forc/lib/utils/pairs.js

Clone of Clojure list comprehension

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = pairs;

var _typeChecks = require('./typeChecks');

var _marked = [pairs].map(regeneratorRuntime.mark);

function pairs(iter) {
  var prev, _iteratorNormalCompletion, _didIteratorError, _iteratorError, _iterator, _step, item;

  return regeneratorRuntime.wrap(function pairs$(_context) {
    while (1) {
      switch (_context.prev = _context.next) {
        case 0:
          prev = undefined;
          _iteratorNormalCompletion = true;
          _didIteratorError = false;
          _iteratorError = undefined;
          _context.prev = 4;
          _iterator = iter[Symbol.iterator]();

        case 6:
          if (_iteratorNormalCompletion = (_step = _iterator.next()).done) {
            _context.next = 18;
            break;
          }

          item = _step.value;

          if ((0, _typeChecks.isUndefined)(prev)) {
            _context.next = 14;
            break;
          }

          _context.next = 11;
          return [prev, item];

        case 11:
          prev = undefined;
          _context.next = 15;
          break;

        case 14:
          prev = item;

        case 15:
          _iteratorNormalCompletion = true;
          _context.next = 6;
          break;

        case 18:
          _context.next = 24;
          break;

        case 20:
          _context.prev = 20;
          _context.t0 = _context['catch'](4);
          _didIteratorError = true;
          _iteratorError = _context.t0;

        case 24:
          _context.prev = 24;
          _context.prev = 25;

          if (!_iteratorNormalCompletion && _iterator.return) {
            _iterator.return();
          }

        case 27:
          _context.prev = 27;

          if (!_didIteratorError) {
            _context.next = 30;
            break;
          }

          throw _iteratorError;

        case 30:
          return _context.finish(27);

        case 31:
          return _context.finish(24);

        case 32:
          if ((0, _typeChecks.isUndefined)(prev)) {
            _context.next = 34;
            break;
          }

          throw new Error('Iterable pairs require an even number of forms (last key was "' + prev + '")');

        case 34:
        case 'end':
          return _context.stop();
      }
    }
  }, _marked[0], this, [[4, 20, 24, 32], [25,, 27, 31]]);
}