Basic experiment to add named arguments / parameters to Haxe. Using Haxe r6642

Macro.hx

package example.namedArgs;

import haxe.macro.Type;
import haxe.macro.Expr;
import haxe.macro.Context;

using StringTools;
using uhu.macro.Jumla;

/**
 * ...
 * @author Skial Bainn
 */
class Macro {

    public static function build() {
		var cls = Context.getLocalClass().get();
		var fields = Context.getBuildFields();
		
		for (field in fields) {
			
			switch (field.kind) {
				
				case FFun(method):
					
					method.expr = loop( method.expr );
					
				case _:
				
			}
			
		}
		
		return fields;
	}
	
	public static function loop(e:Expr):Expr {
		var result = e;
		
		switch (e.expr) {
			case EBlock(exprs):
				
				result = { expr:EBlock( [for (expr in exprs) loop( expr )] ), pos: e.pos };
				
			case ECall(expr, params):
				
				var copy = params.copy();
				
				var matches:Array<{e:Expr, n:String, pos:Int}> = [];
				
				for (i in 0...params.length) {
					
					var val:Expr = params[i];
					
					if (val.expr.getName() == 'EMeta') {
						
						var type = expr.printExpr().find();
						var arity = type.arity();
						var args = type.args();
						
						var meta:MetadataEntry = val.expr.getParameters()[0];
						var name:String = meta.name.replace(':', '');
						
						matches.push( { e: val, n: name , pos: args.indexOf( name ) } );
						
						copy = copy.splice(0, i).concat( copy.splice(i + 1, -1) );
						
					}
					
				}
				
				for (match in matches) {
					
					if (match.pos == -1) {
						trace( match );
					}
					
					while (match.pos > copy.length - 1) {
						
						copy.push(macro null);
						
					}
					
					copy[match.pos] = match.e.expr.getParameters()[1];
					
				}
				
				result = { expr: ECall( expr, copy ), pos: e.pos };
				
			case _:
				trace( e );
		}
		
		return result;
	}
	
}

Main.hx

package example.namedArgs;

/**
 * ...
 * @author Skial Bainn
 */
@:build( example.namedArgs.Macro.build() )
class Main {

    public static function main() {
		foo( true, false, true, @:g false );
	}
	
	public static function foo(a:Bool, b:Bool, c:Bool, d:Bool = false, e:Bool = true, f:Bool = false, g:Bool = true) {
		trace('a = $a');
		trace('b = $b');
		trace('c = $c');
		trace('d = $d');
		trace('e = $e');
		trace('f = $f');
		trace('g = $g');
	}
	
}

output.js

(function () { "use strict";
var Std = function() { }
Std.__name__ = true;
Std.string = function(s) {
    return js.Boot.__string_rec(s,"");
}
var example = {}
example.namedArgs = {}
example.namedArgs.Main = function() { }
example.namedArgs.Main.__name__ = true;
example.namedArgs.Main.main = function() {
	example.namedArgs.Main.foo(true,false,true,null,null,null,false);
}
example.namedArgs.Main.foo = function(a,b,c,d,e,f,g) {
	if(g == null) g = true;
	if(f == null) f = false;
	if(e == null) e = true;
	if(d == null) d = false;
	console.log("a = " + Std.string(a));
	console.log("b = " + Std.string(b));
	console.log("c = " + Std.string(c));
	console.log("d = " + Std.string(d));
	console.log("e = " + Std.string(e));
	console.log("f = " + Std.string(f));
	console.log("g = " + Std.string(g));
}
var js = {}
js.Boot = function() { }
js.Boot.__name__ = true;
js.Boot.__string_rec = function(o,s) {
	if(o == null) return "null";
	if(s.length >= 5) return "<...>";
	var t = typeof(o);
	if(t == "function" && (o.__name__ || o.__ename__)) t = "object";
	switch(t) {
	case "object":
		if(o instanceof Array) {
			if(o.__enum__) {
				if(o.length == 2) return o[0];
				var str = o[0] + "(";
				s += "\t";
				var _g1 = 2, _g = o.length;
				while(_g1 < _g) {
					var i = _g1++;
					if(i != 2) str += "," + js.Boot.__string_rec(o[i],s); else str += js.Boot.__string_rec(o[i],s);
				}
				return str + ")";
			}
			var l = o.length;
			var i;
			var str = "[";
			s += "\t";
			var _g = 0;
			while(_g < l) {
				var i1 = _g++;
				str += (i1 > 0?",":"") + js.Boot.__string_rec(o[i1],s);
			}
			str += "]";
			return str;
		}
		var tostr;
		try {
			tostr = o.toString;
		} catch( e ) {
			return "???";
		}
		if(tostr != null && tostr != Object.toString) {
			var s2 = o.toString();
			if(s2 != "[object Object]") return s2;
		}
		var k = null;
		var str = "{\n";
		s += "\t";
		var hasp = o.hasOwnProperty != null;
		for( var k in o ) { ;
		if(hasp && !o.hasOwnProperty(k)) {
			continue;
		}
		if(k == "prototype" || k == "__class__" || k == "__super__" || k == "__interfaces__" || k == "__properties__") {
			continue;
		}
		if(str.length != 2) str += ", \n";
		str += s + k + " : " + js.Boot.__string_rec(o[k],s);
		}
		s = s.substring(1);
		str += "\n" + s + "}";
		return str;
	case "function":
		return "<function>";
	case "string":
		return o;
	default:
		return String(o);
	}
}
String.__name__ = true;
Array.__name__ = true;
example.namedArgs.Main.main();
})();