Allow macro invocations in patterns (#143)

* Allow macro invocations in patterns

* Regenerate parser files

* Update corpus

* Add additional test case for macro invocations in patterns

Co-authored-by: ky <>

Author: kyrime

corpus/expressions.txt

@@ -613,10 +613,11 @@ let msg = match x {
             (integer_literal))
           value: (string_literal))
         (match_arm
-          pattern: (macro_invocation
-            macro: (identifier)
-            (token_tree
-              (integer_literal)))
+          pattern: (match_pattern
+            (macro_invocation
+              macro: (identifier)
+              (token_tree
+                (integer_literal))))
           value: (string_literal))
         (match_arm
           pattern: (match_pattern)

corpus/patterns.txt

@@ -243,6 +243,8 @@ let ref mut x @ (A | B | C);
 
 fn foo((1 | 2 | 3): u8) {}
 
+if let x!() | y!() = () {}
+
 // Discomment after box pattern land on master
 // let box (A | B | C);
 
@@ -366,6 +368,17 @@ fn foo((1 | 2 | 3): u8) {}
             (integer_literal)))
         type: (primitive_type)))
     body: (block))
+  (expression_statement
+    (if_let_expression
+      pattern: (or_pattern
+        (macro_invocation
+          macro: (identifier)
+          (token_tree))
+        (macro_invocation
+          macro: (identifier)
+          (token_tree)))
+      value: (unit_expression)
+      consequence: (block)))
   (line_comment)
   (line_comment)
   (line_comment)

grammar.js

@@ -1216,10 +1216,7 @@ module.exports = grammar({
 
     match_arm: $ => seq(
       repeat($.attribute_item),
-      field('pattern', choice(
-        $.macro_invocation,
-        $.match_pattern
-      )),
+      field('pattern', $.match_pattern),
       '=>',
       choice(
         seq(field('value', $._expression), ','),
@@ -1358,6 +1355,7 @@ module.exports = grammar({
       $.range_pattern,
       $.or_pattern,
       $.const_block,
+      $.macro_invocation,
       '_'
     ),
 

src/grammar.json

@@ -768,7 +768,7 @@
         },
         {
           "type": "PATTERN",
-          "value": "[/_\\-=->,;:::!=?.@*&#%^+<>|~]+"
+          "value": "[\\/_\\-=->,;:::!=?.@*&#%^+<>|~]+"
         },
         {
           "type": "STRING",
@@ -7101,17 +7101,8 @@
           "type": "FIELD",
           "name": "pattern",
           "content": {
-            "type": "CHOICE",
-            "members": [
-              {
-                "type": "SYMBOL",
-                "name": "macro_invocation"
-              },
-              {
-                "type": "SYMBOL",
-                "name": "match_pattern"
-              }
-            ]
+            "type": "SYMBOL",
+            "name": "match_pattern"
           }
         },
         {
@@ -7967,6 +7958,10 @@
           "type": "SYMBOL",
           "name": "const_block"
         },
+        {
+          "type": "SYMBOL",
+          "name": "macro_invocation"
+        },
         {
           "type": "STRING",
           "value": "_"

src/node-types.json

@@ -343,6 +343,10 @@
         "type": "identifier",
         "named": true
       },
+      {
+        "type": "macro_invocation",
+        "named": true
+      },
       {
         "type": "mut_pattern",
         "named": true
@@ -2642,10 +2646,6 @@
         "multiple": false,
         "required": true,
         "types": [
-          {
-            "type": "macro_invocation",
-            "named": true
-          },
           {
             "type": "match_pattern",
             "named": true