grammar,compiler: Add Support For Fixed-Width Integers

Distinguishing between signed and unsigned fixed-width integer
types must still be done.

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

README.md

@@ -1,12 +1,43 @@
-## P4CE: P4 Continuous Evolution
+## 🏎️ GP4: Generalized P4
 
-_P4CE_[^pronounce]  is a P4 parser and runtime written in Swift that supports an _evolved_ version of P4.
+"P4 is a high-level language for programming protocol-independent packet processors"[^1] and it is awesome. The language is robust and includes many features that make writing
 
-[^pronounce]: The acronym is pronounced "p force".
+- _packet_ parsing pipelines easy to write,
+- _packet_ transformation pipelines easy to write,
+- _packet_ routing pipelines easy to write.
 
-### Evolved How?
+The adjacent ecosystem is great, too: There are now myriad tools available that make it possible to write applications to configure the _packet_ parsing, transformation and routing pipelines written in P4.
 
-Coming soon.
+For example, a developer could use P4 to write code that parses raw bytes received from the network into a structured representation of headers/payloads used to transmit those bytes. A developer could use P4 to write a tool that designates the fields of the parsed packet that a network administrator could name when definining configuration for modifying (or not) a parsed packet and defining configuration about how (even _if_) to route the packet. In such a scenario, the system administrator might use a CLI and write
+
+```console
+PI CLI> table_add ipv4_lpm 10.0.0.1/24 => set_nhop 10.0.0.1 1
+```
+
+which the system running the P4 code written by the developer could read when making a routing decision. Later, if the system administrator wanted to change the way packets were routed, they could use the CLI and write
+
+
+```console
+PI CLI> table_add ipv4_lpm 10.0.0.1/24 => set_nhop 10.0.0.2 1
+```
+
+and the system running the P4 code written by the developer would immediately start to route _packets_ differently.
+
+So, why is _packet_ highlighted?
+
+
+Because we believe that thinking about P4 in exactly the way described above -- after dropping the word _packet_ -- makes it a perfect system for building general-purpose parsing, transformation and routing pipelines. Although there are many ways such tools could be used, we believe that a generalized P4 system would be a perfect candidate for writing online, streaming ETL pipelines (c.f., [Apache Kafka](https://kafka.apache.org/)) or log filter/classification pipelines (c.f., [Sigma](https://sigmahq.io/)).
+
+Our goal is to build generalized P4 (GP4): The best of P4 and a little more. 
+
+Please join us!
+
+[^1]: Pat Bosshart, Dan Daly, Glen Gibb, Martin Izzard, Nick McKeown, Jennifer Rexford, Cole Schlesinger, Dan Talayco, Amin Vahdat, George Varghese, and David Walker. 2014. P4: programming protocol-independent packet processors. SIGCOMM Comput. Commun. Rev. 44, 3 (July 2014), 87–95. https://doi.org/10.1145/2656877.2656890
+
+### Benefits
+
+1. Reuse the extensive existing work from the P4 community.
+2. ... more coming soon.
 
 ### Status
 
@@ -85,13 +116,14 @@ We will try to maintain the following headline format for commit messages:
 where `<component>` is one of:
 
 1. `grammar`: For the tree-sitter-based grammar.
-2. `compiler`: For the Swift-based P4 compiler of tree-sitter-based-parser parsed programs into AST.
-3. `runtime`: For the Swift-based P4 interpreter.
-4. `common`: For any Swift-based components common to the entire project (and macros).
-5. `documentation`: For any documentation updates.
-6. `testing`: For Swift-based tests.
-7. `cli`: For Cli components.
-7. `codegen`: For code generation components.
+1. `compiler`: For the Swift-based P4 compiler of tree-sitter-based-parser parsed programs into AST.
+1. `language`: For the Swift-based AST of a compiled P4 program.
+1. `runtime`: For the Swift-based P4 interpreter.
+1. `common`: For any Swift-based components common to the entire project (and macros).
+1. `documentation`: For any documentation updates.
+1. `testing`: For Swift-based tests.
+1. `cli`: For Cli components.
+1. `codegen`: For code generation components.
 
 where `<subcomponent>` can be more free-form and `<change>` is a pithy description of the changes in the commit.
 

