Muse

Getting started

import {
  map,
  filter,
  ...
} from 'musejs';

Utils

map

Higher order map

map([1, 2, 3, 4], i => i + 1)
// => [2, 3, 4, 5]

filter

Higher order filter

filter([1, 'hey', '3', 4], !isNaN);
// => [1, 3, 4]

reduce

Higher order reduce

reduce([1, 2, 3, 4], (i, j) => i + j);
// => 10

foreach

Higher order forEach

forEach([1, 2, 3, 4], i => console.log (i))
// => 1
// => 2
// => 3
// => 4

reverse

Higher order reverse

reverse([1, 2, 3])
// => [3, 2, 1]

id

Return true if the value is not 0, undefined or null

filter([1, null, 4, undefined, 'Hello'], id)
// => [1, 4, 'Hello']

complement

Negates a function

let isNumber = complement(isNaN);
isNumber(1)
// => true

range

Yields a range from min to max by step

[...range(0, 10)]
// => [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

times

Performs an action n times

times(3, () => console.log ('Hello'))
// => Hello
// => Hello
// => Hello

flatten

Flatten an array

flatten([1, 2, 3, [4, [5, [6, [7, [8, 9]]]]]])
// => [1, 2, 3, 4, 5, 6, 7, 8, 9]

partial

Take a function fn and an array of args with empty spaces and returns a partial function g that take a single arg

let rgb = (r, g, b) => [r, g, b];
let varyGreen = partial(rgb, 4, null, 5);

varyGreen(4)
// => rgb(4, 4, 5);

thread

Pass a value to a list of function, one function at a time

thread(
  1,
  i => i + 1,
  i => i - 2
)
// => -1

compose

Return a function that takes a value to be threaded in a list of functions

add3AndMultiply3 = compose(add3, multiply3);
add3AndMultiply3(3);
// => 18

promisify

Transform a callback style function into a Promise style function

let readfile = promisify(fs.readFile)

let text = readfile('./test.txt')
text.then(console.log.bind(console))

isNumber, isArray, isString, isObject

Primitives type checking functions

isNumber('3')
// => true

isString('Hello')
// => true

isArray({name: guillaume})
// => false

Math

dotProduct

Dot product between 2 vectors

dotProduct([1, 2, 3], [4, 5, 6]);
// => 32

addMatrix

Matrix/vector addition

addMatrix(
  [[1, 1, 1, 1],
   [1, 1, 1, 1]],

  [[1, 1, 1, 1],
   [1, 1, 1, 1]]
)
// => [[2, 2, 2, 2], [2, 2, 2, 2]]

getRow

Returns a matrix row as a vector

getRow(
  [[1, 1, 1, 1, 1],
   [2, 2, 2, 2, 2],
   [1, 1, 1, 1, 1],
   [1, 1, 1, 1, 1]],
  1
)
// => [2, 2, 2, 2, 2]

getColumn

Returns a matrix column as a vector

getColumn(
  [[2, 1, 1, 1, 1],
   [2, 1, 1, 1, 1],
   [2, 1, 1, 1, 1],
   [2, 1, 1, 1, 1]],
   0
)
// => [2, 2, 2, 2, 2]

multMatrix

Performs a matricex multiplication

const m1 = [
  [1, 2, 3],
  [4, 5, 6]
];
const m2 = [
  [7, 8],
  [9 , 10],
  [11, 12]
]
multMatrix(m1, m2)
// => [ [58, 64],
//      [139, 154]]

matrixDimensions

Returns a matrix dimensions [rows, columns]

const [rows, columns] = matrixDimensions(myMatrix);

transpose

Transpose a matrix

console.log (transpose([
  [1, 2, 3],
  [4, 5, 6],
  [7, 8, 9]
]))
// => [   [ 1, 4, 7 ],
//        [ 2, 5, 8 ],
//        [ 3, 6, 9 ]   ]