csp.js

"use strict";

require = (function e(t, n, r) {
  function s(o, u) {
    if (!n[o]) {
      if (!t[o]) {
        var a = typeof require == "function" && require;if (!u && a) return a(o, !0);if (i) return i(o, !0);throw new Error("Cannot find module '" + o + "'");
      }var f = n[o] = { exports: {} };t[o][0].call(f.exports, function (e) {
        var n = t[o][1][e];return s(n ? n : e);
      }, f, f.exports, e, t, n, r);
    }return n[o].exports;
  }var i = typeof require == "function" && require;for (var o = 0; o < r.length; o++) s(r[o]);return s;
})({ 1: [function (require, module, exports) {
    "use strict";

    var buffers = require("./impl/buffers");
    var channels = require("./impl/channels");
    var select = require("./impl/select");
    var process = require("./impl/process");
    var timers = require("./impl/timers");

    function spawn(gen, returnChannel) {
      if (returnChannel) {
        var ch = channels.chan(buffers.fixed(1));
        (new process.Process(gen, function (value) {
          process.put_then_callback(ch, value, function (ok) {
            ch.close();
          });
        })).run();
        return ch;
      } else {
        (new process.Process(gen)).run();
        return null;
      }
    };

    function go(f, args, returnChannel) {
      var gen = f.apply(null, args);
      return spawn(gen, returnChannel);
    };

    function chan(bufferOrNumber) {
      var buf;
      if (bufferOrNumber === 0) {
        bufferOrNumber = null;
      }
      if (typeof bufferOrNumber === "number") {
        buf = buffers.fixed(bufferOrNumber);
      } else {
        buf = bufferOrNumber;
      }
      return channels.chan(buf);
    };


    module.exports = {
      buffers: {
        fixed: buffers.fixed,
        dropping: buffers.dropping,
        sliding: buffers.sliding
      },

      spawn: spawn,
      go: go,
      chan: chan,
      DEFAULT: select.DEFAULT,
      CLOSED: channels.CLOSED,

      put: process.put,
      take: process.take,
      sleep: process.sleep,
      alts: process.alts,
      putAsync: process.put_then_callback,
      takeAsync: process.take_then_callback,

      timeout: timers.timeout
    };
  }, { "./impl/buffers": 5, "./impl/channels": 6, "./impl/process": 8, "./impl/select": 9, "./impl/timers": 10 }], i2jwt0: [function (require, module, exports) {
    "use strict";

    var csp = require("./csp.core");
    var operations = require("./csp.operations");

    csp.operations = operations;

    module.exports = csp;
  }, { "./csp.core": 1, "./csp.operations": 4 }], csp: [function (require, module, exports) {
    module.exports = require("i2jwt0");
  }, {}], 4: [function (require, module, exports) {
    var mapcat = regeneratorRuntime.mark(function mapcat(f, src, dst) {
      var value, seq, length, i;
      return regeneratorRuntime.wrap(function mapcat$(_context2) {
        while (true) switch (_context2.prev = _context2.next) {
          case 0:
            if (!true) {
              _context2.next = 22;
              break;
            }
            _context2.next = 3;
            return take(src);
          case 3: value = _context2.sent;
            if (!(value === CLOSED)) {
              _context2.next = 9;
              break;
            }
            dst.close();
            return _context2.abrupt("break", 22);
          case 9: seq = f(value);
            length = seq.length;
            i = 0;
          case 12:
            if (!(i < length)) {
              _context2.next = 18;
              break;
            }
            _context2.next = 15;
            return put(dst, seq[i]);
          case 15: i++;
            _context2.next = 12;
            break;
          case 18:
            if (!dst.is_closed()) {
              _context2.next = 20;
              break;
            }
            return _context2.abrupt("break", 22);
          case 20: _context2.next = 0;
            break;
          case 22:
          case "end": return _context2.stop();
        }
      }, mapcat, this);
    });