Sources/Common/DataTypes.swift

@@ -424,19 +424,30 @@ public class P4BooleanValue: P4DataValue {
   }
 }
 
+public enum BitWidth: Equatable {
+  case Infinite
+  case Width(Int)
+}
+
 /// A P4 int type
 public struct P4Int: P4Type {
-  public init() {}
+  let width: BitWidth
+
+  public init(_ width: BitWidth = BitWidth.Infinite) {
+    self.width = width
+  }
 
   public var description: String {
-    return "Int"
+    return "Int (width: \(self.width))"
   }
+
   public func eq(rhs: P4Type) -> Bool {
     return switch rhs {
-    case is P4Int: true
+    case let rrhs as P4Int: rrhs.width == self.width
     default: false
     }
   }
+
   public func def() -> P4DataValue? {
     return P4IntValue(withValue: 0)
   }
@@ -444,12 +455,16 @@ public struct P4Int: P4Type {
 
 /// An instance of a P4 integer
 public class P4IntValue: P4DataValue {
+
+  let int_type: P4Int
+
   public func type() -> P4Type {
-    return P4Int()
+    return int_type
   }
 
   let value: Int
-  public init(withValue value: Int) {
+  public init(withValue value: Int, andWidth width: BitWidth = BitWidth.Infinite) {
+    self.int_type = P4Int(width)
     self.value = value
   }
 

Sources/Common/Support.swift

@@ -101,6 +101,8 @@ public func Fold<T, A>(input: [T], initial: A, block: (T, A) -> A) -> A {
   #externalMacro(module: "Macros", type: "RequireNodesType")
 @freestanding(codeItem) public macro SkipUnlessNodeType<N>(node: N, type: String) =
   #externalMacro(module: "Macros", type: "SkipUnlessNodeType")
+@freestanding(codeItem) public macro SkipUnlessNodesTypes<N>(node: N, types: [String]) =
+  #externalMacro(module: "Macros", type: "SkipUnlessNodesTypes")
 
 @freestanding(codeItem) public macro MustOr<E, N>(result: E, thing: E?, or: N) =
   #externalMacro(module: "Macros", type: "MustOr")

Sources/Macros/Macros.swift

@@ -229,6 +229,38 @@ public struct SkipUnlessNodeType: CodeItemMacro {
   }
 }
 
+public struct SkipUnlessNodesTypes: CodeItemMacro {
+  public static func expansion(
+    of node: some FreestandingMacroExpansionSyntax, in context: some MacroExpansionContext
+  ) throws -> [CodeBlockItemSyntax] {
+
+    let arguments = node.arguments.indices
+    var arg_index = arguments.startIndex
+
+    let node_to_check = node.arguments[arg_index].expression
+
+    arg_index = arguments.index(after: arg_index)
+    guard let expected_types = node.arguments[arg_index].expression.as(ArrayExprSyntax.self) else {
+      throw MacroError(withMessage: "Node(s) to check must be in an array")
+    }
+
+    arg_index = arguments.index(after: arg_index)
+
+    let ifs = expected_types.elements.map { l in
+      "\(node_to_check).nodeType != \(l.expression)"
+    }.joined(separator: " && ")
+
+    return [
+      CodeBlockItemSyntax(
+        """
+        if \(raw: ifs) {
+          return Result.Ok(.none)
+        }
+        """)
+    ]
+  }
+}
+
 public struct MustOr: CodeItemMacro {
   public static func expansion(
     of node: some FreestandingMacroExpansionSyntax, in context: some MacroExpansionContext
@@ -261,6 +293,7 @@ public struct MustOr: CodeItemMacro {
 struct P4Macros: CompilerPlugin {
   var providingMacros: [Macro.Type] = [
     RequireResult.self, RequireErrorResult.self, UseOkResult.self, UseErrorResult.self,
-    RequireNodeType.self, SkipUnlessNodeType.self, RequireNodesType.self, MustOr.self,
+    RequireNodeType.self, SkipUnlessNodeType.self, SkipUnlessNodesTypes.self, RequireNodesType.self,
+    MustOr.self,
   ]
 }

