RL Interpreter in JavaScript...Because FUN

rl.js

(function(root, factory) {
  if (typeof define === 'function') {
    define(factory);
  } else if (typeof exports === 'object') {
    module.exports = factory();
  } else {
    root.RL = factory();
  }
})(this, function() {
  var run = function(code, stack, dict) {
    var word, words, stack = stack || [], dict = dict || {};

    if (code instanceof Array) {
      words = code;
    } else {
      var words = code.split(/\s+/g).map(function(word, n) {
        if (isNaN(n = parseFloat(word))) {
          return word.toLowerCase();
        } else {
          return n;
        }
      }).reverse();
    }

    while (words.length) {
      word = words.pop();

      if (typeof word === 'number') {
        stack.push(word);
      } else {
        var entry;

        if (library[word]) {
          entry = library[word];
        } else if (dict[word]) {
          entry = dict[word];
        } else {
          entry = null;
        }

        if (typeof entry === 'function') {
          entry(stack, words, dict);
        } else {
          stack.push(entry);
        }
      }
    }

    return stack;
  };

  var library = {
    ':': function(stack, words, dict) {
      var word, block = [];

      while ((word = words.pop()) !== ';') {
        block.push(word);
      }

      dict[block.shift()] = function(stack, words, dict) {
        run(block.slice(0), stack, dict);
      };
    },

    dup: function(stack) {
      var x = stack.pop();

      stack.push(x);
      stack.push(x);
    },

    over: function(stack) {
      var first = stack.pop(), second = stack.pop();

      stack.push(first);
      stack.push(second);
      stack.push(first);
    },

    '2dup': function(stack) {
      var first = stack.pop(), second = stack.pop();

      stack.push(second);
      stack.push(first);
      stack.push(second);
      stack.push(first);
    },

    rot: function(stack) {
      var first = stack.pop(), second = stack.pop(), third = stack.pop();

      stack.push(first);
      stack.push(third);
      stack.push(second);
    },

    '-rot': function(stack) {
      var first = stack.pop(), second = stack.pop(), third = stack.pop();

      stack.push(second);
      stack.push(first);
      stack.push(third);
    },

    '=': function(stack) {
      var y = stack.pop(), x = stack.pop();

      stack.push(x === y);
    },

    '<': function(stack) {
      var y = stack.pop(), x = stack.pop();

      stack.push(+(x < y));
    },

    '>': function(stack) {
      var y = stack.pop(), x = stack.pop();

      stack.push(+(x > y));
    },

    '<=': function(stack) {
      var y = stack.pop(), x = stack.pop();

      stack.push(+(x <= y));
    },

    '>=': function(stack) {
      var y = stack.pop(), x = stack.pop();

      stack.push(+(x >= y));
    },

    and: function(stack) {
      var y = stack.pop(), x = stack.pop();

      stack.push(+(x && y));
    },

    or: function(stack) {
      var y = stack.pop(), x = stack.pop();

      stack.push(+(x || y));
    },

    not: function(stack) {
      stack.push(+!stack.pop());
    },

    min: function(stack) {
      var y = stack.pop(), x = stack.pop();

      stack.push(Math.min(x, y));
    },

    max: function(stack) {
      var y = stack.pop(), x = stack.pop();

      stack.push(Math.max(x, y));
    },

    '+': function(stack) {
      var y = stack.pop(), x = stack.pop();

      stack.push(x + y);
    },

    '-': function(stack) {
      var y = stack.pop(), x = stack.pop();

      stack.push(x - y);
    },

    '*': function(stack) {
      var y = stack.pop(), x = stack.pop();

      stack.push(x * y);
    },

    '/': function(stack) {
      var y = stack.pop(), x = stack.pop();

      stack.push(x / y);
    },

    mod: function(stack) {
      var y = stack.pop(), x = stack.pop();

      stack.push(x % y);
    },

    pow: function(stack) {
      var y = stack.pop(), x = stack.pop();

      stack.push(Math.pow(x, y));
    },

    atan: function(stack) {
      stack.push(Math.atan(stack.pop()));
    },

    negate: function(stack) {
      stack.push(Math.negate(stack.pop()));
    },

    sin: function(stack) {
      stack.push(Math.sin(stack.pop()));
    },

    cos: function(stack) {
      stack.push(Math.cos(stack.pop()));
    },

    tan: function(stack) {
      stack.push(Math.tan(stack.pop()));
    },

    log: function(stack) {
      stack.push(Math.log(stack.pop()));
    },

    exp: function(stack) {
      stack.push(Math.exp(stack.pop()));
    },

    sqrt: function(stack) {
      stack.push(Math.sqrt(stack.pop()));
    },

    floor: function(stack) {
      stack.push(Math.floor(stack.pop()));
    },

    ceil: function(stack) {
      stack.push(Math.ceil(stack.pop()));
    },

    abs: function(stack) {
      stack.push(Math.abs(stack.pop()));
    },

    pi: Math.PI,

    random: function(stack) {
      stack.push(Math.random());
    }
  };

  return run;
});