isHexColor

example
```
 hexColorToInteger(''); //=> `TypeError`
 hexColorToInteger('foo bar'); //=> `TypeError`
 hexColorToInteger('#00000F'); //=> 15
 hexColorToInteger('foo #00000F bar'); //=> 15
```
Parameters
- value: string
  
  string to convert.
Returns number

value as an integer if value contains a valid hexadecimal color string.

Const initialsCase

initialsCase(value: string): string

Returns value in 'I C' (initials case).

memberof

core

since

0.1.0

see

titleCase

example

initialsCase(''); //=> ''
initialsCase('foo'); //=> 'F'
initialsCase('fooBar'); //=> 'F B'
initialsCase('FOO'); //=> 'F'
initialsCase('foo bar'); //=> 'F B'
initialsCase('fooBarBazQUX'); //=> 'F B B Q'
initialsCase('FooBar'); //=> 'F B'
initialsCase('__foo_bar'); //=> 'F B'
initialsCase('__FOO_BAR__'); //=> 'F B'

Parameters

value: string

string to alter.

Returns string

value in 'I C' (initials case).

Const invertHexColor

invertHexColor(value: string): string

Accepts a valid hex color value & returns it's inverted valid hex color.
memberof

core

since

1.0.0

see

stringToHexColor isHexColor

example
```
invertHexColor() //=> Error
invertHexColor('qux') //=> Error
invertHexColor('#000000') //=> '#FFFFFF'
invertHexColor('#FF0000') //=> '#FF0000'
invertHexColor('#00FF00') //=> '#FF00FF'
```
Parameters
- value: string
  
  valid hex color string to convert to hex color.
Returns string

value as valid hex color.

Const isHexColor

isHexColor(value: string): boolean

Returns true if value is a color hexadecimal color string (via hexColorToInteger) where hexadecimal number is within the range of 000000 to FFFFFF.

memberof

core

since

0.1.0

see

hexColorToInteger

example

 isHexColor(''); //=> false
 isHexColor('foo'); //=> false
 isHexColor('0xFFFFFF'); //=> false
 isHexColor('1'); //=> false
 isHexColor('000000'); //=> false
 isHexColor('#FFF'); //=> false
 isHexColor('#000000'); //=> true
 isHexColor('#FFFFFF'); //=> true
 isHexColor('#FF0000'); //=> true

Parameters

value: string

Value to test.

Returns boolean

true if value is a color hexadecimal color string.

Const isString

isString(value: any): boolean

Returns true if value is a string, else returns false.

memberof

core

since

0.1.0

example

// String values.
isString(''); //=> true
isString('a'); //=> false
isString('abc'); //=> false

// Non-string values.
isString(undefined); //=> false
isString(null); //=> false
isString(true); //=> false
isString(); //=> false
isString(1); //=> false
isString([1]); //=> false
isString({ a: 1 }); //=> false

Parameters

value: any

Value to test.

Returns boolean

true if value is a string, else returns false.

Const joinToArray

joinToArray<TDelimiter>(delimiter: TDelimiter): <TArr>(arr: TArr[]) => (TDelimiter | TArr)[][]

Returns text as an array of numbers where each number is the incrementing number representation of letter characters where space character is considered the 0, 'a' is 1, etc. until 'z' which is 26.
memberof

core

since

1.0.0

example
```
toLetterChars(); //=> Error
toLetterChars(''); //=> ''
toLetterChars('foo bar 123 !"£'); //=> 'foobar'
```
Type parameters
- TDelimiter
Parameters
- delimiter: TDelimiter
Returns <TArr>(arr: TArr[]) => (TDelimiter | TArr)[][]

Returns a string containing letters from text.
- - <TArr>(arr: TArr[]): (TDelimiter | TArr)[][]
 - Type parameters
 - TArr
 Parameters
 - arr: TArr[]
 Returns (TDelimiter | TArr)[][]

Const kebabCase

kebabCase(value: string): string

Returns value in kebab-case.

memberof

core

since

0.1.0

see

snakeCase

example

kebabCase(''); //=> ''
kebabCase('foo'); //=> 'foo'
kebabCase('fooBar'); //=> 'foo-Bar'
kebabCase('FOO'); //=> 'FOO'
kebabCase('foo bar'); //=> 'foo-bar'
kebabCase('fooBarBazQUX'); //=> 'foo-Bar-Baz-QUX'
kebabCase('FooBar'); //=> 'Foo-Bar'
kebabCase('--foo-bar'); //=> 'foo-bar'
kebabCase('__FOO_BAR__'); //=> 'FOO-BAR'

Parameters

value: string

string to alter.

