How can I simulate macros in JavaScript?

Question

I know that JavaScript doesn\'t support macros (Lisp-style ones) but I was wondering if anyone had a solution to maybe simulate macros? I Googled it, and one of the solution

Answer 1

function unless(condition,body) {
    return 'if(! '+condition.toSource()+'() ) {' + body.toSource()+'(); }';
}


eval(unless( function() {
    return false;
  }, function() {
    alert("OK");
}));

Answer 2

A library by Mozilla (called SweetJS) is designed to simulate macros in JavaScript. For example, you can use SweetJS to replace the function keyword with def.

Answer 3

LispyScript is the latest language that compiles to Javascript, that supports macros. It has a Lisp like tree syntax, but also maintains the same Javascript semantics. Disclaimer: I am the author of LispyScript.

Answer 4

You could use parenscript. That'll give you macros for Javascript.

Answer 5

Check out the Linux/Unix/GNU M4 processor. It is a generic and powerful macro processor for any language. It is especially oriented towards Algol-style languages of which JavaScript is a member.

Answer 6

Javascript is interpreted. Eval isn't any more costly that anything else in Javascript.