Лексический анализатор

function lexer(config){

var stack=[""];

var data=(function(config){

var data={};

for(var state in config){

data[state]=(function(src){

for(var a=[],i=0;i<src.length;i++){

var re=src[i][0];

var fn=src[i][1];

if(re instanceof RegExp)

re=new RegExp("^("+re.source+").*",'m');

else re=new RegExp("^("+re+").*",'m');

if(!(fn instanceof Function))

fn=new Function("",fn);

a.push([re,fn]);

}

return a;})(config[state]);

}
return data;})(config);

var control={

begin:function(state){

if(state in config)

stack[0]=state;

else throw "wrong state";

},

push:function(){

if(state in config)

stack.unshift(state);

else throw "wrong state";

},

pop:function(){return stack.shift();},

top:function(){return stack[0];},

}

function lex(text){

while(text.length>0){

var token=step.apply(this,[text]);

puts(token);

if(token)

text=text.substring(token.length);

}

}

function step(text){

var current=data[stack[0]];

var token;

for(var ci in current)if(token=(function(re,fn){

var match=re(text);

var token=match&&match[1];

if(token){

control.text=token;

fn.apply(this,[control]);

return token;

}

})(current[ci][0],current[ci][1]))return token;

throw "not found";

}

return lex;}