helper for clean expression building

src/kiss/Helpers.hx

@@ -328,4 +328,20 @@ class Helpers {
         };
         return def.withPosOf(exp);
     }
+
+    // Return convenient functions for succinctly making new ReaderExps that link back to an original exp's
+    // position in source code
+    public static function expBuilder(posRef:ReaderExp) {
+        return {
+            call: (func:ReaderExp, args:Array<ReaderExp>) -> CallExp(func, args).withPosOf(posRef),
+            list: (exps:Array<ReaderExp>) -> ListExp(exps).withPosOf(posRef),
+            str: (s:String) -> StrExp(s).withPosOf(posRef),
+            symbol: (name:String) -> Symbol(name).withPosOf(posRef),
+            raw: (code:String) -> RawHaxe(code).withPosOf(posRef),
+            typed: (path:String, exp:ReaderExp) -> TypedExp(path, exp).withPosOf(posRef),
+            meta: (m:String, exp:ReaderExp) -> MetaExp(m, exp).withPosOf(posRef),
+            field: (f:String, exp:ReaderExp) -> FieldExp(f, exp).withPosOf(posRef),
+            keyValue: (key:ReaderExp, value:ReaderExp) -> KeyValueExp(key, value).withPosOf(posRef),
+        };
+    }
 }

src/kiss/Macros.hx

@@ -22,7 +22,14 @@ class Macros {
         function destructiveVersion(op:String, assignOp:String) {
             macros[assignOp] = (wholeExp:ReaderExp, exps:Array<ReaderExp>, k) -> {
                 wholeExp.checkNumArgs(2, null, '($assignOp [var] [v1] [values...])');
-                CallExp(Symbol("set").withPosOf(wholeExp), [exps[0], CallExp(Symbol(op).withPosOf(wholeExp), exps).withPosOf(wholeExp)]).withPosOf(wholeExp);
+                var b = wholeExp.expBuilder();
+                b.call(
+                    b.symbol("set"), [
+                        exps[0],
+                        b.call(
+                            b.symbol(op),
+                            exps)
+                    ]);
             };
         }