Merge pull request #280 from tamasvajk/contextual-keywords-var

Add `var` to contextual keywords

corpus/contextual-keywords.txt

@@ -413,3 +413,101 @@ class set { }
   (class_declaration
     (identifier)
     (declaration_list)))
+
+================================================================================
+Var contextual keyword
+================================================================================
+
+void var() { }
+void m(var p) { }
+void m(int var) { }
+void m()
+{
+    var v = null;
+    int var = var;
+    var var = 1;
+
+    var();
+    m(var);
+
+    var x = var + 1;
+}
+
+class var { }
+
+--------------------------------------------------------------------------------
+
+(compilation_unit
+  (global_statement
+    (local_function_statement
+      (predefined_type)
+      (identifier)
+      (parameter_list)
+      (block)))
+  (global_statement
+    (local_function_statement
+      (predefined_type)
+      (identifier)
+      (parameter_list
+        (parameter
+          (implicit_type)
+          (identifier)))
+      (block)))
+  (global_statement
+    (local_function_statement
+      (predefined_type)
+      (identifier)
+      (parameter_list
+        (parameter
+          (predefined_type)
+          (identifier)))
+      (block)))
+  (global_statement
+    (local_function_statement
+      (predefined_type)
+      (identifier)
+      (parameter_list)
+      (block
+        (local_declaration_statement
+          (variable_declaration
+            (implicit_type)
+            (variable_declarator
+              (identifier)
+              (equals_value_clause
+                (null_literal)))))
+        (local_declaration_statement
+          (variable_declaration
+            (predefined_type)
+            (variable_declarator
+              (identifier)
+              (equals_value_clause
+                (identifier)))))
+        (local_declaration_statement
+          (variable_declaration
+            (implicit_type)
+            (variable_declarator
+              (identifier)
+              (equals_value_clause
+                (integer_literal)))))
+        (expression_statement
+          (invocation_expression
+            (identifier)
+            (argument_list)))
+        (expression_statement
+          (invocation_expression
+            (identifier)
+            (argument_list
+              (argument
+                (identifier)))))
+        (local_declaration_statement
+          (variable_declaration
+            (implicit_type)
+            (variable_declarator
+              (identifier)
+              (equals_value_clause
+                (binary_expression
+                  (identifier)
+                  (integer_literal)))))))))
+  (class_declaration
+    (identifier)
+    (declaration_list)))

grammar.js

@@ -72,6 +72,7 @@ module.exports = grammar({
     [$._contextual_keywords, $.scoped_type],
     [$._contextual_keywords, $.scoped_type, $._parameter_type_with_modifiers],
     [$._contextual_keywords, $._parameter_type_with_modifiers],
+    [$._contextual_keywords, $.implicit_type],
 
     [$._type, $.attribute],
     [$._type, $._nullable_base_type],
@@ -228,7 +229,7 @@ module.exports = grammar({
     ),
 
     attribute: $ => seq(
-      field('name', $._name),
+      field('name', $._type_name),
       optional($.attribute_argument_list)
     ),
 
@@ -681,7 +682,7 @@ module.exports = grammar({
     _type: $ => choice(
       $.implicit_type,
       $.array_type,
-      $._name,
+      $._type_name,
       $.nullable_type,
       $.pointer_type,
       $.function_pointer_type,
@@ -691,7 +692,12 @@ module.exports = grammar({
       $.scoped_type,
     ),
 
-    implicit_type: $ => 'var',
+    _type_name: $ => prec.dynamic(0, // `var` could be `_type_name`, but we prefer `implicit_type`
+      $._name
+    ),
+
+    implicit_type: $ => prec.dynamic(1, // Higher precedence than `_type_name`
+      'var'),
 
     array_type: $ => seq(
       field('type', $._array_base_type),
@@ -700,7 +706,7 @@ module.exports = grammar({
 
     _array_base_type: $ => choice(
       $.array_type,
-      $._name,
+      $._type_name,
       $.nullable_type,
       $.pointer_type,
       $.function_pointer_type,
@@ -716,15 +722,15 @@ module.exports = grammar({
 
     _nullable_base_type: $ => choice(
       $.array_type,
-      $._name,
+      $._type_name,
       $.predefined_type,
       $.tuple_type
     ),
 
     pointer_type: $ => seq($._pointer_base_type, '*'),
 
     _pointer_base_type: $ => choice(
-      $._name,
+      $._type_name,
       $.nullable_type,
       $.pointer_type,
       $.function_pointer_type,
@@ -799,7 +805,7 @@ module.exports = grammar({
     _ref_base_type: $ => choice(
       $.implicit_type,
       $.array_type,
-      $._name,
+      $._type_name,
       $.nullable_type,
       $.pointer_type,
       $.function_pointer_type,
@@ -813,7 +819,7 @@ module.exports = grammar({
     ),
 
     _scoped_base_type: $ => choice(
-      $._name,
+      $._type_name,
       $.ref_type,
     ),
 
@@ -1376,7 +1382,7 @@ module.exports = grammar({
     )),
 
     _object_creation_type: $ => choice(
-      $._name,
+      $._type_name,
       $.nullable_type,
       $.predefined_type,
     ),
@@ -1833,7 +1839,7 @@ module.exports = grammar({
       // 'set',
       'unmanaged',
       // 'value',
-      // 'var',
+      'var',
       'when',
       'where',
       // 'with',

script/file_sizes.txt

@@ -1,5 +1,5 @@
-src/grammar.json    	0.2MB	     10861
+src/grammar.json    	0.2MB	     10881
 src/node-types.json 	0.1MB	      7645
-src/parser.c        	49.1MB	   1546389
+src/parser.c        	49.3MB	   1550969
 src/scanner.c       	0.0MB	        29
-total               	49.5MB	   1564924
+total               	49.7MB	   1569524