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tangentstorm/something4thy.js

Created August 2, 2013 04:22
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  1. tangentstorm created this gist Aug 2, 2013.
    68 changes: 68 additions & 0 deletions something4thy.js
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,68 @@
    var b4 = (new function() { var EOF='\0',self = {

    d:[], a:[], // data and auxiliary/return stack
    defs:[],core:[],scope:[], // dictionary
    base:10, // numbers
    cp:-1, ch:'\x01',ibuf:[],wd:'', // lexer state
    compiling:false,state:[],target:[], // compiler state

    def : function (k,v){
    var res=self.defs.length; self.defs.push(v); self.scope[0].push([k,res]); return res },

    tos : function(){return d.length ? d[d.length-1]:null},

    nextch : function(){
    this.cp++;
    while (this.ibuf.length && (this.cp>=this.ibuf[0].length)) {this.cp=0; this.ibuf.shift();}
    this.ch = (this.ibuf.length ? this.ibuf[0][this.cp] : EOF);
    return this.ch },

    word : function(){
    var res=[];
    while (this.ch <= ' ') if (this.ch===EOF) { return false } else this.nextch();
    while (this.ch > ' ') { res.push(this.ch); this.nextch() }
    this.wd = res.join('');
    return true },

    send : function(s){ self.ibuf.push(s) },

    findwd : function() {
    var found = false;
    for (var i=self.scope.length-1; i>=0 && !found; i--){
    for (var dict=self.scope[i], j=dict.length-1; j>=0 && !found; j--) {
    if (dict[j][0]===this.wd) { found=true; self.d.push(dict[j][1]) }}}
    return found },

    lift : function(n) { return function(){ self.d.push(n) }},

    number : function() {
    var i = parseInt(this.wd,this.base);
    if (isNaN(i)) {return false} else {self.d.push(i); return true }},

    error : function(msg){ console.log('error:',msg); throw msg },

    run : function(s){
    var op;
    this.send(s);
    while (this.word()) {
    op = this.findwd() ? this.defs[self.d.pop()]
    : this.number() ? this.lift(self.d.pop())
    : function() { self.error(self.wd+'?') };
    if (this.compiling) { self.target.push(op) } else op.call(self);
    console.log('wd: ', self.wd, '->', self.d); }
    return this;}
    };// end self

    var coreOps=[
    ['+', function (){self.d.push(self.d.pop()+self.d.pop())}],
    ['-', function(){self.d.push(self.d.pop()-self.d.pop())}],
    ['*', function (){self.d.push(self.d.pop()*self.d.pop())}],
    ['base', function(){self.d.push(self.base)}],
    ['compiling?', function(){self.d.push(self.compiling.length)}]];

    self.scope.push(self.core);
    for (var i=0; i<coreOps.length;++i) self.def.apply(self, coreOps[i]);
    return self;
    });
    b4.run('1 2 + 3 *');
    console.log(b4.d.pop());