Returns string

value in kebab-case

Const lowerCase

lowerCase(value: string): string

Returns value in 'lower case'.

memberof

core

since

0.1.0

see

upperCase

example

lowerCase(''); //=> ''
lowerCase('foo'); //=> 'foo'
lowerCase('fooBar'); //=> 'foo bar'
lowerCase('FOO'); //=> 'foo'
lowerCase('foo bar'); //=> 'foo bar'
lowerCase('fooBarBazQUX'); //=> 'foo bar baz qux'
lowerCase('FooBar'); //=> 'foo bar'
lowerCase('__foo_bar'); //=> 'foo bar'
lowerCase('__FOO_BAR__'); //=> 'foo bar'

Parameters

value: string

Value to alter.

Returns string

value in 'lower case'.

Const mapWords

mapWords(transformer: (word: string) => string, joinDelimiter?: string): (value: string) => string

Finally returns a string with all words (via toWords) in value mapped to new values via transformer, and delimited by joinDelimiter.
memberof

core

since

0.1.0

see

map toWords

example
```
const toWordLength = word => word.length.toString();
mapWords(toWordLength)(''); //=> ''
mapWords(toWordLength)('a ab abc'); //=> '1 2 3'
mapWords(toWordLength, ',')('a ab abc'); //=> '1,2,3'
```
Parameters
- transformer: (word: string) => string
  
  Returns a new word.
  - - (word: string): string
    - Parameters
      - word: string
      Returns string
- joinDelimiter: string = ' '
  
  string to delimit words (optional, defaults to ' ').
Returns (value: string) => string
- - (value: string): string
  - Parameters
    - value: string
      
      string with words to map.
    Returns string

Const pascalCase

pascalCase(value: string): string

Returns value in PascalCase.

memberof

core

since

0.1.0

see

camelCase

example

pascalCase(''); //=> ''
pascalCase('foo'); //=> 'Foo'
pascalCase('fooBar'); //=> 'FooBar'
pascalCase('FOO'); //=> 'Foo'
pascalCase('foo bar'); //=> 'FooBar'
pascalCase('fooBarBazQUX'); //=> 'FooBarBazQux'
pascalCase('FooBar'); //=> 'FooBar'
pascalCase('--foo-bar'); //=> 'FooBar'
pascalCase('__FOO_BAR__'); //=> 'FooBar'

Parameters

value: string

String to alter.

Returns string

value in PascalCase.

Const pluralize

pluralize(count?: number, options?: PluralizeOptions): (value: string) => string

Provides basic pluralization by finally returning value if it does not need pluralization (i.e., if value is an empty string, or countis0or less, orvalueis in already in plural form according tooptions.pluralMap), else returns a pluralized form of value(i.e., suffixed with eitheroptions.pluralSuffix, or a suffix provided by options.pluralMapwhich takes priority overoptions.pluralSuffix`).
memberof

core

since

0.1.0

example
```
pluralize(1)(''); //=> ''
pluralize()(''); //=> ''
[-2, -1, -0].map(c => pluralize(c)('page')) //=> ['page', 'page', 'page']
[1, 2, 3].map(c => pluralize(c)('page')) //=> ['pages', 'pages', 'pages']
pluralize(1, { pluralSuffix: 'es' })('foo'); //=> 'fooes'
['foo', 'baz'].map(pluralize(1, { pluralMap: { foo: '', baz: 'es' } })) //=> ['foo', 'bazes']
pluralize(1, { pluralSuffix: 'SUFFIX' pluralMap: { foo: 'MAP' } })('foo'); //=> 'fooMAP'
```
Parameters
- count: number = 0
  
  Integer indicating whether to pluralize (optional, defaults to 0, pluralizes if count is 1 or greater, else returns unchanged value)
- options: PluralizeOptions = {}
Returns (value: string) => string