    "use strict";

    var Box = require("./impl/channels").Box;

    var csp = require("./csp.core"), go = csp.go, take = csp.take, put = csp.put, takeAsync = csp.takeAsync, putAsync = csp.putAsync, alts = csp.alts, chan = csp.chan, CLOSED = csp.CLOSED;


    function noOp(v) {}

    function mapFrom(f, ch) {
      return {
        is_closed: function () {
          return ch.is_closed();
        },
        close: function () {
          ch.close();
        },
        _put: function (value, handler) {
          return ch._put(value, handler);
        },
        _take: function (handler) {
          var result = ch._take({
            is_active: function () {
              return handler.is_active();
            },
            commit: function () {
              var take_cb = handler.commit();
              return function (value) {
                return take_cb(value === CLOSED ? CLOSED : f(value));
              };
            }
          });
          if (result) {
            var value = result.value;
            return new Box(value === CLOSED ? CLOSED : f(value));
          } else {
            return null;
          }
        }
      };
    }

    function mapInto(f, ch) {
      return {
        is_closed: function () {
          return ch.is_closed();
        },
        close: function () {
          ch.close();
        },
        _put: function (value, handler) {
          return ch._put(f(value), handler);
        },
        _take: function (handler) {
          return ch._take(handler);
        }
      };
    }

    function filterFrom(p, ch, bufferOrN) {
      var out = chan(bufferOrN);
      go(regeneratorRuntime.mark(function _callee() {
        var value;
        return regeneratorRuntime.wrap(function _callee$(_context) {
          while (true) switch (_context.prev = _context.next) {
            case 0:
              if (!true) {
                _context.next = 12;
                break;
              }
              _context.next = 3;
              return take(ch);
            case 3: value = _context.sent;
              if (!(value === CLOSED)) {
                _context.next = 7;
                break;
              }
              out.close();
              return _context.abrupt("break", 12);
            case 7:
              if (!p(value)) {
                _context.next = 10;
                break;
              }
              _context.next = 10;
              return put(out, value);
            case 10: _context.next = 0;
              break;
            case 12:
            case "end": return _context.stop();
          }
        }, _callee, this);
      }));
      return out;
    }

    function filterInto(p, ch) {
      return {
        is_closed: function () {
          return ch.is_closed();
        },
        close: function () {
          ch.close();
        },
        _put: function (value, handler) {
          if (p(value)) {
            return ch._put(value, handler);
          } else {
            return new Box(!ch.is_closed());
          }
        },
        _take: function (handler) {
          return ch._take(handler);
        }
      };
    }

    function removeFrom(p, ch) {
      return filterFrom(function (value) {
        return !p(value);
      }, ch);
    }

    function removeInto(p, ch) {
      return filterInto(function (value) {
        return !p(value);
      }, ch);
    }

    function mapcatFrom(f, ch, bufferOrN) {
      var out = chan(bufferOrN);
      go(mapcat, [f, ch, out]);
      return out;
    }

    function mapcatInto(f, ch, bufferOrN) {
      var src = chan(bufferOrN);
      go(mapcat, [f, src, ch]);
      return src;
    }

    function pipe(src, dst, keepOpen) {
      go(regeneratorRuntime.mark(function _callee2() {
        var value;
        return regeneratorRuntime.wrap(function _callee2$(_context3) {
          while (true) switch (_context3.prev = _context3.next) {
            case 0:
              if (!true) {
                _context3.next = 13;
                break;
              }
              _context3.next = 3;
              return take(src);
            case 3: value = _context3.sent;
              if (!(value === CLOSED)) {
                _context3.next = 7;
                break;
              }
              if (!keepOpen) {
                dst.close();
              }
              return _context3.abrupt("break", 13);
            case 7: _context3.next = 9;
              return put(dst, value);
            case 9:
              if (_context3.sent) {
                _context3.next = 11;
                break;
              }
              return _context3.abrupt("break", 13);
            case 11: _context3.next = 0;
              break;
            case 13:
            case "end": return _context3.stop();
          }
        }, _callee2, this);
      }));
      return dst;
    }

    function split(p, ch, trueBufferOrN, falseBufferOrN) {
      var tch = chan(trueBufferOrN);
      var fch = chan(falseBufferOrN);
      go(regeneratorRuntime.mark(function _callee3() {
        var value;
        return regeneratorRuntime.wrap(function _callee3$(_context4) {
          while (true) switch (_context4.prev = _context4.next) {
            case 0:
              if (!true) {
                _context4.next = 12;
                break;
              }
              _context4.next = 3;
              return take(ch);
            case 3: value = _context4.sent;
              if (!(value === CLOSED)) {
                _context4.next = 8;
                break;
              }
              tch.close();
              fch.close();
              return _context4.abrupt("break", 12);
            case 8: _context4.next = 10;
              return put(p(value) ? tch : fch, value);
            case 10: _context4.next = 0;
              break;
            case 12:
            case "end": return _context4.stop();
          }
        }, _callee3, this);
      }));
      return [tch, fch];
    }

