function definition and usage rationalized

operand-func.go

@@ -76,30 +76,30 @@ func newFuncDefTerm(tk *Token, args []*term) *term {
 
 // -------- eval func def
 // TODO
-type funcDefFunctor struct {
-	params []string
-	expr   Expr
-}
+// type funcDefFunctor struct {
+// 	params []string
+// 	expr   Expr
+// }
 
-func (funcDef *funcDefFunctor) Invoke(ctx ExprContext, name string, args []any) (result any, err error) {
-	for i, p := range funcDef.params {
-		if i < len(args) {
-			arg := args[i]
-			if functor, ok := arg.(Functor); ok {
-				// ctx.RegisterFunc(p, functor, 0, -1)
-				ctx.RegisterFunc2(p, functor, typeAny, []ExprFuncParam{
-					newFuncParam(paramValue),
-				})
-			} else {
-				ctx.UnsafeSetVar(p, arg)
-			}
-		} else {
-			ctx.UnsafeSetVar(p, nil)
-		}
-	}
-	result, err = funcDef.expr.eval(ctx, false)
-	return
-}
+// func (funcDef *funcDefFunctor) Invoke(ctx ExprContext, name string, args []any) (result any, err error) {
+// 	for i, p := range funcDef.params {
+// 		if i < len(args) {
+// 			arg := args[i]
+// 			if functor, ok := arg.(Functor); ok {
+// 				// ctx.RegisterFunc(p, functor, 0, -1)
+// 				ctx.RegisterFunc2(p, functor, typeAny, []ExprFuncParam{
+// 					newFuncParam(paramValue),
+// 				})
+// 			} else {
+// 				ctx.UnsafeSetVar(p, arg)
+// 			}
+// 		} else {
+// 			ctx.UnsafeSetVar(p, nil)
+// 		}
+// 	}
+// 	result, err = funcDef.expr.eval(ctx, false)
+// 	return
+// }
 
 func evalFuncDef(ctx ExprContext, self *term) (v any, err error) {
 	bodySpec := self.value()
@@ -108,10 +108,11 @@ func evalFuncDef(ctx ExprContext, self *term) (v any, err error) {
 		for _, param := range self.children {
 			paramList = append(paramList, param.source())
 		}
-		v = &funcDefFunctor{
-			params: paramList,
-			expr:   expr,
-		}
+		v = newExprFunctor(expr, paramList)
+		// v = &funcDefFunctor{
+		// 	params: paramList,
+		// 	expr:   expr,
+		// }
 	} else {
 		err = errors.New("invalid function definition: the body specification must be an expression")
 	}