skald

1.22.2 • Public • Published

skald

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Shakeable, tested javascript utility functions in a pure functional programming style

What is it?

Short answer: Yet another utility library

Long answer: Skald is a utility library to aid in pure functional javascript programming. It's meant to be shakeable, light-weight, and 100% tested. The entire library will compile down to < 7kb before gzipping (at present) and contains ~90 functions.

How do you use it?

Here's an example of a block of a short ES6 module

const sumPlusOne = arr => arr
    .map(val => val + 1)
    .reduce((acc, val) => acc + val, 0);
 
export default sumPlusOne;

Here's an example of how that code might be written with skald

import { add, compose, mapBy, reduceBy } from 'skald';
 
const addOne = add(1);
const mapByAddOne = mapBy(addOne);
const reduceByAdd = reduceBy(add, 0);
const sumPlusOne = compose(reduceByAdd, mapByAddOne);
 
export default sumPlusOne;

It's a little more code in your module, but:

  • We didn't need to declare any functions directly
  • We were able to reuse a simple function like add
  • The code is easy to understand
  • It slims down nicely when run through a build minification

That's about it.

Functions

add(a, b)number

Add two numbers

and(...args)boolean

Determine if all arguments are truthy or if array is truthy

andWith(fns, val)boolean | function

Take an array of functions (or values) and determine if all results are true given value

appendTo(str, append)function | string

Append string to the end of another string

apply(fns, vals)function | array

Apply functions from an array to corresponding index in other array

args(...vals)Array

Returns an array of passed arguments

at(index, val)*

Returns copy of entry or character at given index in string or array

attempt(toTry, onError)*

Attempt something. If an error is thrown, return something else. (Wrapper for try / catch)

bindTo(fn, ...args)function

Takes a function and arguments. Leaves undefined arguments unbound and binds defined arguments to their position in arguments list.

call(fn, arr)function

Execute function with array as arguments

callback(cb, predicate)*

Take two arguments and if second argument is truthy, return first.

callbackWith(cb, predicate, val)*

Take two arguments and if second argument is truthy, return first based on val

concat(val)function

Returns a function which accepts no params and returns the passed value

compose(...args)function

Compose functions from right to left

composeL(...args)function

Compose functions from right to left

concat(...args)function | Array

Returns a new array, which is a merge of at least two arrays

curry(fn, ...args)function | *

Curry arguments to function and return new function

deepEquals(a, b)boolean | function

Allow comparison of two objects or arrays

defaultTo(def, val)*

Sets default value if passed value is falsy

define(fn)function | *

Take a function with a known signature and allow arguments to be passed until it executes

divide(a, b)number | function

Divide two numbers

equals(a, b)boolean | function

Determine if two values are equal

everyBy(fn, arr)function | boolean

Determine if all values in array satisfy function

excludes(search, val)boolean | function

Returns true if string is not in string or array

executeWith(val, fn)function | *

Create a function which executes a function based on a defined value

executeWith(fn, ...args)function

Create a function which executes a function with each arg being transformed by a function

fillBy(val, arr)function | arr

Fill an array with a defined value

filterBy(fn, arr)function | Array

Filter elements in an array by function

getEmptyArr()Array

Returns an empty array

getEmptyObj()Object

Returns an empty object

getObject(prop, value)function | Object

Get an object with single property and value

getProp(prop, obj)function | *

Get property of an object

gt(a, b)function | boolean

Determine if first value is greater than

gte(a, b)function | boolean

Determine if value is greater than or equal to other value

has(obj, key)function | boolean

Return true if object has key

identity()*

A function which returns whatever is passed into it

includes(search, val)boolean | function

Returns true if string is in string or array

invoke(fn)*

Invoke a function without arguments

isArray(val)boolean

Determine if value is array

isBoolean(val)boolean

Determine if value is boolean;