    function reduce(f, init, ch) {
      return go(regeneratorRuntime.mark(function _callee4() {
        var result, value;
        return regeneratorRuntime.wrap(function _callee4$(_context5) {
          while (true) switch (_context5.prev = _context5.next) {
            case 0: result = init;
            case 1:
              if (!true) {
                _context5.next = 12;
                break;
              }
              _context5.next = 4;
              return take(ch);
            case 4: value = _context5.sent;
              if (!(value === CLOSED)) {
                _context5.next = 9;
                break;
              }
              return _context5.abrupt("return", result);
            case 9:
              result = f(result, value);
            case 10: _context5.next = 1;
              break;
            case 12:
            case "end": return _context5.stop();
          }
        }, _callee4, this);
      }), [], true);
    }

    function onto(ch, coll, keepOpen) {
      return go(regeneratorRuntime.mark(function _callee5() {
        var length, i;
        return regeneratorRuntime.wrap(function _callee5$(_context6) {
          while (true) switch (_context6.prev = _context6.next) {
            case 0: length = coll.length;
              i = 0;
            case 2:
              if (!(i < length)) {
                _context6.next = 8;
                break;
              }
              _context6.next = 5;
              return put(ch, coll[i]);
            case 5: i++;
              _context6.next = 2;
              break;
            case 8:
              if (!keepOpen) {
                ch.close();
              }
            case 9:
            case "end": return _context6.stop();
          }
        }, _callee5, this);
      }));
    }

    // TODO: Bounded?
    function fromColl(coll) {
      var ch = chan(coll.length);
      onto(ch, coll);
      return ch;
    }

    function map(f, chs, bufferOrN) {
      var out = chan(bufferOrN);
      var length = chs.length;
      // Array holding 1 round of values
      var values = new Array(length);
      // TODO: Not sure why we need a size-1 buffer here
      var dchan = chan(1);
      // How many more items this round
      var dcount;
      // put callbacks for each channel
      var dcallbacks = new Array(length);
      for (var i = 0; i < length; i++) {
        dcallbacks[i] = (function (i) {
          return function (value) {
            values[i] = value;
            dcount--;
            if (dcount === 0) {
              putAsync(dchan, values.slice(0), noOp);
            }
          };
        }(i));
      }
      go(regeneratorRuntime.mark(function _callee6() {
        var i, values;
        return regeneratorRuntime.wrap(function _callee6$(_context7) {
          while (true) switch (_context7.prev = _context7.next) {
            case 0:
              if (!true) {
                _context7.next = 18;
                break;
              }
              dcount = length;
              // We could just launch n goroutines here, but for effciency we
              // don't
              for (i = 0; i < length; i++) {
                try {
                  takeAsync(chs[i], dcallbacks[i]);
                } catch (e) {
                  // FIX: Hmm why catching here?
                  dcount--;
                }
              }
              _context7.next = 5;
              return take(dchan);
            case 5: values = _context7.sent;
              i = 0;
            case 7:
              if (!(i < length)) {
                _context7.next = 14;
                break;
              }
              if (!(values[i] === CLOSED)) {
                _context7.next = 11;
                break;
              }
              out.close();
              return _context7.abrupt("return");
            case 11: i++;
              _context7.next = 7;
              break;
            case 14: _context7.next = 16;
              return put(out, f.apply(null, values));
            case 16: _context7.next = 0;
              break;
            case 18:
            case "end": return _context7.stop();
          }
        }, _callee6, this);
      }));
      return out;
    }

    function merge(chs, bufferOrN) {
      var out = chan(bufferOrN);
      var actives = chs.slice(0);
      go(regeneratorRuntime.mark(function _callee7() {
        var r, value, i;
        return regeneratorRuntime.wrap(function _callee7$(_context8) {
          while (true) switch (_context8.prev = _context8.next) {
            case 0:
              if (!true) {
                _context8.next = 15;
                break;
              }
              if (!(actives.length === 0)) {
                _context8.next = 3;
                break;
              }
              return _context8.abrupt("break", 15);
            case 3: _context8.next = 5;
              return alts(actives);
            case 5: r = _context8.sent;
              value = r.value;
              if (!(value === CLOSED)) {
                _context8.next = 11;
                break;
              }
              i = actives.indexOf(r.channel);
              actives.splice(i, 1);
              return _context8.abrupt("continue", 0);
            case 11: _context8.next = 13;
              return put(out, value);
            case 13: _context8.next = 0;
              break;
            case 15:
              out.close();
            case 16:
            case "end": return _context8.stop();
          }
        }, _callee7, this);
      }));
      return out;
    }

