$.partial.js 769 Bytes
'use strict';
var path      = require('./$.path')
  , invoke    = require('./$.invoke')
  , aFunction = require('./$.a-function');
module.exports = function(/* ...pargs */){
  var fn     = aFunction(this)
    , length = arguments.length
    , pargs  = Array(length)
    , i      = 0
    , _      = path._
    , holder = false;
  while(length > i)if((pargs[i] = arguments[i++]) === _)holder = true;
  return function(/* ...args */){
    var that  = this
      , $$    = arguments
      , $$len = $$.length
      , j = 0, k = 0, args;
    if(!holder && !$$len)return invoke(fn, pargs, that);
    args = pargs.slice();
    if(holder)for(;length > j; j++)if(args[j] === _)args[j] = $$[k++];
    while($$len > k)args.push($$[k++]);
    return invoke(fn, args, that);
  };
};