isEmpty(val)boolean

Check whether object, array, or string is empty

isFunction(val)boolean

Determine if value is function

isNaN(val)boolean

Determine if value is NaN

isNull(val)boolean

Determine if value is null

isNumber(val)boolean

Determine if value is function

isObject(val)boolean

Detemine if value is object

isPromise(val)boolean

Take a value and determine if it is a promise

isPropertyOf(key, obj)boolean

Determine if string is property of object

isString(val)boolean

Determine if value is string

isUndefined(val)boolean

Determine if value is undefined

iterate(fn, len)Array

Return array of function iterations of specified length generated from 0-based index

joinBy(delimiter, arr)function | string

Join array to string, delimited by other string

lt(a, b)function | boolean

Determine if value is less than other value

lte(a, b)function | boolean

Determine if value is less than or equal to other value

mapBy(fn, arr)function | Array

Map elements in an array by function

maybe(fn, val)function | *

Execute a function if the argument is not null or undefined

memoize(fn, [function])function

Cache return contents of functions

merge(...args)Object

Returns new object, which is a shallow merge of multiple objects

multiply(a, b)function | number

Multiply two numbers together

none(...args)boolean

Returns true if no argument or array value is true

noop()undefined

Executes a noop

not(val)boolean | function

Returns false if truthy, true if falsy, negation if function

notEquals(a, b)function | boolean

Return true if two values are not equal

or(...args)boolean

Determine if at least one argument or array value is truthy

orWith(args, val)boolean | function

Take an array of functions (or values) and determine if one result is true given value

orderBy(template, src)function | Array

Generate array based on template of indexes and source

power(exponent, base)function | number

Return exponent from one number to another

prependTo(str, append)function | string

Prepend string to the beginning of another string

reduceBy(fn, accumulator, arr)function | *

Reduce array to new value by function

replaceWith(search, rep, str)string | function

Replace search with new value in string

reverse(fn)function

Take a function and return a function which accepts args in reverse order

setProp(prop, value, obj)function | Object

Returns a copy of an object with a new name / value pair

sliceFrom(start, end, val)function | Array | string

Slice an array or string

someBy(fn, arr)function | boolean

Determine if at least one value in array satisfy function

splitBy(search, str)function | Array

Split string to array by another string

spread(...args)Array

Convert argument list to array (alias args)

subtract(a, b)function | number

Subtract one number from another

ternary(failure, success, predicate)*

Return success or failure based on predicate evaluation. If success or failure are functions, returns executed result.

ternaryL(predicate, success, failure)*

Return success or failure based on predicate evaluation. If success or failure are functions, returns executed result.

ternaryWith(failure, success, predicate, val)*

Return success or failure based on predicate evaluation. If success or failure are functions, returns executed result with passed in parameter;

toArray(...args)Array

Force args to array if not arrays

toBoolean(value)boolean

Returns boolean value and converts string 'false' to false

toFunction(value)function

Returns function which returns value if value is not a function.

toNumber(value)number

Parses int or float or Infinity to numeric value

toObject(value)Object

Forces value into object. If not object, returns {}

toPromise(val)Promise

Take a value and if not a promise, make it a promise

toString(value)string

Converts value to string. Converts undefined to empty string.

traverse(obj, path)*

Safely traverse object nested properties

traverseR(path, obj)*

Safely traverse object nested properties

typeOf(val)string

Returns typeof value

add(a, b) ⇒ number

Add two numbers

Kind: global function
Since: 1.0.0

Param Type
a number
b number

Example

add(1,2); //=> 3
    add(2)(3); //=> 5

and(...args) ⇒ boolean

Determine if all arguments are truthy or if array is truthy

Kind: global function
Since: 1.0.0

Param Type
...args *

Example

and(true, true); //=> true
    and([true, true]); //=> true
    and(true, true, false); //=> false

andWith(fns, val) ⇒ boolean | function

Take an array of functions (or values) and determine if all results are true given value