    function into(coll, ch) {
      var result = coll.slice(0);
      return reduce(function (result, item) {
        result.push(item);
        return result;
      }, result, ch);
    }

    function takeN(n, ch, bufferOrN) {
      var out = chan(bufferOrN);
      go(regeneratorRuntime.mark(function _callee8() {
        var i, value;
        return regeneratorRuntime.wrap(function _callee8$(_context9) {
          while (true) switch (_context9.prev = _context9.next) {
            case 0: i = 0;
            case 1:
              if (!(i < n)) {
                _context9.next = 12;
                break;
              }
              _context9.next = 4;
              return take(ch);
            case 4: value = _context9.sent;
              if (!(value === CLOSED)) {
                _context9.next = 7;
                break;
              }
              return _context9.abrupt("break", 12);
            case 7: _context9.next = 9;
              return put(out, value);
            case 9: i++;
              _context9.next = 1;
              break;
            case 12:
              out.close();
            case 13:
            case "end": return _context9.stop();
          }
        }, _callee8, this);
      }));
      return out;
    }

    var NOTHING = {};

    function unique(ch, bufferOrN) {
      var out = chan(bufferOrN);
      var last = NOTHING;
      go(regeneratorRuntime.mark(function _callee9() {
        var value;
        return regeneratorRuntime.wrap(function _callee9$(_context10) {
          while (true) switch (_context10.prev = _context10.next) {
            case 0:
              if (!true) {
                _context10.next = 13;
                break;
              }
              _context10.next = 3;
              return take(ch);
            case 3: value = _context10.sent;
              if (!(value === CLOSED)) {
                _context10.next = 6;
                break;
              }
              return _context10.abrupt("break", 13);
            case 6:
              if (!(value === last)) {
                _context10.next = 8;
                break;
              }
              return _context10.abrupt("continue", 0);
            case 8:
              last = value;
              _context10.next = 11;
              return put(out, value);
            case 11: _context10.next = 0;
              break;
            case 13:
              out.close();
            case 14:
            case "end": return _context10.stop();
          }
        }, _callee9, this);
      }));
      return out;
    }

    function partitionBy(f, ch, bufferOrN) {
      var out = chan(bufferOrN);
      var part = [];
      var last = NOTHING;
      go(regeneratorRuntime.mark(function _callee10() {
        var value, newItem;
        return regeneratorRuntime.wrap(function _callee10$(_context11) {
          while (true) switch (_context11.prev = _context11.next) {
            case 0:
              if (!true) {
                _context11.next = 23;
                break;
              }
              _context11.next = 3;
              return take(ch);
            case 3: value = _context11.sent;
              if (!(value === CLOSED)) {
                _context11.next = 12;
                break;
              }
              if (!(part.length > 0)) {
                _context11.next = 8;
                break;
              }
              _context11.next = 8;
              return put(out, part);
            case 8:
              out.close();
              return _context11.abrupt("break", 23);
            case 12: newItem = f(value);
              if (!(newItem === last || last === NOTHING)) {
                _context11.next = 17;
                break;
              }
              part.push(value);
              _context11.next = 20;
              break;
            case 17: _context11.next = 19;
              return put(out, part);
            case 19:
              part = [value];
            case 20:
              last = newItem;
            case 21: _context11.next = 0;
              break;
            case 23:
            case "end": return _context11.stop();
          }
        }, _callee10, this);
      }));
      return out;
    }

    function partition(n, ch, bufferOrN) {
      var out = chan(bufferOrN);
      go(regeneratorRuntime.mark(function _callee11() {
        var part, i, value;
        return regeneratorRuntime.wrap(function _callee11$(_context12) {
          while (true) switch (_context12.prev = _context12.next) {
            case 0:
              if (!true) {
                _context12.next = 21;
                break;
              }
              part = new Array(n);
              i = 0;
            case 3:
              if (!(i < n)) {
                _context12.next = 17;
                break;
              }
              _context12.next = 6;
              return take(ch);
            case 6: value = _context12.sent;
              if (!(value === CLOSED)) {
                _context12.next = 13;
                break;
              }
              if (!(i > 0)) {
                _context12.next = 11;
                break;
              }
              _context12.next = 11;
              return put(out, part.slice(0, i));
            case 11:
              out.close();
              return _context12.abrupt("return");
            case 13:
              part[i] = value;
            case 14: i++;
              _context12.next = 3;
              break;
            case 17: _context12.next = 19;
              return put(out, part);
            case 19: _context12.next = 0;
              break;
            case 21:
            case "end": return _context12.stop();
          }
        }, _callee11, this);
      }));
      return out;
    }

