Fix for loop parsing and add @if/@for in attribute positions

grammar.js

@@ -9,7 +9,6 @@ module.exports = grammar({
   conflicts: ($) => [
     [$.expression, $.pattern],
     [$.rust_path, $.expression],
-    [$.struct_pattern, $.expression],
     [$.html_element],
     [$.self_closing_function_tag, $.container_function_tag],
   ],
@@ -120,12 +119,14 @@ module.exports = grammar({
     content_block: ($) => seq("{", repeat($.template_node), "}"),
 
     // Template nodes
+    // Note: template_control_flow must come before template_expression
+    // to avoid @for/@if/@let being parsed as variable expressions
     template_node: ($) =>
       choice(
         $.html_element,
         $.function_tag,
-        $.template_expression,
         $.template_control_flow,
+        $.template_expression,
         $.comment,
         $.embedded_language,
         $.escape_at,
@@ -133,17 +134,18 @@ module.exports = grammar({
       ),
 
     // HTML elements
+    // Note: attribute_or_control allows @if/@for in attribute position
     html_element: ($) =>
       choice(
         // Self-closing tag
-        seq("<", $.tag_name, repeat($.html_attribute), "/", ">"),
+        seq("<", $.tag_name, repeat($.attribute_or_control), "/", ">"),
         // Void elements (no closing tag needed)
-        seq("<", $.tag_name, repeat($.html_attribute), ">"),
+        seq("<", $.tag_name, repeat($.attribute_or_control), ">"),
         // Full element with content and closing tag
         seq(
           "<",
           $.tag_name,
-          repeat($.html_attribute),
+          repeat($.attribute_or_control),
           ">",
           repeat($.template_node),
           "</",
@@ -152,11 +154,47 @@ module.exports = grammar({
         ),
       ),
 
+    // Allow either HTML attributes or control flow (@if/@for) in attribute position
+    attribute_or_control: ($) =>
+      choice(
+        $.html_attribute,
+        $.attribute_control_flow,
+      ),
+
+    // Control flow in attribute context - produces attributes conditionally
+    attribute_control_flow: ($) =>
+      choice(
+        $.attribute_if_statement,
+        $.attribute_for_loop,
+      ),
+
+    attribute_if_statement: ($) =>
+      seq(
+        "@if",
+        $.expression,
+        "{",
+        repeat($.attribute_or_control),
+        "}",
+        optional(seq("else", "{", repeat($.attribute_or_control), "}")),
+      ),
+
+    attribute_for_loop: ($) =>
+      seq(
+        "@for",
+        $.simple_pattern,
+        "in",
+        $.expression,
+        "{",
+        repeat($.attribute_or_control),
+        "}",
+      ),
+
     tag_name: ($) => /[a-zA-Z][a-zA-Z0-9-]*/,
 
     html_attribute: ($) =>
       seq($.attribute_name, optional(seq("=", $.attribute_value))),
 
+    // Attribute names: allow @ for directives like @click, but not @if/@for/@let
     attribute_name: ($) => /[a-zA-Z_:@][a-zA-Z0-9_:.-]*/,
 
     attribute_value: ($) =>
@@ -236,7 +274,7 @@ module.exports = grammar({
       seq(
         "@for",
         optional(seq($.identifier, ":")),
-        $.pattern,
+        $.simple_pattern,
         "in",
         $.expression,
         $.content_block,
@@ -312,14 +350,23 @@ module.exports = grammar({
 
     unquoted_value: ($) => /[^\s>=\/]+/,
 
-    // Patterns
+    // Patterns - full patterns used in match arms
     pattern: ($) =>
       choice(
         $.wildcard_pattern,
         $.tuple_pattern,
         $.struct_pattern,
-        $.identifier_pattern,
         $.literal,
+        $.identifier_pattern,
+      ),
+
+    // Simple pattern for for loops - no struct patterns to avoid ambiguity with content_block
+    simple_pattern: ($) =>
+      choice(
+        $.wildcard_pattern,
+        $.tuple_pattern,
+        $.literal,
+        $.identifier_pattern,
       ),
 