Kind: global function
Since: 1.10.0

Param Type
fns Array
val *

Example

const foo = val => val < 10;
    const bar = val => val > 5;
    andWith([foo, bar], 6); //=> true
    andWith([foo, bar])(1); //=> false

appendTo(str, append) ⇒ function | string

Append string to the end of another string

Kind: global function
Since: 1.13.0

Param Type
str string
append string

Example

appendTo('foo', 'bar'); //=> 'foobar'
    appendTo('bar')('baz'); //=> 'barbaz'

apply(fns, vals) ⇒ function | array

Apply functions from an array to corresponding index in other array

Kind: global function
Since: 1.11.0

Param Type
fns Array
vals Array

Example

const add1 = a => a + 1;
    const add2 = a => a + 2;
    apply([add1, add2], [0, 0]); //=> [1, 2];
    apply([add1])([1, 2, 3]); //=> [2, 2, 3];

args(...vals) ⇒ Array

Returns an array of passed arguments

Kind: global function
Since: 1.16.0

Param Type
...vals *

Example

args(1, 2, [3, 4]); //=> [1, 2, [3, 4]]

at(index, val) ⇒ *

Returns copy of entry or character at given index in string or array

Kind: global function
Since: 1.5.0

Param Type
index number
val Array | string

Example

at(2, 'foo'); //=> 'o'
    at(1)([0, 1, 2]); //=> 1

attempt(toTry, onError) ⇒ *

Attempt something. If an error is thrown, return something else. (Wrapper for try / catch)

Kind: global function
Since: 1.7.0

Param Type
toTry *
onError *

Example

attempt(() => JSON.parse('<>'), false); //=> false
    attempt(5, () => ({})); //=> 5

bindTo(fn, ...args) ⇒ function

Takes a function and arguments. Leaves undefined arguments unbound and binds defined arguments to their position in arguments list.

Kind: global function
Since: 1.8.0

Param Type
fn function
...args *

Example

const foo = (a, b, c) = a + b + c;
    bindTo(foo, 1, 2)(3); //=> 6
    bindTo(foo, undefined, 1, 2)(1); //=> 4
    bindTo(foo, undefined, undefined, 3)(1, 2); //=> 6
    bindTo(foo, undefined, 1)(1)(1); //=> 3

call(fn, arr) ⇒ function

Execute function with array as arguments

Kind: global function
Since: 1.17.0

Param Type
fn function
arr Array

Example

const foo = (a, b) => a + b;
    call(foo, [1, 2]) //=> 3
    call(foo)([2, 3]) //=> 5

callback(cb, predicate) ⇒ *

Take two arguments and if second argument is truthy, return first.

Kind: global function
Since: 1.0.0

Param Type
cb *
predicate *

Example

callback('foo', true); //=> 'foo'
    callback('foo', false); //=> null

callbackWith(cb, predicate, val) ⇒ *

Take two arguments and if second argument is truthy, return first based on val

Kind: global function
Since: 1.9.0

Param Type
cb *
predicate *
val *

Example

callbackWith(a => a, true, 3); //=> 3
    callbackWith(a => a, false, 3); //=> null

concat(val) ⇒ function

Returns a function which accepts no params and returns the passed value

Kind: global function
Since: 1.16.0

Param Type
val *

Example

cast(6); //=> () = 6;

compose(...args) ⇒ function

Compose functions from right to left

Kind: global function
Since: 1.0.0

Param Type
...args function

Example

compose(val => val + 1, val => val + 2); //=> val => val + 3

composeL(...args) ⇒ function

Compose functions from right to left

Kind: global function
Since: 1.0.0

Param Type
...args function

Example

compose(val => val + 1, val => val + 2); //=> val => val + 3

concat(...args) ⇒ function | Array

Returns a new array, which is a merge of at least two arrays

Kind: global function
Since: 1.16.0

Param Type
...args Array

Example

const([1, 2], [3, 4]); //=> [1, 2, 3, 4]