    module.exports = {
      mapFrom: mapFrom,
      mapInto: mapInto,
      filterFrom: filterFrom,
      filterInto: filterInto,
      removeFrom: removeFrom,
      removeInto: removeInto,
      mapcatFrom: mapcatFrom,
      mapcatInto: mapcatInto,

      pipe: pipe,
      split: split,
      reduce: reduce,
      onto: onto,
      fromColl: fromColl,

      map: map,
      merge: merge,
      into: into,
      take: takeN,
      unique: unique,
      partition: partition,
      partitionBy: partitionBy
    };


    // Possible "fluid" interfaces:

    // thread(
    //   [fromColl, [1, 2, 3, 4]],
    //   [mapFrom, inc],
    //   [into, []]
    // )

    // thread(
    //   [fromColl, [1, 2, 3, 4]],
    //   [mapFrom, inc, _],
    //   [into, [], _]
    // )

    // wrap()
    //   .fromColl([1, 2, 3, 4])
    //   .mapFrom(inc)
    //   .into([])
    //   .unwrap();
  }, { "./csp.core": 1, "./impl/channels": 6 }], 5: [function (require, module, exports) {
    "use strict";

    // TODO: Consider EmptyError & FullError to avoid redundant bound
    // checks, to improve performance (may need benchmarks)

    function acopy(src, src_start, dst, dst_start, length) {
      var count = 0;
      while (true) {
        if (count >= length) {
          break;
        }
        dst[dst_start + count] = src[src_start + count];
        count++;
      }
    }

    var EMPTY = {
      toString: function () {
        return "[object EMPTY]";
      }
    };

    var RingBuffer = function (head, tail, length, array) {
      this.length = length;
      this.array = array;
      this.head = head;
      this.tail = tail;
    };

    // Internal method, callers must do bound check
    RingBuffer.prototype._unshift = function (item) {
      var array = this.array;
      var head = this.head;
      array[head] = item;
      this.head = (head + 1) % array.length;
      this.length++;
    };

    RingBuffer.prototype._resize = function () {
      var array = this.array;
      var new_length = 2 * array.length;
      var new_array = new Array(new_length);
      var head = this.head;
      var tail = this.tail;
      var length = this.length;
      if (tail < head) {
        acopy(array, tail, new_array, 0, length);
        this.tail = 0;
        this.head = length;
        this.array = new_array;
      } else if (tail > head) {
        acopy(array, tail, new_array, 0, array.length - tail);
        acopy(array, 0, new_array, array.length - tail, head);
        this.tail = 0;
        this.head = length;
        this.array = new_array;
      } else if (tail === head) {
        this.tail = 0;
        this.head = 0;
        this.array = new_array;
      }
    };

    RingBuffer.prototype.unbounded_unshift = function (item) {
      if (this.length + 1 === this.array.length) {
        this._resize();
      }
      this._unshift(item);
    };

    RingBuffer.prototype.pop = function () {
      if (this.length === 0) {
        return EMPTY;
      }
      var array = this.array;
      var tail = this.tail;
      var item = array[tail];
      array[tail] = null;
      this.tail = (tail + 1) % array.length;
      this.length--;
      return item;
    };

    RingBuffer.prototype.cleanup = function (predicate) {
      var length = this.length;
      for (var i = 0; i < length; i++) {
        var item = this.pop();
        if (predicate(item)) {
          this._unshift(item);
        }
      }
    };


    var FixedBuffer = function (buf, n) {
      this.buf = buf;
      this.n = n;
    };

    FixedBuffer.prototype.is_full = function () {
      return this.buf.length == this.n;
    };

    FixedBuffer.prototype.remove = function () {
      return this.buf.pop();
    };

    FixedBuffer.prototype.add = function (item) {
      if (this.is_full()) {
        throw new Error("Can't add to a full buffer");
      }
      this.buf._unshift(item);
    };

    FixedBuffer.prototype.count = function () {
      return this.buf.length;
    };


    var DroppingBuffer = function (buf, n) {
      this.buf = buf;
      this.n = n;
    };

    DroppingBuffer.prototype.is_full = function () {
      return false;
    };

    DroppingBuffer.prototype.remove = function () {
      return this.buf.pop();
    };

