COPYING

This file is part of AMBJS.

AMBJS is free software: you can redistribute it and/or modify it under
the terms of the Lesser GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.

AMBJS is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the Lesser GNU General Public
License for more details.

You should have received a copy of the Lesser GNU General Public
License along with AMBJS. See the files COPYING.LESSER and COPYING. If
these files are not present, see http://www.gnu.org/licenses/

LICENSE

Copyright (C) 2011 Patrick Logan

Distributed under the terms of the GNU LESSER GENERAL PUBLIC LICENSE, Version 3.

See also http://www.gnu.org/licenses/

CONTACT

patrickdlogan uses gmail

VERSION

v0.1.0

Initial version.

FUNCTIONALITY

AMBJS is an Javascript implementation of a variation of John
McCarthy's AMB operator.

See the PDF of his 1963 "A Basis for a Mathematical Theory of
Computation" at http://www-formal.stanford.edu/jmc/basis1.pdf

See also http://mitpress.mit.edu/sicp/full-text/sicp/book/node89.html

Traditionally AMB takes an zero or more expressions and
nondeterministically chooses to evaluate one of them. (AMB stands for
"ambiguous")

If the chosen expression "fails" (see below) then AMB will attempt to
"backtrack" and choose from the remaining expressions.

AMB applied to zero expressions always "fails".

This Javascript implementation works somewhat differently. AMB takes
three arguments:

An array of values; a function of two arguments; and a "failure value".

AMB chooses nondeterministically one of the values from the array and
applies that to the given function. The second argument to the
function is a "fail" function.

The given function should return a value indicating the successful
application of the chosen value. AMB then returns that value to its
caller.

If the function "fails" then it should return the result of calling
its second argument, the "fail" function.

AMB will return first successful function result to its caller. If
every application of the function fails, then AMB will return the
given "failure value" to its caller.

See the qunit tests in this distribution for examples. See also <the
blog post>.