curry(fn, ...args) ⇒ function | *

Curry arguments to function and return new function

Kind: global function
Since: 1.0.0

Param Type
fn function
...args *

Example

const foo = (a, b, c) => a + b + c;
    curry(foo, 1, 2)(3); //=> 6
    curry(foo, 1)(3, 4); //=> 8
    curry(foo, 2)(3)(4); //=> 9
    curry(foo)(1)(1)(1); // => 3

deepEquals(a, b) ⇒ boolean | function

Allow comparison of two objects or arrays

Kind: global function
Since: 1.4.0

Param Type
a *
b *

Example

deepEquals({}, {}); //=> true
    deepEquals([])([]); //=> true

defaultTo(def, val) ⇒ *

Sets default value if passed value is falsy

Kind: global function
Since: 1.2.0

Param Type
def *
val *

Example

defaultTo(5, undefined); //=> 5
    defaultTo(3)(4); //=> 4

define(fn) ⇒ function | *

Take a function with a known signature and allow arguments to be passed until it executes

Kind: global function
Update:
Since: 1.0.0

Param Type
fn function

Example

const foo = (a, b, c) => a + b + c;
    const bar = define(foo);
    bar(1); // (b, c) => 1 + b + c
    bar(1)(2); // c => 1 + 2 + c
    bar(1)(2)(3); // 6

divide(a, b) ⇒ number | function

Divide two numbers

Kind: global function
Since: 1.0.0

Param Type
a number
b number

Example

divide(9, 3); //=> 3
    divide(4)(2); //=> 2

equals(a, b) ⇒ boolean | function

Determine if two values are equal

Kind: global function
Since: 1.0.0

Param Type
a *
b *

Example

equals(1, 1); //=> true
    equals(1)(2); //=> false

everyBy(fn, arr) ⇒ function | boolean

Determine if all values in array satisfy function

Kind: global function
Since: 1.17.0

Param Type
fn function
arr Array

Example

const isTrue = val => val === true;
    everyBy(isTrue, [true, true]) //=> true
    everyBy(isTrue)([true, false]) //=> false

excludes(search, val) ⇒ boolean | function

Returns true if string is not in string or array

Kind: global function
Since: 1.4.0

Param Type
search string | number
val string | Array

Example

excludes('h', 'hello'); //=> false
    excludes('a')('apple'); //=> false

executeWith(val, fn) ⇒ function | *

Create a function which executes a function based on a defined value

Kind: global function
Since: 1.11.0

Param Type
val *
fn function

Example

const addOne = a => a + 1;
    executeOn(1, addOne); //=> 2
    executeOn(2)(addOne); //=> 3

executeWith(fn, ...args) ⇒ function

Create a function which executes a function with each arg being transformed by a function

Kind: global function
Since: 1.11.0

Param Type
fn function
...args *

Example

const foo = (a, b) => a + b;
    const add1 = a => a + 1;
    const add2 = b => b + 2;
    executeWith(foo, add1, add2)(0, 0); //=> 3
    executeWith(foo, add1)(0, 0); //=> 1

fillBy(val, arr) ⇒ function | arr

Fill an array with a defined value

Kind: global function
Since: 1.17.0

Param Type
val val
arr Array

Example

fillBy(1, [undefined, undefined]); //=> [1, 1]
    fillBy(2)([undefined, undefined); //=> [2, 2]

filterBy(fn, arr) ⇒ function | Array

Filter elements in an array by function

Kind: global function
Since: 1.9.0

Param Type
fn function
arr Array

Example

const foo = val => val < 3;
    filterBy(foo, [1, 2, 4]); //=> [1, 2]
    filterBy(foo)([2,3]); //=> [2]

getEmptyArr() ⇒ Array

Returns an empty array

Kind: global function
Since: 1.16.0
Example

getEmptyArray(); //=> []