Finally returns a string containing value in its pluralized form.
- - (value: string): string
  - Parameters
    - value: string
    Returns string

Const pluralizeWords

pluralizeWords(countMap?: Record<string, number>, joinDelimiter?: string): (value: string) => string

Finally returns a string containing all words (via toWords) in value in their pluralized form (via pluralize) & delimited by joinDelimiter (optional, defaults to ' ').
memberof

core

since

0.1.0

see

mapWords pluralize toWords

example
```
pluralizeWords({ foo: 1 })(''); //=> ''
[-2, -1, 0].map(c => pluralizeWords({ foo: c, bar: c, baz: c })('foo bar baz'); //=> 'foo bar baz'
[1, 2, 3].map(c => pluralizeWords({ foo: c, bar: c, baz: c })('foo bar baz'); //=> 'foos bars bazs'
pluralizeWords({ foo: 1 }, ',')('foo bar baz'); //=> 'foos,bar,baz'
```
Parameters
- countMap: Record<string, number> = {}
 
 Object mapping words to their count where count is an integer indicating whether to pluralize the word
- joinDelimiter: string = ' '
 
 A string to delimit words in the returned string (optional, defaults to ''). pluralizeWordsd form (takes priority over options.pluralSuffix).
Returns (value: string) => string

Finally returns a string containing value with all words in their pluralized form.
- - (value: string): string
 - Parameters
 - value: string
 Returns string

Const randomHexColor

randomHexColor(value?: string, ignoredHexColors?: IgnoredHexColors): string

Returns a valid hexadecimal color string from value where all color chunks are randomly generated (unless ignored via optional IgnoredHexColors which will have their color chunks equal to those in value).
memberof

core

since

0.1.0

see

isHexColor

example
```
 randomHexColor(); //=> #vvvvvv where v is a random hexadecimal digit
 randomHexColor('#000000'); //=> #vvvvvv where v is a random hexadecimal digit
 randomHexColor('#000000', { red: true }); //=> #00vvvv where v is a random hexadecimal digit
 randomHexColor('#111111', { red: true }); //=> #110000 where where v is a hexadecimal digit
 randomHexColor('#000000', { red: true, green: true }); //=> #0000vv where where v is a random hexadecimal digit
 randomHexColor('#000000', { red: true, green: true, blue: true }); //=> #000000 where where v is a random hexadecimal digit
```
Parameters
- value: string = ...
  
  A string containing a valid hexadecimal color string to randomize (optional, defaults to #000000 which is also the default for a value with an invalid hexadecimal color string).
- ignoredHexColors: IgnoredHexColors = {}
  
  An object indicating which color chunks of a hexadecimal color string should not be randomised (optional, defaults to {}).
Returns string

A string containing a valid hexadecimal color string where all color chunks are randomized unless ignored via IgnoredHexColors.

Const repeat

repeat(count: number): (value: string) => string

Finally returns value repeated count times.
memberof

core

since

0.1.0

example
```
repeat(4)(''); //=> ''
repeat(4)('a'); //=> 'aaaa'
repeat(4)('foo '); //=> 'foo foo foo foo '
repeat(0)('foo'); //=> ''
repeat(-1)('foo'); //=> ''
```
Parameters
- count: number
  
  Positive integer indicating the number of times value is repeated (defaults to 0 if negative).
Returns (value: string) => string

Finally returns a string containing value repeated count times.
- - (value: string): string
  - Parameters
    - value: string
    Returns string

Const replaceAll

replaceAll(find: string, replace?: string): (value: string) => string

Finally returns value with all matching occurances of find replaced with replace.
memberof

core

since

0.1.0

see

replaceFirst

example
```
replaceAll('bar', 'qux')(''); //=> ''
replaceAll('bar')('foo bar baz bar'); //=> 'foo  baz '
replaceAll('bar', 'qux')('foo bar baz bar'); //=> 'foo qux baz qux'
```
Parameters
- find: string
  
  string to replace.
- replace: string = ''
  
  string to replace find with.
Returns (value: string) => string

Finally returns value with all matching occurances of find replaced with replace.
- - (value: string): string
  - Parameters
    - value: string
      
