Add index to map iteration

for_tag.go

@@ -1,6 +1,7 @@
 package salix
 
 import (
+	"errors"
 	"reflect"
 
 	"go.elara.ws/salix/ast"
@@ -10,34 +11,26 @@ import (
 type forTag struct{}
 
 func (ft forTag) Run(tc *TagContext, block, args []ast.Node) error {
-	if len(args) == 0 || len(args) > 2 {
+	if len(args) == 0 || len(args) > 3 {
 		return tc.PosError(tc.Tag, "invalid argument amount")
 	}
 
-	var expr ast.Expr
-	if len(args) == 1 {
-		expr2, ok := args[0].(ast.Expr)
-		if !ok {
-			return tc.PosError(args[0], "invalid argument type: %T (expected ast.Expr)", args[0])
-		}
-		expr = expr2
-	} else if len(args) == 2 {
-		expr2, ok := args[1].(ast.Expr)
-		if !ok {
-			return tc.PosError(args[1], "invalid argument type: %T (expected ast.Expr)", args[1])
-		}
-		expr = expr2
+	expr, ok := args[len(args)-1].(ast.Expr)
+	if !ok {
+		return tc.PosError(args[0], "invalid argument type: %T (expected ast.Expr)", args[0])
 	}
 
 	var vars []string
 	var in reflect.Value
 
-	if len(args) == 2 {
-		varName, ok := unwrap(args[0]).(ast.Ident)
-		if !ok {
-			return tc.PosError(args[0], "invalid argument type: %T (expected ast.Ident)", expr.First)
+	if len(args) > 1 {
+		for _, arg := range args[:len(args)-1] {
+			varName, ok := unwrap(arg).(ast.Ident)
+			if !ok {
+				return tc.PosError(arg, "invalid argument type: %T (expected ast.Ident)", expr.First)
+			}
+			vars = append(vars, varName.Value)
 		}
-		vars = append(vars, varName.Value)
 	}
 
 	varName, ok := unwrap(expr.First).(ast.Ident)
@@ -70,6 +63,8 @@ func (ft forTag) Run(tc *TagContext, block, args []ast.Node) error {
 			} else if len(vars) == 2 {
 				local[vars[0]] = i
 				local[vars[1]] = in.Index(i).Interface()
+			} else {
+				return errors.New("slices and arrays can only use two for loop variables")
 			}
 
 			err = tc.Execute(block, local)
@@ -80,18 +75,25 @@ func (ft forTag) Run(tc *TagContext, block, args []ast.Node) error {
 	case reflect.Map:
 		local := map[string]any{}
 		iter := in.MapRange()
+		i := 0
 		for iter.Next() {
 			if len(vars) == 1 {
 				local[vars[0]] = iter.Value().Interface()
 			} else if len(vars) == 2 {
 				local[vars[0]] = iter.Key().Interface()
 				local[vars[1]] = iter.Value().Interface()
+			} else if len(vars) == 3 {
+				local[vars[0]] = i
+				local[vars[1]] = iter.Key().Interface()
+				local[vars[2]] = iter.Value().Interface()
 			}
 
 			err = tc.Execute(block, local)
 			if err != nil {
 				return err
 			}
+
+			i++
 		}
 	}