Haxe build macro sample: adding method

MyMacro.hx

#if macro
import haxe.macro.Context;
import haxe.macro.Expr;
import haxe.macro.TypeTools;

class MethodBuilder {
	public static function build(): Array<Field> {
		final fields = Context.getBuildFields();

		final localType = Context.getLocalType();
		if (localType == null) throw "Oh no";

		final thisType = TypeTools.toComplexType(localType);

		final parameterType = switch localType {
      case TInst(_, [p]):
        TypeTools.toComplexType(p);
      default: return null;
    }

		final pos = Context.currentPos();

		final myFunction: Function = {
			expr: macro {
				$i{"this"}.myVar = myArg;
				return $i{"this"};
			},
			ret: (macro:$thisType),
			args: [{ name: "myArg", type: (macro:Int)}]
		};

		final setMethod: Field = {
			name: "myFunc",
			access: [
				Access.APublic,
				Access.AInline
			],
			kind: FieldType.FFun(myFunction),
			pos: pos,
		};

		fields.push(setMethod);

		return fields;
	}
}
#end