getEmptyObj() ⇒ Object

Returns an empty object

Kind: global function
Since: 1.16.0
Example

getEmptyObj(); //=> {}

getObject(prop, value) ⇒ function | Object

Get an object with single property and value

Kind: global function
Since: 1.15.0

Param Type
prop string | number
value *

Example

getObject('a', 1); //=> { a: 1 }
    getProp('b')(2); //=> { b: 2 }

getProp(prop, obj) ⇒ function | *

Get property of an object

Kind: global function
Since: 1.15.0

Param Type
prop string | number
obj Object

Example

getProp('a', { a: 1 }); //=> 1
    getProp('b')({ b: 2 }); //=> 2

gt(a, b) ⇒ function | boolean

Determine if first value is greater than

Kind: global function
Since: 1.0.0

Param Type
a number | string
b number | string

Example

gt(2, 1); //=> true
    gt('b')('c'); //=> false

gte(a, b) ⇒ function | boolean

Determine if value is greater than or equal to other value

Kind: global function
Since: 1.0.0

Param Type
a number | string
b number | string

Example

gte(1, 1); //=> true
    gte('b')('a'); //=> true

has(obj, key) ⇒ function | boolean

Return true if object has key

Kind: global function
Since: 1.9.0

Param Type
obj Object
key string

Example

has({ a: 1 }, 'a'); //=> true
   has({ a: 1 })('a'); //=> true
   has({ a: 1 })('b'); //=> false

identity() ⇒ *

A function which returns whatever is passed into it

Kind: global function
Params: * val
Since: 1.5.0
Example

identity(5); //=> 5
    identity({}); //=> {}

includes(search, val) ⇒ boolean | function

Returns true if string is in string or array

Kind: global function
Since: 1.4.0

Param Type
search string | number
val string | Array

Example

includes('h', 'hello'); //=> true
    includes('a')('apple'); //=> true

invoke(fn) ⇒ *

Invoke a function without arguments

Kind: global function
Since: 1.18.0

Param Type
fn function

Example

var foo = () => 1;
    invoke(foo); //=> 1;

isArray(val) ⇒ boolean

Determine if value is array

Kind: global function
Since: 1.0.0

Param Type
val *

Example

isArray([]); //=> true
    isArray(1); //=> false

isBoolean(val) ⇒ boolean

Determine if value is boolean;

Kind: global function
Since: 1.0.0

Param Type
val *

Example

isBoolean(1); //=> false
    isBoolean(false); //=> true

isEmpty(val) ⇒ boolean

Check whether object, array, or string is empty

Kind: global function
Since: 1.5.0

Param Type
val Object | Array | string

Example

isEmpty([]); //=> true
    isEmpty({}); //=> true
    isEmpty(''); //=> true

isFunction(val) ⇒ boolean

Determine if value is function

Kind: global function
Since: 1.0.0

Param Type
val *

Example

isFunction(1); //=> false
    isFunction(() => ({})); //=> true

isNaN(val) ⇒ boolean

Determine if value is NaN

Kind: global function
Since: 1.0.0

Param Type
val number

Example

isNaN(NaN); //=> true
    isNaN(1); //=> false

isNull(val) ⇒ boolean

Determine if value is null

Kind: global function
Since: 1.0.0

Param Type
val *

Example

isNull(null); //=> true
    isNull({}); //=> false

isNumber(val) ⇒ boolean

Determine if value is function

Kind: global function
Since: 1.0.0

Param Type
val *

Example

isNumber(1); //=> true
    isNumber([]); //=> false

isObject(val) ⇒ boolean

Detemine if value is object

Kind: global function
Since: 1.0.0

Param Type
val *

Example

isObject({}); //=> true
    isObject(1); //=> false

isPromise(val) ⇒ boolean

Take a value and determine if it is a promise

Kind: global function
Since: 1.1.0

Param Type
val *

Example

isPromise(Promise.resolve()); //=> true
    isPromise('foo'); //=> false

isPropertyOf(key, obj) ⇒ boolean

Determine if string is property of object

Kind: global function
Since: 1.13.0

Param Type
key string
obj Object

Example

isPropertyOf('foo', { foo: 'a' }); //=> true
    isPropertyOf('foo')({ bar: 'b' }); //=> false