      string to search & replace in.
    Returns string

Const replaceFirst

replaceFirst(find: string, replace?: string): (value: string) => string

Finally returns value with the first matching occurance of find replaced with replace.
memberof

core

since

0.1.0

see

replaceAll

example
```
replaceFirst('bar', 'qux')(''); //=> ''
replaceFirst('bar')('foo bar baz bar'); //=> 'foo  baz bar'
replaceFirst('bar', 'qux')('foo bar baz bar'); //=> 'foo qux baz bar'
```
Parameters
- find: string
  
  string to replace.
- replace: string = ''
  
  string to replace find with.
Returns (value: string) => string

Finally returns value with the first matching occurance of find replaced with replace.
- - (value: string): string
  - Parameters
    - value: string
      
      string to search & replace in.
    Returns string

Const sentenceCase

sentenceCase(value: string): string

Returns value in 'Sentence case'.

memberof

core

since

0.1.0

see

titleCase

example

sentenceCase(''); //=> ''
sentenceCase('foo'); //=> 'Foo'
sentenceCase('fooBar'); //=> 'Foo bar'
sentenceCase('FOO'); //=> 'Foo'
sentenceCase('foo bar'); //=> 'Foo bar'
sentenceCase('fooBarBazQUX'); //=> 'Foo bar baz qux'
sentenceCase('FooBar'); //=> 'Foo bar'
sentenceCase('__foo_bar'); //=> 'Foo bar'
sentenceCase('__FOO_BAR__'); //=> 'Foo bar'

Parameters

value: string

string to alter.

Returns string

value in 'Sentence case'.

Const snakeCase

snakeCase(value: string): string

Returns value in snake_case.

memberof

core

since

0.1.0

see

snakeCase

example

snakeCase(''); //=> ''
snakeCase('foo'); //=> 'foo'
snakeCase('fooBar'); //=> 'foo_Bar'
snakeCase('FOO'); //=> 'FOO'
snakeCase('foo bar'); //=> 'foo_bar'
snakeCase('fooBarBazQUX'); //=> 'foo_Bar_Baz_QUX'
snakeCase('FooBar'); //=> 'Foo_Bar'
snakeCase('__foo_bar'); //=> 'foo_bar'
snakeCase('__FOO_BAR__'); //=> 'FOO_BAR'

Parameters

value: string

string to alter.

Returns string

value in snake_case.

Const split

split(delimiter?: string | RegExp, limit?: number): (value: string) => string[]

Finally returns an array containing a total of limit strings from value that were previously delimited by delimiter.
memberof

core

since

0.1.0

example
```
split('')(''); //=> []
split()('foo bar baz'); //=> ['foo bar baz']
split('qux')('foo bar baz'); //=> ['foo bar baz']
split('')('foo'); //=> ['f', 'o', 'o']
split(' ', 2)('foo bar baz'); //=> ['foo', 'bar']
```
Parameters
- Optional delimiter: string | RegExp
- Optional limit: number
Returns (value: string) => string[]

Finally returns an array containing a total of limit strings from value that were previously delimited by delimiter.
- - (value: string): string[]
  - Parameters
    - value: string
    Returns string[]

Const startsWith

startsWith(target: string): (value: string) => boolean

Returns true if 'value' starts with target, else returns false.
memberof

core

since

0.1.0

example
```
startsWith('')(''); //=> true
startsWith('foo')('foo bar baz'); //=> true
startsWith('bar')('foo bar baz'); //=> false
startsWith('baz')('foo bar baz'); //=> false
startsWith('qux')('foo bar baz'); //=> false
```
Parameters
- target: string
  
  string to search for.
Returns (value: string) => boolean

true if 'value' starts with target, else returns false.
- - (value: string): boolean
  - Parameters
    - value: string
      
      string to search in.
    Returns boolean

Const stringCount

stringCount(value: string): number

Returns the number of characters in value.
memberof

core

since

0.1.0

see

count

example
```
stringCount(''); //=> 0
stringCount('abc'); //=> 3
```
Parameters
- value: string
  
  string to test.
Returns number

number of characters in value

Const stringCountIs

stringCountIs(count: number): (value: string) => boolean

Finally returns true if values's total characters equals count, else returns false.
memberof

core

since

0.1.0

see

countIs stringCount

example
```
stringCountIs(0)(''); //=> true
stringCountIs(3)('abc'); //=> true
```
Parameters
- count: number
  
