pi-generator.js - mozsearch

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/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

//-----------------------------------------------------------------------------

var summary = "A (slow) generator of pi";

var actual, expect;

printStatus(summary);

/**************

 * BEGIN TEST *

 **************/

function* pi()

  var val = 0;

  var curr = 1;

  var isNeg = false;

  while (true)

    if (isNeg)

      yield val -= 4/curr;

    else

      yield val += 4/curr;

    curr += 2;

    isNeg = !isNeg;

var failed = false;

var it = pi();

var vals =

[4,

   4 - 4/3,

   4 - 4/3 + 4/5,

   4 - 4/3 + 4/5 - 4/7];

try

  for (var i = 0, sz = vals.length; i < sz; i++)

    if (it.next().value != vals[i])

      throw vals[i];

catch (e)

  failed = e;

expect = false;

actual = failed;

reportCompare(expect, actual, summary);