isString(val) ⇒ boolean

Determine if value is string

Kind: global function
Since: 1.0.0

Param Type
val *

Example

isString('foo'); //=> true;
    isString(true); //=> false;

isUndefined(val) ⇒ boolean

Determine if value is undefined

Kind: global function
Since: 1.0.0

Param Type
val *

Example

isUndefined(undefined); //=> true
    isUndefined(true); //=> false

iterate(fn, len) ⇒ Array

Return array of function iterations of specified length generated from 0-based index

Kind: global function
Since: 1.9.0

Param Type
fn function
len number

Example

const foo = index => index + 1;
    iterate(foo, 3); //=> [1, 2, 3]
    iterate(foo)(2); //=> [1, 2]

joinBy(delimiter, arr) ⇒ function | string

Join array to string, delimited by other string

Kind: global function
Since: 1.13.0

Param Type
delimiter string
arr Array

Example

joinBy('.', ['foo', 'bar', 'baz']); //=> 'foo.bar.baz'
    joinBy(',')([1, 2, 3]); //=> '1.2.3';

lt(a, b) ⇒ function | boolean

Determine if value is less than other value

Kind: global function
Since: 1.0.0

Param Type
a number | string
b number | string

Example

lt(1, 2); //=> true
    lt('a')('b'); //=> true

lte(a, b) ⇒ function | boolean

Determine if value is less than or equal to other value

Kind: global function
Since: 1.0.0

Param Type
a number | string
b number | string

Example

lte(1, 1); //=> true
    lte('a')('b'); //=> true

mapBy(fn, arr) ⇒ function | Array

Map elements in an array by function

Kind: global function
Since: 1.9.0

Param Type
fn function
arr Array

Example

const foo = val => val + 1;
    mapBy(foo, [1, 2]); //=> [2, 3]
    mapBy(foo)([4, 5]); //=> [5, 6]

maybe(fn, val) ⇒ function | *

Execute a function if the argument is not null or undefined

Kind: global function
Since: 1.23.0
Author: oculus42

Param Type
fn function
val *

Example

const foo = val => val + 1;
    maybe(foo, 1); //=> 2
    maybe(foo)(null); //=> null

memoize(fn, [function]) ⇒ function

Cache return contents of functions

Kind: global function
Since: 1.9.0

Param Type Description
fn function Function to templatize
[function] template - Function to determine cache key

merge(...args) ⇒ Object

Returns new object, which is a shallow merge of multiple objects

Kind: global function
Since: 1.16.0

Param Type
...args Object

Example

merge({ a: 1 }, { b: 2}); //=> { a: 1, b: 2 }

multiply(a, b) ⇒ function | number

Multiply two numbers together

Kind: global function
Since: 1.0.0

Param Type
a number
b number

Example

multiply(2, 3); //=> 6
    multiply(2)(2); //=> 4

none(...args) ⇒ boolean

Returns true if no argument or array value is true

Kind: global function
Since: 1.4.0

Param Type
...args *

noop() ⇒ undefined

Executes a noop

Kind: global function
Since: 1.5.0

not(val) ⇒ boolean | function

Returns false if truthy, true if falsy, negation if function

Kind: global function
Since: 1.1.0

Param Type
val *

Example

const identity = a => a;
    not(1); //=> false
    not(false); //=> true
    not(identity)(true); //=> false

notEquals(a, b) ⇒ function | boolean

Return true if two values are not equal

Kind: global function
Since: 1.1.0

Param Type
a *
b *

Example

notEquals(1, 2); //=> true
    notEquals(3)(4); //=> true

or(...args) ⇒ boolean

Determine if at least one argument or array value is truthy

Kind: global function
Since: 1.0.0

Param Type
...args *

Example

or(true, false, false); //=> true
    or([false, false, true]); //=> true

orWith(args, val) ⇒ boolean | function

Take an array of functions (or values) and determine if one result is true given value