  The expected count.
Returns (value: string) => boolean

Finally returns true if values's total characters equals count, else returns false.
- - (value: string): boolean
  - Parameters
    - value: string
      
      string to test.
    Returns boolean

Const stringCountIsAny

stringCountIsAny(value: string): boolean

Returns true if values's total characters is greater than 0, else returns false.
memberof

core

since

0.1.0

see

countIsAny stringCount stringCountIs

example
```
stringCountIsAny(0)(''); //=> false
stringCountIsAny(3)('abc'); //=> true
```
Parameters
- value: string
  
  string to test.
Returns boolean

true if values's total characters is greater than 0, else returns false.

Const stringCountIsNone

stringCountIsNone(value: string): boolean

Returns true if values's total characters is 0, else returns false.
memberof

core

since

0.1.0

see

countIsNone stringCount stringCountIsNone

example
```
stringCountIsNone(0)(''); //=> true
stringCountIsNone(3)('abc'); //=> false
```
Parameters
- value: string
  
  string to test.
Returns boolean

true if values's total characters is 0, else returns false.

Const stringEquals

stringEquals(value1: string): (value2: string) => boolean

Finally returns true if the literal string values of value1 & value2 are equal, else returns false.
memberof

core

since

0.1.0

see

equals

example
```
stringEquals('')(''); //=> true
stringEquals('foo bar')('foo bar'); //=> true
stringEquals('foo bar')('foo baz'); //=> false
```
Parameters
- value1: string
  
  First value to test.
Returns (value2: string) => boolean

Finally returns true if the literal string values of value1 & value2 are equal, else returns false.
- - (value2: string): boolean
  - Parameters
    - value2: string
      
      Second value to test.
    Returns boolean

Const stringExcludes

stringExcludes(...elements: any[]): (value: string) => boolean

Inverse of stringIncludes (i.e., finally returns true if value does not include all elements, else returns false).
memberof

core

since

0.1.0

see

excludes stringIncludes

example
```
stringExcludes('foo')('') //=> true
stringExcludes('foo')('foo bar baz') //=> false
stringExcludes('qux')('foo bar baz') //=> true
stringExcludes('foo', 'bar')('foo bar baz') //=> false
```
Parameters
- Rest ...elements: any[]
  
  Elements to check for.
Returns (value: string) => boolean

Finally returns true if value does not include all elements, else returns false
- - (value: string): boolean
  - Parameters
    - value: string
      
      string to test.
    Returns boolean

Const stringHead

stringHead(value: string): string

Returns the first character of value.
memberof

core

since

0.1.0

see

head

example
```
stringHead(''); //=> ''
stringHead('foo'); //=> 'F'
stringHead('foo bar'); //=> 'F'
```
Parameters
- value: string
  
  string to use.
Returns string

The first character of value

Const stringIf

stringIf(predicate: (value: string) => boolean, defaultValue?: string): (value: string) => string

Finally returns value if predicate returns true, else returns defaultValue.
memberof

core

since

0.1.0

example
```
stringIf(() => true, 'foo')('abc'); //=> 'abc'
stringIf(() => false, 'foo')('abc'); //=> 'foo'
```
Parameters
- predicate: (value: string) => boolean
  
  Returns true to indicate value should finally be returned, else returns false to indicate defaultValue should be returned.
  - - (value: string): boolean
    - Parameters
      - value: string
      Returns boolean
- defaultValue: string = ''
  
  Value to return if predicate returns false (optional, defaults to empty string).
Returns (value: string) => string

Finally returns value if predicate returns true, else returns defaultValue.
- - (value: string): string
  - Parameters
    - value: string
    Returns string

Const stringIncludes

stringIncludes(...elements: any[]): (value: string) => boolean

Finally returns true if value includes all elements, else returns false.
memberof

core

since

0.1.0

see

includes

example
```
stringIncludes('foo')('') //=> false
stringIncludes('qux')('foo bar baz') //=> false
stringIncludes('foo')('foo bar baz') //=> true
stringIncludes('foo', 'bar')('foo bar baz') //=> true
stringIncludes('foo', 'qux')('foo bar baz') //=> true
```
Parameters
- Rest ...elements: any[]
  
