From d8f6ff3b0ba5b308127cb47648ea1f65d19a8efc Mon Sep 17 00:00:00 2001
From: Will Hawkins <hawkinsw@obs.cr>
Date: Fri, 30 Jan 2026 08:24:44 -0500
Subject: [PATCH] Update Variable Declarations

Refactor a literal '=' to a production and allow expressions
of string-literal type.

Signed-off-by: Will Hawkins <hawkinsw@obs.cr>
---
 tree-sitter-p4/grammar.js                   |   5 +-
 tree-sitter-p4/test/corpus/declarations.txt | 151 ++++++++++++++++++++
 2 files changed, 154 insertions(+), 2 deletions(-)

diff --git a/tree-sitter-p4/grammar.js b/tree-sitter-p4/grammar.js
index 0268666..2ac59a2 100644
--- a/tree-sitter-p4/grammar.js
+++ b/tree-sitter-p4/grammar.js
@@ -66,7 +66,7 @@ export default grammar({
         parserTypeDeclaration: $ => seq(optional($.annotations), $.parser, field('parser_name', $.identifier), optional($.typeParameters), '(', optional($.parameterList), ')'),
         parserDeclaration: $ => seq($.parserType, optional($.constructorParameters), '{', optional($.parserLocalElements), $.parserStates, '}'),
 
-        variableDeclaration: $ => seq(optional($.annotations), $.typeRef, field('variable_name', $.identifier), optional(seq('=', $.expression))),
+        variableDeclaration: $ => seq(optional($.annotations), $.typeRef, field('variable_name', $.identifier), optional(seq($.assignment, $.expression))),
 
         // Statements
 
@@ -84,7 +84,7 @@ export default grammar({
         parserTransitionStatement: $ => seq($.transition, $.transitionSelectionExpression),
 
         // Expressions
-        expression: $ => choice($.identifier, $.integer, $.true, $.false), // Very limited.
+        expression: $ => choice($.identifier, $.integer, $.true, $.false, $.string_literal), // Very limited.
         selectExpression: $ => seq($.select, '(', $.expression, ')', '{', $.selectBody, '}'), // TODO: Should be expression list and not just a single expression
         transitionSelectionExpression: $ => choice($.identifier, $.selectExpression),
         keysetExpression: $ => $.expression,
@@ -92,6 +92,7 @@ export default grammar({
         // Tokens
         semicolon: $ => ";",
         colon: $ => ":",
+        assignment: $ => "=",
         todo: $ => "todo",
         abstract: $ => "abstract",
         action: $ => "action",
diff --git a/tree-sitter-p4/test/corpus/declarations.txt b/tree-sitter-p4/test/corpus/declarations.txt
index 05f34bc..6ff4f6f 100644
--- a/tree-sitter-p4/test/corpus/declarations.txt
+++ b/tree-sitter-p4/test/corpus/declarations.txt
@@ -47,3 +47,154 @@ parser simple() {
  )
 )
 
+=========================
+Simple Declaration (int)
+=========================
+parser simple() {
+  state start {
+    int l;
+    transition accept;
+  }
+};
+
+---
+(p4program
+ (declaration
+  (parserDeclaration
+   (parserType
+    (parser)
+    (identifier)
+   )
+   (parserStates
+    (parserState
+     (state)
+     (identifier)
+     (parserLocalElements
+      (parserLocalElement
+       (variableDeclaration
+        (typeRef
+         (baseType
+          (int)
+         )
+        )
+        (identifier)
+       )
+      )
+      (semicolon)
+     )
+     (parserTransitionStatement
+      (transition)
+      (transitionSelectionExpression
+       (identifier)
+      )
+     )
+     (semicolon)
+    )
+   )
+  )
+  (semicolon)
+ )
+)
+
+=========================
+Simple Declaration (string)
+=========================
+parser simple() {
+  state start {
+    string l;
+    transition accept;
+  }
+};
+
+---
+(p4program
+ (declaration
+  (parserDeclaration
+   (parserType
+    (parser)
+    (identifier)
+   )
+   (parserStates
+    (parserState
+     (state)
+     (identifier)
+     (parserLocalElements
+      (parserLocalElement
+       (variableDeclaration
+        (typeRef
+         (baseType
+          (string)
+         )
+        )
+        (identifier)
+       )
+      )
+      (semicolon)
+     )
+     (parserTransitionStatement
+      (transition)
+      (transitionSelectionExpression
+       (identifier)
+      )
+     )
+     (semicolon)
+    )
+   )
+  )
+  (semicolon)
+ )
+)
+
+=========================
+Simple Declaration (string with initial value)
+=========================
+parser simple() {
+  state start {
+    string l = "testing";
+    transition accept;
+  }
+};
+
+---
+(p4program
+ (declaration
+  (parserDeclaration
+   (parserType
+    (parser)
+    (identifier)
+   )
+   (parserStates
+    (parserState
+     (state)
+     (identifier)
+     (parserLocalElements
+      (parserLocalElement
+       (variableDeclaration
+        (typeRef
+         (baseType
+          (string)
+         )
+        )
+        (identifier)
+        (assignment)
+        (expression
+         (string_literal)
+        )
+       )
+      )
+      (semicolon)
+     )
+     (parserTransitionStatement
+      (transition)
+      (transitionSelectionExpression
+       (identifier)
+      )
+     )
+     (semicolon)
+    )
+   )
+  )
+  (semicolon)
+ )
+)
+