Support (One) Local Element

Signed-off-by: Will Hawkins <hawkinsw@obs.cr>

tree-sitter-p4/grammar.js

@@ -29,17 +29,23 @@ export default grammar({
 
         // Common - Parsers
         parserType: $ => seq(optional($.annotations), $.parser, field('parser_name', $.identifier), optional($.typeParameters), '(', optional($.parameterList), ')'),
-        parserLocalElements: $ => choice(seq($.parserLocalElements, $.parserLocalElement)),
-        parserStates: $ => choice($.parserState, seq($.parserStates, $.parserState)),
-        parserState: $ => seq(optional($.annotations), $.state, $.identifier, '{', optional($.parserStatements), $.parserTransitionStatement, $.semicolon, '}'),
-        parserLocalElement: $ => choice($.todo),
+
+        // Mark with higher precedence so that the local states are preferred when parsing!
+        // TODO: Test!
+        parserLocalElements: $ => prec(2, repeat1(seq($.parserLocalElement, $.semicolon))),
+
+        parserStates: $ => repeat1($.parserState),
+        parserState: $ => seq(optional($.annotations), $.state, $.identifier, '{', optional($.parserLocalElements), optional($.parserStatements), $.parserTransitionStatement, $.semicolon, '}'),
+
+        parserLocalElement: $ => choice($.variableDeclaration, $.todo),
+
         selectBody: $ => repeat1(seq($.selectCase, $.semicolon)),
         selectCase: $ => seq($.keysetExpression, $.colon, $.identifier),
 
-        annotations: $ => choice($.annotation, seq($.annotations, $.annotation)),
+        annotations: $ => repeat1($.annotation),
 
         //annotation: $ => choice(seq('@', "[a-z]+"), seq('@', "[a-z]+", '(', $.annotationBody, ')'), seq('@', "[a-z]+", '[', $.structuredAnnotationBody, ']')),
-        annotation: $ => choice(seq('@', "[a-z]+"), seq('@', "[a-z]+", '(', /* empty for now*/ ')'), seq('@', "[a-z]+", '[', /* empty for now */ ']')),
+        annotation: $ => choice(seq('@', "[a-z]+")),// seq('@', "[a-z]+", '(', /* empty for now*/ ')'), seq('@', "[a-z]+", '[', /* empty for now */ ']')),
 
 
         // Declarations
@@ -47,7 +53,9 @@ export default grammar({
 
         // Make separate productions for the parser type and the parser type declaration because the latter can have type parameters.
         parserTypeDeclaration: $ => seq(optional($.annotations), $.parser, field('parser_name', $.identifier), optional($.typeParameters), '(', optional($.parameterList), ')'),
-        parserDeclaration: $ => seq($.parserType, optional($.constructorParameters), '{', seq(optional($.parserLocalElements), $.parserStates), '}'),
+        parserDeclaration: $ => seq($.parserType, optional($.constructorParameters), '{', optional($.parserLocalElements), $.parserStates, '}'),
+
+        variableDeclaration: $ => seq(optional($.annotations), $.typeRef, field('variable_name', $.identifier), optional(seq('=', $.expression))),
 
         // Statements
 

tree-sitter-p4/test/corpus/declarations.txt

@@ -0,0 +1,49 @@
+=========================
+Simple Declaration
+=========================
+parser simple() {
+  state start {
+    bool l;
+    transition accept;
+  }
+};
+
+---
+(p4program
+ (declaration
+  (parserDeclaration
+   (parserType
+    (parser)
+    (identifier)
+   )
+   (parserStates
+    (parserState
+     (state)
+     (identifier)
+     (parserLocalElements
+      (parserLocalElement
+       (variableDeclaration
+        (typeRef
+         (baseType
+          (bool)
+         )
+        )
+        (identifier)
+       )
+      )
+      (semicolon)
+     )
+     (parserTransitionStatement
+      (transition)
+      (transitionSelectionExpression
+       (identifier)
+      )
+     )
+     (semicolon)
+    )
+   )
+  )
+  (semicolon)
+ )
+)
+