Macro repetition pattern '?' (#62)

* Allow zero-or-one repetition pattern

* Update test to include new repetition pattern

Author: GrayJack

corpus/macros.txt

@@ -65,32 +65,80 @@ macro_rules! o_O {
     }
 }
 
+macro_rules! zero_or_one {
+    ($($e:expr),?) => {
+        $($e),?
+    };
+}
+
 ----
 
 (source_file
-  (macro_definition (identifier)
+  (macro_definition
+    name: (identifier)
     (macro_rule
-      (token_tree_pattern)
-      (token_tree (identifier) (token_tree (string_literal)))))
-  (macro_definition (identifier)
+      left: (token_tree_pattern)
+      right: (token_tree
+        (identifier)
+        (token_tree
+          (string_literal)))))
+  (macro_definition
+    name: (identifier)
     (macro_rule
-      (token_tree_pattern)
-      (token_tree (integer_literal) (integer_literal))))
-  (macro_definition (identifier)
+      left: (token_tree_pattern)
+      right: (token_tree
+        (integer_literal)
+        (integer_literal))))
+  (macro_definition
+    name: (identifier)
     (macro_rule
-      (token_tree_pattern (identifier) (token_binding_pattern (metavariable) (fragment_specifier)))
-      (token_tree
-        (identifier) (token_tree (string_literal) (metavariable))))
+      left: (token_tree_pattern
+        (identifier)
+        (token_binding_pattern
+          name: (metavariable)
+          type: (fragment_specifier)))
+      right: (token_tree
+        (identifier)
+        (token_tree
+          (string_literal)
+          (metavariable))))
     (macro_rule
-      (token_tree_pattern
+      left: (token_tree_pattern
+        (identifier)
+        (token_binding_pattern
+          name: (metavariable)
+          type: (fragment_specifier)))
+      right: (token_tree
         (identifier)
-        (token_binding_pattern (metavariable) (fragment_specifier)))
-      (token_tree
-        (identifier) (token_tree (string_literal) (metavariable)))))
-  (macro_definition (identifier)
+        (token_tree
+          (string_literal)
+          (metavariable)))))
+  (macro_definition
+    name: (identifier)
+    (macro_rule
+      left: (token_tree_pattern
+        (token_repetition_pattern
+          (token_binding_pattern
+            name: (metavariable)
+            type: (fragment_specifier))
+          (token_tree_pattern
+            (token_repetition_pattern
+              (token_binding_pattern
+                name: (metavariable)
+                type: (fragment_specifier))))))
+      right: (token_tree
+        (token_repetition
+          (token_repetition
+            (metavariable)
+            (metavariable))))))
+  (macro_definition
+    name: (identifier)
     (macro_rule
-      (token_tree_pattern (token_repetition_pattern
-        (token_binding_pattern (metavariable) (fragment_specifier))
-        (token_tree_pattern (token_repetition_pattern
-          (token_binding_pattern (metavariable) (fragment_specifier))))))
-      (token_tree (token_repetition (token_repetition (metavariable) (metavariable)))))))
+      left: (token_tree_pattern
+        (token_repetition_pattern
+          (token_binding_pattern
+            name: (metavariable)
+            type: (fragment_specifier))))
+      right: (token_tree
+        (token_repetition
+          (metavariable))))))

grammar.js

@@ -163,7 +163,7 @@ module.exports = grammar({
     )),
 
     token_repetition_pattern: $ => seq(
-      '$', '(', repeat($._token_pattern), ')', optional(/[^+*]+/), choice('+', '*')
+      '$', '(', repeat($._token_pattern), ')', optional(/[^+*?]+/), choice('+', '*', '?')
     ),
 
     fragment_specifier: $ => choice(
@@ -183,7 +183,7 @@ module.exports = grammar({
     ),
 
     token_repetition: $ => seq(
-      '$', '(', repeat($._tokens), ')', optional(/[^+*]+/), choice('+', '*')
+      '$', '(', repeat($._tokens), ')', optional(/[^+*?]+/), choice('+', '*', '?')
     ),
 
     _non_special_token: $ => choice(

src/grammar.json

@@ -426,7 +426,7 @@
           "members": [
             {
               "type": "PATTERN",
-              "value": "[^+*]+"
+              "value": "[^+*?]+"
             },
             {
               "type": "BLANK"
@@ -443,6 +443,10 @@
             {
               "type": "STRING",
               "value": "*"
+            },
+            {
+              "type": "STRING",
+              "value": "?"
             }
           ]
         }
@@ -602,7 +606,7 @@
           "members": [
             {
               "type": "PATTERN",
-              "value": "[^+*]+"
+              "value": "[^+*?]+"
             },
             {
               "type": "BLANK"
@@ -619,6 +623,10 @@
             {
               "type": "STRING",
               "value": "*"
+            },
+            {
+              "type": "STRING",
+              "value": "?"
             }
           ]
         }
@@ -735,7 +743,7 @@
         },
         {
           "type": "PATTERN",
-          "value": "[\\/_\\-=->,;:::!=?.@*=\\/='&=#%=^=+<>|~]+"
+          "value": "[/_\\-=->,;:::!=?.@*=/='&=#%=^=+<>|~]+"
         },
         {
           "type": "STRING",