  Elements to check for.
Returns (value: string) => boolean

Finally returns true if value includes all elements, else returns false.
- - (value: string): boolean
  - Parameters
    - value: string
      
      string to use.
    Returns boolean

Const stringIncludesLower

stringIncludesLower(...elements: string[]): (value: string) => boolean

Similar to stringIncludes but treats elements and value as lowercase. I.e., finally returns true if value includes all elements (where value and elements are always treated as lowercase), else returns false.
memberof

core

since

0.1.0

see

lowerCase stringIncludes

example
```
stringIncludesLower('foo')('') //=> false
stringIncludesLower('qux')('foo bar baz') //=> false
stringIncludesLower('foo', 'bar')('foo bar baz') //=> true
stringIncludesLower('FOO', 'BAR')('foo bar baz') //=> true
```
Parameters
- Rest ...elements: string[]
  
  Elements to check for.
Returns (value: string) => boolean

finally returns true if value includes all elements, else returns false
- - (value: string): boolean
  - Parameters
    - value: string
      
      string to use.
    Returns boolean

Const stringOr

stringOr(defaultValue?: string): (value: any) => string

Finally returns value if it is valid via isString, else returns defaultValue.
memberof

core

since

0.1.0

see

isString valueIf

example
```
stringOr('foo')(); //=> 'foo'
stringOr('foo')(1); //=> 'foo'
stringOr('foo')('bar'); //=> 'bar'
```
Parameters
- defaultValue: string = ''
Returns (value: any) => string

Finally returns value if it is valid via isString, else returns defaultValue.
- - (value: any): string
  - Parameters
    - value: any
      
      Value to test.
    Returns string

Const stringToArray

stringToArray<TValue>(value?: string, defaultValue?: TValue[]): any

Convenience method similar to stringToObject but focuses on arrays, i.e., finally returns value as an array if value is a valid JSON string, else returns defaultValue.
memberof

core

since

1.0.0

see

stringToObject

example
```
stringToArray('') //=> []
stringToArray('foo') //=> []
stringToArray('foo', [4]) //=> [4]
stringToArray([1, 2, 3]) //=> [1, 2, 3]
```
Type parameters
- TValue
Parameters
- value: string = ''
  
  string to convert to an array (optional, defaults to '').
- defaultValue: TValue[] = []
  
  array to return if value is not a valid JSON string (optional, defaults to []).
Returns any

value as an array.

Const stringToCharCodes

stringToCharCodes(value: string): number[]

Returns value as an array of character codes.
memberof

core

since

1.0.0

see

stringToArray

example
```
stringToCharCodes() //=> Error
stringToCharCodes('') //=> []
stringToCharCodes('foo bar') //=> [102, 111, 111, 32, 98, 97, 114]
```
Parameters
- value: string
  
  string to convert to an array (optional, defaults to '').
Returns number[]

value as an array of character codes.

Const stringToHash

stringToHash(value: string): number

Returns value as a positive hash number.

Useful for converting strings to pseudo-unique IDs that attempt to be unique to the string but there is a possibility of an ID being shared by multiple strings.
memberof

core

since

1.0.0

see

stringToCharCodes

example
```
stringToCharCodes() //=> Error
stringToCharCodes('') //=> 0
stringToCharCodes('foo bar') //=> 682507847
```
Parameters
- value: string
  
  string to convert to hash.
Returns number

value as a positive hash number.

Const stringToHex

stringToHex(value: string): string

Returns value as a string hexadecimal representation of character codes.
memberof

core

since

1.0.0

see

stringToCharCodes

example
```
stringToCharCodes() //=> Error
stringToCharCodes('') //=> ''
stringToCharCodes('foo bar') //=> '666F6F20626172'
```
Parameters
- value: string
  
  string to convert to hex.
Returns string

value as a string hexadecimal representation of character codes.

Const stringToHexColor

stringToHexColor(value: string): string

Returns value as a valid hex color (i.e., a positive 6 digit hexadecimal prepended by '#' where any letters are uppercase).

