js let macro

letmacro.js

macro $let {
	case ( $($id:ident = $val:expr) (,) ... ) $body => { 
		/*(function(){		
			$(var $id = $val;) ...
			var ____r = (function() $body)();
			return ____r;
		})()*/
		(function ($id (,) ...) $body)($val (,) ...)
	}	
}

var v = $let(a='hello',b='world') {
	return a + b;
};

console.log(v);