    DroppingBuffer.prototype.add = function (item) {
      if (this.buf.length < this.n) {
        this.buf._unshift(item);
      }
    };

    DroppingBuffer.prototype.count = function () {
      return this.buf.length;
    };


    var SlidingBuffer = function (buf, n) {
      this.buf = buf;
      this.n = n;
    };

    SlidingBuffer.prototype.is_full = function () {
      return false;
    };

    SlidingBuffer.prototype.remove = function () {
      return this.buf.pop();
    };

    SlidingBuffer.prototype.add = function (item) {
      if (this.buf.length === this.n) {
        this.buf.pop();
      }
      this.buf._unshift(item);
    };

    SlidingBuffer.prototype.count = function () {
      return this.buf.length;
    };


    var ring = exports.ring = function ring_buffer(n) {
      return new RingBuffer(0, 0, 0, new Array(n));
    };

    exports.fixed = function fixed_buffer(n) {
      return new FixedBuffer(ring(n), n);
    };

    exports.dropping = function dropping_buffer(n) {
      return new DroppingBuffer(ring(n), n);
    };

    exports.sliding = function sliding_buffer(n) {
      return new SlidingBuffer(ring(n), n);
    };

    exports.EMPTY = EMPTY;
  }, {}], 6: [function (require, module, exports) {
    "use strict";

    var buffers = require("./buffers");
    var dispatch = require("./dispatch");

    var MAX_DIRTY = 64;
    var MAX_QUEUE_SIZE = 1024;

    var CLOSED = null;

    var Box = function (value) {
      this.value = value;
    };

    var PutBox = function (handler, value) {
      this.handler = handler;
      this.value = value;
    };

    var Channel = function (takes, puts, buf) {
      this.buf = buf;
      this.takes = takes;
      this.puts = puts;

      this.dirty_takes = 0;
      this.dirty_puts = 0;
      this.closed = false;
    };

    Channel.prototype._put = function (value, handler) {
      if (value === CLOSED) {
        throw new Error("Cannot put CLOSED on a channel.");
      }

      if (this.closed || !handler.is_active()) {
        return new Box(!this.closed);
      }

      while (true) {
        var taker = this.takes.pop();
        if (taker !== buffers.EMPTY) {
          if (taker.is_active()) {
            var callback = taker.commit();
            handler.commit();
            dispatch.run(function () {
              callback(value);
            });
            return new Box(true);
          } else {
            continue;
          }
        } else {
          if (this.buf && !this.buf.is_full()) {
            handler.commit();
            this.buf.add(value);
            return new Box(true);
          } else {
            if (this.dirty_puts > MAX_DIRTY) {
              this.puts.cleanup(function (putter) {
                return putter.handler.is_active();
              });
              this.dirty_puts = 0;
            } else {
              this.dirty_puts++;
            }
            if (this.puts.length >= MAX_QUEUE_SIZE) {
              throw new Error("No more than " + MAX_QUEUE_SIZE + " pending puts are allowed on a single channel.");
            }
            this.puts.unbounded_unshift(new PutBox(handler, value));
          }
        }
        break;
      }

      return null;
    };

    Channel.prototype._take = function (handler) {
      if (!handler.is_active()) {
        return null;
      }

      if (this.buf && this.buf.count() > 0) {
        handler.commit();
        return new Box(this.buf.remove());
      }

      while (true) {
        var putter = this.puts.pop();
        if (putter !== buffers.EMPTY) {
          var put_handler = putter.handler;
          if (put_handler.is_active()) {
            handler.commit();
            var callback = put_handler.commit();
            dispatch.run(function () {
              callback(true);
            });
            return new Box(putter.value);
          } else {
            continue;
          }
        } else {
          if (this.closed) {
            handler.commit();
            return new Box(CLOSED);
          } else {
            if (this.dirty_takes > MAX_DIRTY) {
              this.takes.cleanup(function (handler) {
                return handler.is_active();
              });
              this.dirty_takes = 0;
            } else {
              this.dirty_takes++;
            }
            if (this.takes.length >= MAX_QUEUE_SIZE) {
              throw new Error("No more than " + MAX_QUEUE_SIZE + " pending takes are allowed on a single channel.");
            }
            this.takes.unbounded_unshift(handler);
          }
        }
        break;
      }

      return null;
    };

