Ambjs

the amb operator is an operator that assigns a value to a variable in an ambigous way, i.e.

var v = amb([1,2,3]);

means that v can be either 1 or b or 3.

obviously javascript semantics doesn't support this behaviour, so it has to be expressed in a specific context that, thanks to sweetjs macros can be transformed in javascript.

Install

> npm install -save ambjs
> npm install -save-dev sweetjs

Example code

this is taken from the test suite

ret = require('../lib/ret'),
amb = require('../lib/amb'),
assert = require('../lib/assert'),

var colors = ['red', 'green', 'yellow', 'blue'];
var colorSet = ambBlock {
  var germany = amb(colors);
  var france = amb(colors);
  var italy = amb(colors);
  var swiss = amb(colors);
  var austria = amb(colors);
  var slovenia = amb(colors);

  assert (germany != france);
  assert (germany != swiss);
  assert (germany != austria);
  assert (france != swiss);
  assert (france != italy);
  assert (italy != swiss);
  assert (italy != austria);
  assert (italy != slovenia);
  assert (swiss != austria);
  assert (austria != slovenia);
  
  ret ({
    germany: germany,
    france: france,
    italy: italy,
    swiss: swiss,
    austria: austria,
    slovenia: slovenia
  });
}.run().value;

console.log(colorSet);

Transform

to have the javascript code apply the provided macro.

node_modules/.bin/sjs --module ambjs/macro <file>