     wildcard_pattern: ($) => "_",

src/grammar.json

@@ -607,11 +607,11 @@
         },
         {
           "type": "SYMBOL",
-          "name": "template_expression"
+          "name": "template_control_flow"
         },
         {
           "type": "SYMBOL",
-          "name": "template_control_flow"
+          "name": "template_expression"
         },
         {
           "type": "SYMBOL",
@@ -649,7 +649,7 @@
               "type": "REPEAT",
               "content": {
                 "type": "SYMBOL",
-                "name": "html_attribute"
+                "name": "attribute_or_control"
               }
             },
             {
@@ -677,7 +677,7 @@
               "type": "REPEAT",
               "content": {
                 "type": "SYMBOL",
-                "name": "html_attribute"
+                "name": "attribute_or_control"
               }
             },
             {
@@ -701,7 +701,7 @@
               "type": "REPEAT",
               "content": {
                 "type": "SYMBOL",
-                "name": "html_attribute"
+                "name": "attribute_or_control"
               }
             },
             {
@@ -731,6 +731,128 @@
         }
       ]
     },
+    "attribute_or_control": {
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "SYMBOL",
+          "name": "html_attribute"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "attribute_control_flow"
+        }
+      ]
+    },
+    "attribute_control_flow": {
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "SYMBOL",
+          "name": "attribute_if_statement"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "attribute_for_loop"
+        }
+      ]
+    },
+    "attribute_if_statement": {
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "@if"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "expression"
+        },
+        {
+          "type": "STRING",
+          "value": "{"
+        },
+        {
+          "type": "REPEAT",
+          "content": {
+            "type": "SYMBOL",
+            "name": "attribute_or_control"
+          }
+        },
+        {
+          "type": "STRING",
+          "value": "}"
+        },
+        {
+          "type": "CHOICE",
+          "members": [
+            {
+              "type": "SEQ",
+              "members": [
+                {
+                  "type": "STRING",
+                  "value": "else"
+                },
+                {
+                  "type": "STRING",
+                  "value": "{"
+                },
+                {
+                  "type": "REPEAT",
+                  "content": {
+                    "type": "SYMBOL",
+                    "name": "attribute_or_control"
+                  }
+                },
+                {
+                  "type": "STRING",
+                  "value": "}"
+                }
+              ]
+            },
+            {
+              "type": "BLANK"
+            }
+          ]
+        }
+      ]
+    },
+    "attribute_for_loop": {
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "@for"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "simple_pattern"
+        },
+        {
+          "type": "STRING",
+          "value": "in"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "expression"
+        },
+        {
+          "type": "STRING",
+          "value": "{"
+        },
+        {
+          "type": "REPEAT",
+          "content": {
+            "type": "SYMBOL",
+            "name": "attribute_or_control"
+          }
+        },
+        {
+          "type": "STRING",
+          "value": "}"
+        }
+      ]
+    },
     "tag_name": {
       "type": "PATTERN",
       "value": "[a-zA-Z][a-zA-Z0-9-]*"
@@ -1172,7 +1294,7 @@
         },
         {
           "type": "SYMBOL",
-          "name": "pattern"
+          "name": "simple_pattern"
         },
         {
           "type": "STRING",
@@ -1578,13 +1700,34 @@
           "type": "SYMBOL",
           "name": "struct_pattern"
         },
+        {
+          "type": "SYMBOL",
+          "name": "literal"
+        },
         {
           "type": "SYMBOL",
           "name": "identifier_pattern"
+        }
+      ]
+    },
+    "simple_pattern": {
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "SYMBOL",
+          "name": "wildcard_pattern"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "tuple_pattern"
         },
         {
           "type": "SYMBOL",
           "name": "literal"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "identifier_pattern"
         }
       ]
     },
@@ -2830,10 +2973,6 @@
       "rust_path",
       "expression"
     ],
-    [
-      "struct_pattern",
-      "expression"
-    ],
     [
       "html_element"
     ],

src/node-types.json

@@ -67,6 +67,67 @@
       ]
     }
   },
+  {
+    "type": "attribute_control_flow",
+    "named": true,
+    "fields": {},
+    "children": {
+      "multiple": false,
+      "required": true,
+      "types": [
+        {
+          "type": "attribute_for_loop",
+          "named": true
+        },
+        {
+          "type": "attribute_if_statement",
+          "named": true
+        }
+      ]
+    }
+  },
+  {
+    "type": "attribute_for_loop",
+    "named": true,
+    "fields": {},
+    "children": {
+      "multiple": true,
+      "required": true,
+      "types": [
+        {
+          "type": "attribute_or_control",
+          "named": true
+        },
+        {
+          "type": "expression",
+          "named": true
+        },
+        {
+          "type": "simple_pattern",
+          "named": true
+        }
+      ]
+    }
+  },
+  {
+    "type": "attribute_if_statement",
+    "named": true,
+    "fields": {},
+    "children": {
+      "multiple": true,
+      "required": true,
+      "types": [
+        {
+          "type": "attribute_or_control",
+          "named": true
+        },
+        {
+          "type": "expression",
+          "named": true
+        }
+      ]
+    }
+  },
   {
     "type": "attribute_list",
     "named": true,
@@ -82,6 +143,25 @@
       ]
     }
   },
+  {
+    "type": "attribute_or_control",
+    "named": true,
+    "fields": {},
+    "children": {
+      "multiple": false,
+      "required": true,
+      "types": [
+        {
+          "type": "attribute_control_flow",
+          "named": true
+        },
+        {
+          "type": "html_attribute",
+          "named": true
+        }
+      ]
+    }
+  },
   {
     "type": "attribute_reference",
     "named": true,
@@ -542,7 +622,7 @@
           "named": true
         },
         {
-          "type": "pattern",
+          "type": "simple_pattern",
           "named": true
         }
       ]
@@ -718,7 +798,7 @@
       "required": true,
       "types": [
         {
-          "type": "html_attribute",
+          "type": "attribute_or_control",
           "named": true
         },
         {
@@ -1230,6 +1310,33 @@
       ]
     }
   },
+  {
+    "type": "simple_pattern",
+    "named": true,
+    "fields": {},
+    "children": {
+      "multiple": false,
+      "required": true,
+      "types": [
+        {
+          "type": "identifier_pattern",
+          "named": true
+        },
+        {
+          "type": "literal",
+          "named": true
+        },
+        {
+          "type": "tuple_pattern",
+          "named": true
+        },
+        {
+          "type": "wildcard_pattern",
+          "named": true
+        }
+      ]
+    }
+  },
   {
     "type": "slice_type",
     "named": true,