    Channel.prototype.close = function () {
      if (this.closed) {
        return;
      }
      this.closed = true;
      while (true) {
        var taker = this.takes.pop();
        if (taker === buffers.EMPTY) {
          break;
        }
        if (taker.is_active()) {
          var callback = taker.commit();
          dispatch.run(function () {
            callback(CLOSED);
          });
        }
      }
      // TODO: Tests
      while (true) {
        var putter = this.puts.pop();
        if (putter === buffers.EMPTY) {
          break;
        }
        if (putter.handler.is_active()) {
          var put_callback = putter.handler.commit();
          dispatch.run(function () {
            put_callback(false);
          });
        }
      }
    };


    Channel.prototype.is_closed = function () {
      return this.closed;
    };


    exports.chan = function (buf) {
      return new Channel(buffers.ring(32), buffers.ring(32), buf);
    };

    exports.Box = Box;

    exports.CLOSED = CLOSED;
  }, { "./buffers": 5, "./dispatch": 7 }], 7: [function (require, module, exports) {
    "use strict";

    // TODO: Use process.nextTick if it's available since it's more
    // efficient
    // http://howtonode.org/understanding-process-next-tick
    // Maybe we don't even need to queue ourselves in that case?

    // XXX: But http://blog.nodejs.org/2013/03/11/node-v0-10-0-stable/
    // Looks like it will blow up the stack (or is that just about
    // pre-empting IO (but that's already bad enough IMO)?)

    // Looks like
    // http://nodejs.org/api/process.html#process_process_nexttick_callback
    // is the equivalent of our TASK_BATCH_SIZE

    var buffers = require("./buffers");

    var TASK_BATCH_SIZE = 1024;

    var tasks = buffers.ring(32);
    var running = false;
    var queued = false;

    var queue_dispatcher;

    function process_messages() {
      running = true;
      queued = false;
      var count = 0;
      while (true) {
        var task = tasks.pop();
        if (task === buffers.EMPTY) {
          break;
        }
        // TODO: Don't we need a try/finally here?
        task();
        if (count >= TASK_BATCH_SIZE) {
          break;
        }
        count++;
      }
      running = false;
      if (tasks.length > 0) {
        queue_dispatcher();
      }
    }

    if (typeof MessageChannel !== "undefined") {
      var message_channel = new MessageChannel();
      message_channel.port1.onmessage = function (_) {
        process_messages();
      };
      queue_dispatcher = function () {
        if (!(queued && running)) {
          queued = true;
          message_channel.port2.postMessage(0);
        }
      };
    } else if (typeof setImmediate !== "undefined") {
      queue_dispatcher = function () {
        if (!(queued && running)) {
          queued = true;
          setImmediate(process_messages);
        }
      };
    } else {
      queue_dispatcher = function () {
        if (!(queued && running)) {
          queued = true;
          setTimeout(process_messages, 0);
        }
      };
    }

    exports.run = function (f) {
      tasks.unbounded_unshift(f);
      queue_dispatcher();
    };

    exports.queue_delay = function (f, delay) {
      setTimeout(f, delay);
    };
  }, { "./buffers": 5 }], 8: [function (require, module, exports) {
    "use strict";

    var dispatch = require("./dispatch");
    var select = require("./select");

    var FnHandler = function (f) {
      this.f = f;
    };

    FnHandler.prototype.is_active = function () {
      return true;
    };

    FnHandler.prototype.commit = function () {
      return this.f;
    };

    function put_then_callback(channel, value, callback) {
      var result = channel._put(value, new FnHandler(callback));
      if (result) {
        callback(result.value);
      }
    }

    function take_then_callback(channel, callback) {
      var result = channel._take(new FnHandler(callback));
      if (result) {
        callback(result.value);
      }
    }

    var Process = function (gen, onFinish) {
      this.gen = gen;
      this.finished = false;
      this.onFinish = onFinish;
    };

    var Instruction = function (op, data) {
      this.op = op;
      this.data = data;
    };

    var TAKE = "take";
    var PUT = "put";
    var SLEEP = "sleep";
    var ALTS = "alts";

    // TODO FIX XXX: This is a (probably) temporary hack to avoid blowing
    // up the stack, but it means double queueing when the value is not
    // immediately available
    Process.prototype._continue = function (response) {
      var self = this;
      dispatch.run(function () {
        self.run(response);
      });
    };

    Process.prototype._done = function (value) {
      if (!this.finished) {
        this.finished = true;
        var onFinish = this.onFinish;
        if (typeof onFinish === "function") {
          dispatch.run(function () {
            onFinish(value);
          });
        }
      }
    };

    Process.prototype.run = function (response) {
      if (this.finished) {
        return;
      }