Useful for converting strings to pseudo-unique IDs that attempt to be unique to the string but there is a possibility of an ID being shared by multiple strings.
memberof

core

since

1.0.0

see

stringToHex stringToHash

example
```
stringToCharCodes() //=> Error
stringToCharCodes('') //=> #000000
stringToCharCodes('foo bar') //=> #28AE3E
```
Parameters
- value: string
  
  string to convert to hex color.
Returns string

value as valid hex color.

Const stringToObject

stringToObject<TValue>(value?: string, defaultValue?: Record<string, TValue>): any

Inverse of objectToString, i.e., finally returns value as an object if value is a valid JSON string, else returns defaultValue.
memberof

core

since

0.1.0

see

objectToString

example
```
stringToObject('') //=> {}
stringToObject('foo') //=> {}
stringToObject('foo', { d: 4 }) //=> { d: 4 }
stringToObject({"a":1,"b":"2","c":3}) //=> { a: 1, b: '2', c: 3 }
```
Type parameters
- TValue
Parameters
- value: string = ''
 
 string to convert to object (optional, defaults to '').
- defaultValue: Record<string, TValue> = {}
 
 object to return if value is not a valid JSON string (optional, defaults to {}).
Returns any

value as an object.

Const stringWrap

stringWrap(wrapper: string): (value: string) => string

Finally returns value with wrapper prepended & appended.
memberof

core

since

0.1.0

example
```
stringWrap('"')('') //=> '""'
stringWrap('"')('foo bar baz') //=> "foo bar baz"
```
Parameters
- wrapper: string
  
  string to wrap value with.
Returns (value: string) => string

Finally returns value with wrapper prepended & appended.
- - (value: string): string
  - Parameters
    - value: string
      
      string to wrap.
    Returns string

Const titleCase

titleCase(value: string): string

Returns value in 'Title Case'.

memberof

core

since

0.1.0

see

pascalCase sentenceCase

example

titleCase(''); //=> ''
titleCase('foo'); //=> 'Foo'
titleCase('fooBar'); //=> 'Foo Bar'
titleCase('FOO'); //=> 'Foo'
titleCase('foo bar'); //=> 'Foo Bar'
titleCase('fooBarBazQUX'); //=> 'Foo Bar Baz Qux'
titleCase('FooBar'); //=> 'Foo Bar'
titleCase('__foo_bar'); //=> 'Foo Bar'
titleCase('__FOO_BAR__'); //=> 'Foo Bar'

Parameters

value: string

string to alter.

Returns string

value in 'Title Case'.

Const toDigitChars

toDigitChars(text: string): string

Returns a string containing digit characters (i.e., 0-9) in text.
memberof

core

since

1.0.0

example
```
toDigitChars(); //=> Error
toDigitChars(''); //=> ''
toDigitChars('foo bar 0123.456,789 !"£'); //=> '0123456789'
```
Parameters
- text: string
  
  string to return letters for.
Returns string

Returns a string containing digits from text.

Const toLetterChars

toLetterChars(text: string, keepSpacing?: boolean): string

Returns a string containing letter characters (i.e., a-z with casing preserved) in text.

Spacing (excluding leading/trailing space characters, which are always removed) can be optionally kept when keepSpacing is true, else all space characters are removed.
memberof

core

since

1.0.0

example
```
toLetterChars(); //=> Error
toLetterChars(''); //=> ''
toLetterChars(' foo bar  qux 123 !"£ '); //=> 'foobarqux'

// Keep spacing.
toLetterChars(' foo bar  qux 123 !"£ ', true); //=> 'foo bar qux'
```
Parameters
- text: string
  
  string to return letters for.
- keepSpacing: boolean = false
  
  Whether to keep spacing in returned string (optional, defaults to false).
Returns string

Returns a string containing letters from text.

Const toLetterNumbers

toLetterNumbers(text: string): string

Returns text as an array of numbers where each number is the incrementing number representation of letter characters where space character is considered the 0, 'a' is 1, etc. until 'z' which is 26.
memberof

core

since

1.0.0

example
```
toLetterChars(); //=> Error
toLetterChars(''); //=> ''
toLetterChars('foo bar 123 !"£'); //=> 'foobar'
```
Parameters
- text: string
  
  string to return letters for.
Returns string

Returns a string containing letters from text.

