operator-dot.go: the '.' (dot) operator can now only be used to call member functions of iterators

operator-dot.go

@@ -4,8 +4,6 @@
 // operator-dot.go
 package expr
 
-import "fmt"
-
 // -------- dot term
 func newDotTerm(tk *Token) (inst *term) {
 	return &term{
@@ -17,24 +15,6 @@ func newDotTerm(tk *Token) (inst *term) {
 	}
 }
 
-func verifyDotIndex(ctx ExprContext, indexTerm *term, maxValue int) (index int, err error) {
-	var v int
-	var indexValue any
-	if indexValue, err = indexTerm.compute(ctx); err == nil {
-		if v, err = indexTerm.toInt(indexValue, "index expression value must be integer"); err == nil {
-			if v < 0 && v >= -maxValue {
-				v = maxValue + v
-			}
-			if v >= 0 && v < maxValue {
-				index = v
-			} else {
-				err = indexTerm.Errorf("index %d out of bounds", v)
-			}
-		}
-	}
-	return
-}
-
 func evalDot(ctx ExprContext, self *term) (v any, err error) {
 	var leftValue, rightValue any
 
@@ -48,27 +28,8 @@ func evalDot(ctx ExprContext, self *term) (v any, err error) {
 	indexTerm := self.children[1]
 
 	switch unboxedValue := leftValue.(type) {
-	case *ListType:
-		var index int
-		array := ([]any)(*unboxedValue)
-		if index, err = verifyDotIndex(ctx, indexTerm, len(array)); err == nil {
-			v = array[index]
-		}
-	case string:
-		var index int
-		if index, err = verifyDotIndex(ctx, indexTerm, len(unboxedValue)); err == nil {
-			v = string(unboxedValue[index])
-		}
-	case *DictType:
-		var ok bool
-		var indexValue any
-		if indexValue, err = indexTerm.compute(ctx); err == nil {
-			if v, ok = (*unboxedValue)[indexValue]; !ok {
-				err = fmt.Errorf("key %v does not belong to the dictionary", rightValue)
-			}
-		}
 	case ExtIterator:
-		if indexTerm.symbol() == SymVariable {
+		if indexTerm.symbol() == SymVariable /*|| indexTerm.symbol() == SymString */ {
 			opName := indexTerm.source()
 			if unboxedValue.HasOperation(opName) {
 				v, err = unboxedValue.CallOperation(opName, []any{})
@@ -76,10 +37,14 @@ func evalDot(ctx ExprContext, self *term) (v any, err error) {
 				err = indexTerm.Errorf("this iterator do not support the %q command", opName)
 				v = false
 			}
+		} else {
+			err = indexTerm.tk.ErrorExpectedGot("identifier")
 		}
 	default:
+		if rightValue, err = self.children[1].compute(ctx); err == nil {
 			err = self.errIncompatibleTypes(leftValue, rightValue)
 		}
+	}
 	return
 }