Silly experiments with "macros" in JS.

ghettomacro.js

function macro(mfun) {
    var fstr   = mfun.toString(),
        params = fstr
                  .match(/^function\s*\((.*)\)/)[1]
                  .replace(/\s+/,'').split(','),
        msrc   = fstr.match(/^function\s*\(.*\)\s*\{((?:.|\n)*)\}\s*$/)[1];
    
    console.log(fstr, params, msrc);
    
    return function() {
        var src = msrc;
        for(var i = 0; i < params.length; i++) 
            src = src.replace(params[i], arguments[i]);
            
        return new Function(src);   
    };
}

var calc = macro(function(formula){
    var x = 1;
    for(var i = 0; i < 10; i++) {
        x = formula;
        console.log("X = ", x, "formula");
    }
});

calc("i * 2")();
calc("x + i/2")();