xbind

Sugar way to adapt the arguments signature of functions.

Usage

var xbind = require('xbind');
var path = require('path');

function arrayify() {
    var ret = [];
    for (var i = 0, len = arguments.length; i < len; i++) {
        ret.push(arguments[i]);
    }
    return ret;
}

console.log(
    '`arrayify` just make an array from arguments',
    arrayify(0,1,2,3)
)
// `arrayify` just make an array from arguments [ 0, 1, 2, 3  ]

console.log(
    'use the first argument',
    xbind(arrayify).xargs(0)(0,1,2,3)
)
// use the first argument [ 0  ]

console.log(
    'use the first argument',
    xbind(arrayify).first()(0,1,2,3)
)
// use the first argument [ 0  ]

console.log(
    'use the last argument',
    xbind(arrayify).last()(0,1,2,3)
)
// use the last argument [ 3  ]

console.log(
    'use the first and third arguments',
    xbind(arrayify).xargs(0,2)(0,1,2,3),
    xbind(arrayify).xargs([0,2])(0,1,2,3)
)
// use the first and third arguments [ 0, 2  ] [ 0, 2  ]

console.log(
    'append arguments 4,5',
    xbind(arrayify).push(4,5)(0,1,2,3)
)
// append arguments 4,5 [ 0, 1, 2, 3, 4, 5  ]

console.log(
    'prepend arguments 4,5',
    xbind(arrayify).unshift(4,5)(0,1,2,3)
)
// prepend arguments 4,5 [ 4, 5, 0, 1, 2, 3  ]

console.log(
    'slice arguments 1,3',
    xbind(arrayify).slice(1,3)(0,1,2,3)
)
// slice arguments 1,3 [ 1, 2  ]

console.log(
    'filter arguments',
    xbind(arrayify).xargs(1,5).filter(Boolean)(0,1,2,3)
)
// filter arguments [ 1  ]

xfn = xbind(fn, ctx)

Return a new function with a xargs property, through which arguments can be changed.

fn

Type: Function, String

Function to be bound. If String, it will be treated as a method name of ctx

ctx

Type: Object Optional

this value of fn when called. If not specified, this will be this of xfn.

operations

xfn.xargs(index1, index2)

Select arguments with index1, index2

xfn.first()

Select the first argument

xfn.last()

Select the last argument

Array methods

You can operate the argument list using .push, .pop, .shift, .unshift, .slice, .splice, .filter, .map, .reduce, as the argument list is Array.

xbind.identity(o)

Just return a function that returns o