Kind: global function
Since: 1.10.0

Param Type
args Array
val *

Example

const foo = val => val > 10;
    const bar = val => val < 5;
    orWith([foo, bar], 6); //=> false
    orWith([foo, bar])(1); //=> true

orderBy(template, src) ⇒ function | Array

Generate array based on template of indexes and source

Kind: global function
Since: 1.19.0

Param Type
template Array
src Array

Example

orderBy([1, 2, 0], ['a', 'b', 'c']); //=> ['b', 'c', 'a'];
    orderBy([2, 0, 1])(['d', 'e', 'f']); //=> ['f', 'd', 'e'];

power(exponent, base) ⇒ function | number

Return exponent from one number to another

Kind: global function
Since: 1.20.0

Param Type
exponent number
base number

Example

power(2, 3); //=> 9
    power(2)(2); //=> 4

prependTo(str, append) ⇒ function | string

Prepend string to the beginning of another string

Kind: global function
Since: 1.13.0

Param Type
str string
append string

Example

prependTo('foo', 'bar'); //=> 'barfoo'
    prependTo('bar')('baz'); //=> 'bazbar'

reduceBy(fn, accumulator, arr) ⇒ function | *

Reduce array to new value by function

Kind: global function
Since: 1.9.0

Param Type
fn function
accumulator *
arr Array

Example

const foo = (acc, val) = acc + val;
    reduceBy(foo, 1, [1, 1]); //=> 3
    reduceBy(foo, 2)([2, 2]); //=> 6
    reduceBy(foo)(3)([3, 3]); //=> 9

replaceWith(search, rep, str) ⇒ string | function

Replace search with new value in string

Kind: global function
Since: 1.6.0

Param Type
search string | RegExp
rep string
str string

Example

replaceWith('f', 'b', 'foo'); //=> 'boo'
    replaceWith(/o/g)('a')('foo'); //=> 'faa'

reverse(fn) ⇒ function

Take a function and return a function which accepts args in reverse order

Kind: global function
Since: 1.1.0

Param Type
fn function

Example

const foo = (a, b, c) => a + b - c;
    reverse(foo); //=> (c)(b)(a) => c + b - a;

setProp(prop, value, obj) ⇒ function | Object

Returns a copy of an object with a new name / value pair

Kind: global function
Since: 1.21.0

Param Type
prop string | number
value *
obj Object

Example

setProp('a', 1, {}); //=> { a: 1 }
    getProp('b')(2)({}); //=> { b: 2 }

sliceFrom(start, end, val) ⇒ function | Array | string

Slice an array or string

Kind: global function
Since: 1.17.1

Param Type
start number
end number
val Array | string

Example

sliceFrom(0, 1, [1, 2, 3]) //=> [0];

someBy(fn, arr) ⇒ function | boolean

Determine if at least one value in array satisfy function

Kind: global function
Since: 1.17.0

Param Type
fn function
arr Array

Example

const isTrue = val => val === true;
    someBy(isTrue, [true, false]) //=> true
    someBy(isTrue)([false, false]) //=> false

splitBy(search, str) ⇒ function | Array

Split string to array by another string

Kind: global function
Since: 1.13.0

Param Type
search string
str string

Example

splitBy('.', 'foo.bar.baz'); //=> ['foo', 'bar', 'baz']
    splitBy(',')('1,2,3'); //=> ['1', '2', '3'];

spread(...args) ⇒ Array

Convert argument list to array (alias args)

Kind: global function
Since: 1.17.0

Param Type
...args *

Example

spread(1, 2, 3); //=> [1, 2, 3]

subtract(a, b) ⇒ function | number

Subtract one number from another

Kind: global function
Since: 1.0.0

Param Type
a number
b number

Example

subtract(3, 2); //=> 1
    subtract(2)(1); //=> 1

ternary(failure, success, predicate) ⇒ *

Return success or failure based on predicate evaluation. If success or failure are functions, returns executed result.

