curry-this/curry.js

Currying made simple

'use strict';

Object.defineProperty(exports, '__esModule', {
  value: true
});
// istanbul ignore next

function _toConsumableArray(arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i]; return arr2; } else { return Array.from(arr); } }

var arity = require('util-arity');

exports['default'] = function (_ref) {
  var placeholder = _ref.placeholder;

  var merge = function merge(dest, origin) {
    var newArgs = dest.map(function (i) {
      var elem = i;
      if (i === placeholder && origin[0]) {
        elem = origin.shift();
      }
      return elem;
    });

    return newArgs.concat(origin);
  };

  var actualLength = function actualLength(arr) {
    return arr.reduce(function (len, curr) {
      return curr === placeholder ? len : len + 1;
    }, 0);
  };

  var containsPlaceholder = function containsPlaceholder(args) {
    return args.some(function (arg) {
      return arg === placeholder;
    });
  };

  function curry() {
    var fn = this;

    for (var _len = arguments.length, initialArgs = Array(_len), _key = 0; _key < _len; _key++) {
      initialArgs[_key] = arguments[_key];
    }

    var len = containsPlaceholder(initialArgs) ? initialArgs.length : fn.length;

    var _curry = function _curry() {
      for (var _len2 = arguments.length, args = Array(_len2), _key2 = 0; _key2 < _len2; _key2++) {
        args[_key2] = arguments[_key2];
      }

      var f = function f() {
        for (var _len3 = arguments.length, newArgs = Array(_len3), _key3 = 0; _key3 < _len3; _key3++) {
          newArgs[_key3] = arguments[_key3];
        }

        var concatedArgs = merge(args, newArgs);
        return actualLength(concatedArgs) >= len ? fn.apply(undefined, _toConsumableArray(concatedArgs.slice(0, len))) : _curry.apply(undefined, _toConsumableArray(concatedArgs));
      };

      return arity(len - actualLength(args), f);
    };

    return _curry.apply(undefined, initialArgs)();
  }
  return curry;
};

module.exports = exports['default'];