leftToRight = false; prefix = "ltr"; postfix = "rtl";

tokens = { “=” : [7], “==” : [6], “+” : [5], “-” : [5], “*” : [4], “/” : [4], “!” : [1, prefix], “~” : [1, prefix], “^” : [1], " " : [-1], “(” : [0, next], “)” : [0, “<”] };

for(var i = 0; i < 10; i += 1) tokens[i] = [0];

// each token is defined such [priority, param] // if param is a function it will be used to enter a scope // if param is “<” it will end a scope // if param is “ltr”/“rtl” the token will be processed as such

// this function gets our next token from input // this returns // name : name of the token // ltr : should this token be in left to right order // priority : priority of the token // scope : which scope should this token enter // exit : should this token end current scope

function next(root, input){ var token = input.shift(), action = tokens[token]; if(typeof action === “undefined” ){ return { name : token, ltr : leftToRight, priority : 0, }; }

var priority, param;

if( action instanceof Array ){
    priority = parseFloat(action[0]);
    param = action[1];
} else {
    priority = parseFloat(action);
    param = undefined;
}

if(typeof param === "function"){
    return {
        name : token,
        ltr : leftToRight,
        priority : priority,
        scope : param
    };
} else if (param === "<"){
    return {
        name : token,
        ltr : leftToRight,
        priority : priority,
        exit : true
    };
}

var ltr = leftToRight;
if(param === "ltr"){
    ltr = true;
} else if (param === "rtl") {
    ltr = false;
}

return {
    name : token,
    priority : priority,
    ltr : ltr
};

}

// the last row should say what is // the first scope parser next;