Const toWords

toWords(wordRegex?: RegExp): (text: string) => string[]

Finally returns an array of strings matching wordRegex.
memberof

core

since

0.1.0

example
```
toWords(''); //=> []
toWords('F Foo foo fooBarBazQUX'); //=> ['F', 'Foo', 'foo', 'foo', 'Bar', 'Baz', 'QUX'],
```
Parameters
- wordRegex: RegExp = ...
  
  Regular expression to detect words (optional, defaults to omit non-alphanumeric characters before extracting space-delimited strings, letters, numbers, and toWords within special cases like camelCase, etc.).
Returns (text: string) => string[]

Finally returns an array of strings matching wordRegex.
- - (text: string): string[]
  - Parameters
    - text: string
      
      string to alter.
    Returns string[]

Const trim

trim(value: string): string

Returns value without leading or trailing spaces.
memberof

core

since

0.1.0

example
```
trim(''); //=> ''
trim(' '); //=> ''
trim('abc'); //=> 'abc'
trim(' abc '); //=> 'abc'
```
Parameters
- value: string
  
  string to trim.
Returns string

value` without leading or trailing spaces.

Const truncate

truncate(options?: TruncateOptions): (value: string) => string

Finally returns value truncated based on optional TruncateOptions.

memberof

core

since

0.1.0

see

slice

example

truncate({ length: 4 })(''); //=> '...'
const text = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vivamus vestibulum convallis viverra fusce.';
truncate()(text); //=> 'Lorem ipsum dolor sit amet,...'
truncate({ length: 10 })(text); //=> 'Lorem i...'
truncate({ from: 'dolor' })(text); //=> 'Lorem ipsum ...'
truncate({ trailing: '[omitted]' })(); //=> 'Lorem ipsum dolor sit[omitted]'

Parameters

options: TruncateOptions = {}

Returns (value: string) => string

Finally returns value truncated based on optional TruncateOptions.

- (value: string): string
- Parameters
  - value: string
  Returns string

Const upperCase

upperCase(value: string): string

Returns value in 'UPPER CASE'.

memberof

core

since

0.1.0

see

lowerCase

example

upperCase(''); //=> ''
upperCase('foo'); //=> 'FOO'
upperCase('fooBar'); //=> 'FOO BAR'
upperCase('FOO'); //=> 'FOO'
upperCase('foo bar'); //=> 'FOO BAR'
upperCase('fooBarBazQUX'); //=> 'FOO BAR BAZ QUX'
upperCase('FooBar'); //=> 'FOO BAR'
upperCase('__foo_bar'); //=> 'FOO BAR'
upperCase('__FOO_BAR__'); //=> 'FOO BAR'

Parameters

value: string

Value to alter.

Returns string

value in 'UPPER CASE'.

Index

Array Functions

Boolean Functions

Function Functions

Logic Functions

Number Functions

Object Functions

Other Functions

Promise Functions

String Functions

Array Functions

Const all

Type parameters

T

Parameters

predicate: (value: T, index: number) => boolean

Parameters

value: T

index: number

Returns boolean

Returns (array: T[]) => boolean

Parameters

array: T[]

Returns boolean

Const allFalse

Parameters

array: any[]

Returns boolean

Const allNotNil

Parameters

array: any[]

Returns boolean

Const allTrue

Parameters

array: any[]

Returns boolean

Const any

Type parameters

T

Parameters

predicate: (value: T, index: number) => boolean

Parameters

value: T

index: number

Returns boolean

Returns (array: T[]) => boolean

Parameters

array: T[]

Returns boolean

Const anyFalse

Parameters

array: any[]

Returns boolean

Const anyNil

Parameters

array: any[]

Returns boolean

Const anyTrue

Parameters

array: any[]

Returns boolean

Const arrayIf

Type parameters

T

Parameters

predicate: (array: T[]) => boolean

Parameters

array: T[]

Returns boolean

defaultArray: T[] = []

Returns (array: T[]) => T[]

Parameters

array: T[]

Returns T[]

Const arrayOr

Type parameters

T

Parameters

defaultArray: T[] = []

Returns (array: any) => T[]