node-higher

Higher order functions for functional programming

Composition of ramda and lodash which both offer some similar but different features and paradigms and complementing features that need combining.

higher follows the paradigm of ramda in expecting the data on which to operate on is usually supplied last.

Installation

npm install higher --save

Use

const H = require('higher');
H.unless(_.isUndefined, 'test', test);

Functions

unless

What: Wrapper around ramda unless function that allows for values to be used instead of functions.

Why: Because writing () => { return 'some value'; } all the time is awful.

How: H.unless(_.isNull, 'test', value) (where _ is lodash) will return either value if it's not null or otherwise 'test' string.

ifElse

What: A concrete instance of ramda ifElse function that evaluates the given predicate or value and allows values to be used instead of functions.

Why: Because writing H.isFalsy('replacement value', maybeUndefined && maybeUndefined.someMethod()) all the time is lame and this makes the purpose clearer.

How: H.ifElse(maybeUndefined, MaybeUndefinedClass.someMethod, 'replacement value') (where _ is lodash) will return either 'replacement value or the result of MaybeUndefinedClass.someMethod applied on maybeUndefined.

ifFalsy

What: Wrapper around unless that tests the given value for falsy state.

Why: Because writing (x) => { return !!x; } all the time is tedious.

How: H.ifFalsy('FALSE', '') returns 'FALSE'

ifNull

What: Wrapper around unless that tests the given value for null value.

Why: Because writing unless(_.isNull, ... all the time is tedious.

How: H.ifNull('<null>', null) returns '<null>'

coerceFunction

What: Returns either the given function or function returning the given value.

Why: Because it's useful internally and maybe it will be useful externally.

How: H.coerceFunction(123) will return function returning 123

coerceArray

What: Returns either the given array or the given non-array value within an array.

Why: Because writing x = _.isArray(x) ? x : [x]; destroys neurons and I saw the example in Ramda documentation and loved it.

How: H.coerceArray(123) will return [123]

isNonEmptyString

What: Returns true if and only if the given value is a non-empty string (even if all the characters are whitespaces)

Why: Because writing _.String(value) && !_.isEmpty(value) is bound to make you zombie sooner or later (and I want to avoid it).

How: H.isNonEmptyString('') will return false whereas H.isNonEmptyString(' ') will return true

contains

What: Returns true if the given value is part of the given array.

Why: Because writing _.indexOf(array, value) !== -1 is way too long.

How: H.contains(['a', 'b'], 'c') will return false whereas H.isNonEmptyString(['a', 'b'], 'a') will return true

noopIfNotFunction

What: Returns _.noop if the given value is not a function thus guaranteeing that the returned value is always a function.

Why: Because writing callback = _.isFunction(callback) ? callback : _.noop has been written one too many times in the history of our Universe.

How: H.noopIfNotFunction(undefined) will return _.noop whereas H.noopIfNotFunction(() => undefined) will return () => undefined function.