Created
August 2, 2013 04:22
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something 4thy this way comes...
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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()); |
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