fmrs

filter/find, map, reduce, sort

fmrs is a collection of utility functions that filter/find, map, reduce, and sort JavaScript primitives and built-ins between each other.

For example:

• Mapping the boolean true to a string would be 'true'.
• Reducing the entries [['key', 'value']] to a record would be { key: 'value' }.
• Sorting the values 1 and 2 would be -1.

Filters and finders

• boolean (value is boolean)
  • arr.every(isBoolean)
  • arr.filter(filterByBoolean)
  • arr.find(findBoolean)
• defined
  • arr.every(isDefined)
  • arr.filter(filterByDefined)
  • arr.find(findDefined)
• number (value is number)
  • arr.every(isNumber)
  • arr.filter(filterByNumber)
  • arr.find(findNumber)
• object (value is object)
  • arr.every(isObject)
  • arr.filter(filterByObject)
  • arr.find(findObject)
• record (value is Record<number | string | symbol, unknown>)
  • arr.every(isRecord)
  • arr.filter(filterByRecord)
  • arr.find(findRecord)
• string
  • arr.every(isString)
  • arr.filter(filterByString)
  • arr.find(findString)
• undefined (value is undefined)
  • arr.every(isUndefined)
  • arr.filter(filterByUndefined)
  • arr.find(findUndefined)

Mappers

from	to	example
boolean	number	[false, true].map(mapBooleanToNumber)
entries	Record ({})	mapEntriesToRecord([['key', 'value']])
entry	key	mapEntryToKey(['key', 'value'])
entry	value	mapEntryToValue(['key', 'value'])
Map	entries	mapMapToEntries(new Map())
Map	Record ({})	mapMapToRecord(new Map())
unknown	Error	arr.map(mapToError)
unknown	index	arr.map(mapToIndex)
unknown	string	arr.map(mapToString)

Reducers

from	to	example
entries	Record ({})	Object.entries(record).reduce(reduceEntriesToRecord, {})

Sorters

items	example
Array	arrOfArrs.sort(sortByIndex(0))
number	arr.sort(sortNumbers)
string	arr.sort(sortStrings)
unknown	arr.sort(sort)

Utilities

function	example
is	['a', 'b'].filter(is('a'))
isNot	['a', 'b'].filter(isNot('a'))
not	['a', 'b'].filter(not(is('a')))