wonka/lib/js/src/operators/wonka_operator_takeWhile.js

A fast push & pull stream library for Reason, loosely following the [callbag spec](https://github.com/callbag/callbag)

'use strict';

var Block = require("bs-platform/lib/js/block.js");
var Curry = require("bs-platform/lib/js/curry.js");
var Wonka_helpers = require("../wonka_helpers.js");

function takeWhile(f) {
  return (function (source) {
      return (function (sink) {
          var ended = /* record */[/* contents */false];
          var talkback = /* record */[/* contents */Wonka_helpers.talkbackPlaceholder];
          Curry._1(source, (function (signal) {
                  if (typeof signal === "number") {
                    if (ended[0]) {
                      return /* () */0;
                    } else {
                      ended[0] = true;
                      return sink(/* End */0);
                    }
                  } else if (signal.tag) {
                    if (ended[0]) {
                      return /* () */0;
                    } else if (f(signal[0])) {
                      return sink(signal);
                    } else {
                      ended[0] = true;
                      sink(/* End */0);
                      return talkback[0](/* Close */1);
                    }
                  } else {
                    talkback[0] = signal[0];
                    return sink(signal);
                  }
                }));
          return sink(/* Start */Block.__(0, [(function (signal) {
                            if (ended[0]) {
                              return 0;
                            } else if (signal) {
                              ended[0] = true;
                              return talkback[0](/* Close */1);
                            } else {
                              return talkback[0](/* Pull */0);
                            }
                          })]));
        });
    });
}

exports.takeWhile = takeWhile;
/* No side effect */