Kind: global function
Since: 1.0.0

Param Type
failure *
success *
predicate *

Example

ternary(1, 2, true); //=> 2
    ternary(1, 2, false); //=> 1

ternaryL(predicate, success, failure) ⇒ *

Return success or failure based on predicate evaluation. If success or failure are functions, returns executed result.

Kind: global function
Since: 1.1.0

Param Type
predicate *
success *
failure *

Example

ternaryL(true, 1, 2); //=> 1
    ternaryL(false, 1, 2); //=> 2

ternaryWith(failure, success, predicate, val) ⇒ *

Return success or failure based on predicate evaluation. If success or failure are functions, returns executed result with passed in parameter;

Kind: global function
Since: 1.9.0

Param Type
failure *
success *
predicate *
val *

Example

const foo = val => val + 1;
    const bar = val => val - 1;
    ternaryWith(bar, foo, true, 3); //=> 4
    ternaryWith(bar, foo, false, 2); //=> 1

toArray(...args) ⇒ Array

Force args to array if not arrays

Kind: global function
Since: 1.0.0

Param Type
...args *

Example

toArray([1, 2]); //=> [1, 2]
    toArray(2, 3); //=> [2, 3]

toBoolean(value) ⇒ boolean

Returns boolean value and converts string 'false' to false

Kind: global function
Since: 1.0.0

Param Type
value *

Example

toBoolean('false'); //=> false
    toBoolean({}); //=> true

toFunction(value) ⇒ function

Returns function which returns value if value is not a function.

Kind: global function
Since: 1.0.0

Param Type
value *

Example

toFunction(3); //=> () => 3
    toFunction(() => 1); //=> () => 1

toNumber(value) ⇒ number

Parses int or float or Infinity to numeric value

Kind: global function
Since: 1.0.0

Param Type
value *

Example

toNumber('Infinity'); //=> Infinity
    toNumber('1.0'); //=> 1
    toNumber({}); //=> NaN

toObject(value) ⇒ Object

Forces value into object. If not object, returns {}

Kind: global function
Since: 1.0.0

Param Type
value *

Example

toObject({ a: 1 }); //=> { a: 1 }
    toObject(null); //=> null
    toObject('foo'); //=> {}

toPromise(val) ⇒ Promise

Take a value and if not a promise, make it a promise

Kind: global function
Since: 1.1.0

Param Type
val *

Example

const foo = toPromise(5);
    foo.then(console.log); //=> 5;

toString(value) ⇒ string

Converts value to string. Converts undefined to empty string.

Kind: global function
Since: 1.0.0

Param Type
value *

Example

toString('foo'); //=> 'foo'
    toString(false); //=> 'false'
    toString(undefined); //=> ''

traverse(obj, path) ⇒ *

Safely traverse object nested properties

Kind: global function
Since: 1.6.0

Param Type
obj Object
path Array.<string>

Example

traverse({}, ['a', 'b', 'c']); //=> undefined
    traverse({ a: 1 })(['a']); //=> 1

traverseR(path, obj) ⇒ *

Safely traverse object nested properties

Kind: global function
Since: 1.14.0

Param Type
path Array.<string>
obj Object

Example

traverse(['a', 'b', 'c'], {}); //=> undefined
    traverse(['a'])({ a: 1 }); //=> 1

typeOf(val) ⇒ string

Returns typeof value

Kind: global function
Since: 1.0.0

Param Type
val *

Example

typeOf([]); //=> 'object'
    typeOf(undefined); //=> 'undefined'
    typeOf(5); //=> 'number'

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