Main.hx

 class Main
{
	public function new()
	{
		trace("hello");
		var g=new SubOB();
		trace(g.pull);
		g.pull="over";
		trace(g.pull);
	}
	
	static public function main()
  	{
		var app = new Main();
	}
}

OBMacros.hx

import haxe.macro.Context;
import haxe.macro.Expr;
class OBMacros{


	public static function macroBuild() {
		trace( "macrobuild");
		
		var fields = Context.getBuildFields();
		var hasManager = false;
		for( f in fields ) {
			
			
			for( m in f.meta )
				switch( m.name ) {
				case ":postite":
					
					trace( "postite meta found");
					switch( f.kind ) {
				 	case FVar(t, _):
				 		trace( "FVar"+t);
				 		
				 		var pos = f.pos;
						var ttype = t, tname;
						trace(pos );
						trace( ttype);
							 
								function e(expr) return { expr : expr, pos : pos };

								// i substr( "_") because i don't know how to delete the field or replace it 
								//generate getter
						 		var get = {
						 			args : [],
						 			params : [],
						 			ret : t,
						 			expr : Context.parse("return untyped  "+f.name.substr(1),pos),
						 		};
						 		

						 		// tried @:noCompletion for fun
						 		var meta = [{ name : ":noCompletion", params : [], pos : pos }];
						 		fields.push({ name : "get_"+f.name.substr(1), pos : pos, meta :meta , access : [APrivate], doc : null, kind : FFun(get) });
						 		//generate setter

						 		var set = {
								args : [{ name : "_v", opt : false, type : t, value : null }],
								params : [],
								ret : t,
								expr : Context.parse("return this."+f.name.substr(1)+"=_v",pos),
								};
						 		//var meta = [{ name : ":hide", params : [], pos : pos }];
						 		var meta = [{ name : ":hide", params : [], pos : pos }];
						 		fields.push({ name : "set_"+f.name.substr(1), pos : pos, meta :meta , access : [APrivate], doc : null, kind : FFun(set) });

						 		//generate (get,set) field
						 		var meta = [{ name : ":isVar", params : [], pos : pos }];
						 		var newField = {
        					    name: f.name.substr(1),
        					    doc: null,
        					    meta: meta,
        					    access: [APublic],
        					    kind: FProp("get","set",macro "polo"), // cannot get the value from _pull eg :'marin'
        					    pos: Context.currentPos()
        					};

        					fields.push(newField);
		
				 	case _:
				 	trace( "not a var");
				 	}
				
				default:
				trace( "default");
				}
			
			switch( f.kind ) {
			case FVar(t, _):
			trace("kind="+ t);
				// if( t != null )
				// 	buildField(f,fields,t,t);
			default:
			}
		}
		 
        
        
		
		return fields;
	}
}

SubOB.hx

class SubOB extends OB{

	@:postite
	var _pull:String="marin";


	 public function new():Void
	{
		trace( "new sub");
	}
}