thread-f

thread-f

Clojure style threading of functions in JavaScript.

Inpsired by the threading macros in Clojure.

Usage

Instead of writing

var x = foo(bar(something(whatever(n), 2), {}));

var y = foo(bar({}, something(2, whatever(n))));

write

var threadF = require('thread-f');

var x = threadF.first(n, [
    whatever,
    [something, 2],
    [bar, {}],
    foo
]);



var x = threadF.last(n, [
    whatever,
    [something, 2],
    [bar, {}],
    foo
]);

This makes this chain of functions easier to read and change.

threadFirst will apply each function in the specified order, using the return value as first arguments for the next. threadLast does the same but passes the value as the last argument.

Each entry in the functions array can be either a plain function or an array. If it's an array, the first element will be used as the function and the rest as additional arguments.

Using [foo, 1, 2, 3] as a functions entry for threadF.first will result in calling foo(x, 1, 2, 3) while using it with threadF.last will result in foo(1, 2, 3, x).

For examples, see the tests.

API

thread

threadF.thread(first, value, functions, thisArg)

• first (bool): wether to apply the value as first argument.
• value (any): the value to be threading through the functions
• functions (array): Array of function or arrays, when encountering an array, the first element will be used a s the function, the rest as additional arguments.
• thisArg (any): value that will be bound to each function's this when calling it

first

threadF.first(value, functions, thisArg)

(same as for thread with the first argument bound to true)

last

threadF.last(value, functions, thisArg)

(same as for thread with the first argument bound to false)