      // TODO: Shouldn't we (optionally) stop error propagation here (and
      // signal the error through a channel or something)? Otherwise the
      // uncaught exception will crash some runtimes (e.g. Node)
      var iter = this.gen.next(response);
      if (iter.done) {
        this._done(iter.value);
        return;
      }

      var ins = iter.value;

      if (ins instanceof Instruction) {
        var self = this;
        switch (ins.op) {
          case PUT:
            var data = ins.data;
            put_then_callback(data.channel, data.value, function (ok) {
              self._continue(ok);
            });
            break;

          case TAKE:
            var channel = ins.data;
            take_then_callback(channel, function (value) {
              self._continue(value);
            });
            break;

          case SLEEP:
            var msecs = ins.data;
            dispatch.queue_delay(function () {
              self.run(null);
            }, msecs);
            break;

          case ALTS:
            select.do_alts(ins.data.operations, function (result) {
              self._continue(result);
            }, ins.data.options);
            break;
        }
      } else {
        this._continue(ins);
      }
    };

    function take(channel) {
      return new Instruction(TAKE, channel);
    }

    function put(channel, value) {
      return new Instruction(PUT, {
        channel: channel,
        value: value
      });
    }

    function sleep(msecs) {
      return new Instruction(SLEEP, msecs);
    }

    function alts(operations, options) {
      return new Instruction(ALTS, {
        operations: operations,
        options: options
      });
    }

    exports.put_then_callback = put_then_callback;
    exports.take_then_callback = take_then_callback;
    exports.put = put;
    exports.take = take;
    exports.sleep = sleep;
    exports.alts = alts;

    exports.Process = Process;
  }, { "./dispatch": 7, "./select": 9 }], 9: [function (require, module, exports) {
    "use strict";

    var Box = require("./channels").Box;

    var AltHandler = function (flag, f) {
      this.f = f;
      this.flag = flag;
    };

    AltHandler.prototype.is_active = function () {
      return this.flag.value;
    };

    AltHandler.prototype.commit = function () {
      this.flag.value = false;
      return this.f;
    };

    var AltResult = function (value, channel) {
      this.value = value;
      this.channel = channel;
    };

    function rand_int(n) {
      return Math.floor(Math.random() * (n + 1));
    }

    function random_array(n) {
      var a = new Array(n);
      var i;
      for (i = 0; i < n; i++) {
        a[i] = 0;
      }
      for (i = 1; i < n; i++) {
        var j = rand_int(i);
        a[i] = a[j];
        a[j] = i;
      }
      return a;
    }

    var hasOwnProperty = Object.prototype.hasOwnProperty;

    var DEFAULT = {
      toString: function () {
        return "[object DEFAULT]";
      }
    };

    // TODO: Accept a priority function or something
    exports.do_alts = function (operations, callback, options) {
      var length = operations.length;
      // XXX Hmm
      if (length === 0) {
        throw new Error("Empty alt list");
      }

      var priority = (options && options.priority) ? true : false;
      if (!priority) {
        var indexes = random_array(length);
      }

      var flag = new Box(true);

      for (var i = 0; i < length; i++) {
        var operation = operations[priority ? i : indexes[i]];
        var port, result;
        // XXX Hmm
        if (operation instanceof Array) {
          var value = operation[1];
          port = operation[0];
          result = port._put(value, (function (port) {
            return new AltHandler(flag, function (ok) {
              callback(new AltResult(ok, port));
            });
          })(port));
        } else {
          port = operation;
          result = port._take((function (port) {
            return new AltHandler(flag, function (value) {
              callback(new AltResult(value, port));
            });
          })(port));
        }
        // XXX Hmm
        if (result instanceof Box) {
          callback(new AltResult(result.value, port));
          break;
        }
      }

      if (!(result instanceof Box) && options && hasOwnProperty.call(options, "default")) {
        if (flag.value) {
          flag.value = false;
          callback(new AltResult(options["default"], DEFAULT));
        }
      }
    };

    exports.DEFAULT = DEFAULT;
  }, { "./channels": 6 }], 10: [function (require, module, exports) {
    "use strict";

    var dispatch = require("./dispatch");
    var channels = require("./channels");

    exports.timeout = function timeout_channel(msecs) {
      var chan = channels.chan();
      dispatch.queue_delay(function () {
        chan.close();
      }, msecs);
      return chan;
    };
  }, { "./channels": 6, "./dispatch": 7 }] }, {}, ["i2jwt0"]);