Sources/P4Compiler/Expression.swift

@@ -101,9 +101,41 @@ extension P4IntValue: CompilableExpression {
     node: SwiftTreeSitter.Node, withContext context: CompilerContext
   ) -> Result<EvaluatableExpression?> {
     let node = node.child(at: 0)!
-    #SkipUnlessNodeType<SwiftTreeSitter.Node>(node: node, type: "integer")
-    if let parsed_int = Int(node.text!) {
-      return .Ok(P4Value(P4IntValue(withValue: parsed_int)))
+
+    #SkipUnlessNodesTypes<SwiftTreeSitter.Node>(
+      node: node, types: ["integer", "integer_elaborated"])
+
+    var bit_width: BitWidth = BitWidth.Infinite
+    let value_source: String
+    if node.nodeType == "integer_elaborated" {
+      let re = /([0-9]+)([ws])([\-0-9]+)/
+      let integer_components = node.text!.matches(of: re)
+
+      if integer_components.isEmpty || integer_components.count > 1 {
+        return .Error(
+          ErrorWithLocation(
+            sourceLocation: node.toSourceLocation(),
+            withError: "Failed to parse elaborated integer: \(node.text!)"))
+      }
+
+      let width_source = "\(integer_components[0].1)"
+      guard let width = Int(width_source) else {
+        return .Error(
+          ErrorWithLocation(
+            sourceLocation: node.toSourceLocation(),
+            withError: "Failed to parse width from elaborated integer: \(width_source)"))
+      }
+
+      /// TODO: Handle signed vs. unsigned.
+
+      bit_width = BitWidth.Width(width)
+      value_source = "\(integer_components[0].3)"
+    } else {
+      value_source = node.text!
+    }
+
+    if let parsed_int = Int(value_source) {
+      return .Ok(P4Value(P4IntValue(withValue: parsed_int, andWidth: bit_width)))
     } else {
       return .Error(
         ErrorWithLocation(

Sources/P4Compiler/Types.swift

@@ -34,7 +34,42 @@ extension P4Int: CompilableType {
   public static func CompileType(
     type: SwiftTreeSitter.Node, withContext: CompilerContext
   ) -> Common.Result<(any Common.P4Type)?> {
-    return type.text == "int" ? .Ok(P4Int()) : .Ok(.none)
+
+    // Drill down, as appropriate.
+    let base_type_node = type.child(at: 0)!
+    #SkipUnlessNodeType<SwiftTreeSitter.Node>(
+      node: base_type_node, type: "baseType")
+
+    let type_node = base_type_node.child(at: 0)!
+    #SkipUnlessNodeType<SwiftTreeSitter.Node>(
+      node: type_node, type: "int_type")
+
+    var walker = Walker(node: type_node)
+
+    var int_node: Node? = .none
+
+    #MustOr(
+      result: int_node, thing: walker.getNext(),
+      or: Result<P4Type?>.Error(
+        ErrorWithLocation(
+          sourceLocation: type_node.toSourceLocation(),
+          withError: "Missing elements in int type declaration")))
+
+    // Move passed the keyword.
+    walker.next()
+
+    if let bit_width_node = walker.getNext() {
+      guard let bit_width = Int(bit_width_node.child(at: 1)!.text!),
+        bit_width != 0
+      else {
+        return .Error(
+          ErrorWithLocation(
+            sourceLocation: bit_width_node.toSourceLocation(),
+            withError: "Could not parse \(bit_width_node.text!) into integer"))
+      }
+      return .Ok(P4Int(BitWidth.Width(bit_width)))
+    }
+    return .Ok(P4Int())
   }
 }
 

Sources/P4Lang/Types.swift

@@ -1,28 +0,0 @@
-// p4rse, Copyright 2026, Will Hawkins
-//
-// This file is part of p4rse.
-//
-// This file is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program. If not, see <https://www.gnu.org/licenses/>.
-
-import Common
-
-public struct AttributedP4Type {
-  public let type: P4Type
-  public let attributes: P4QualifiedType
-
-  public init(_ type: P4Type, _ attributes: P4QualifiedType) {
-    self.type = type
-    self.attributes = attributes
-  }
-}

Sources/P4Runtime/CodeGen.swift

@@ -17,6 +17,7 @@
 
 import Common
 import P4Lang
+import P4Protos
 
 public struct Generated {
   let gen: String
@@ -48,13 +49,12 @@ public struct CodeGenerator: LanguageVisitor {
     return visitor.start(node, context: generated)
   }
 
-  /// TODO: Can we generate these implementations somehow?
-
   public typealias Context = Generated
 
   public func visit(
     _ v: Program, _ c: VisitorContext<Generated>
   ) -> Result<VisitorContext<Generated>> {
+
     var result: Result<VisitorContext<Generated>> = Fold(
       input: v.types, initial: .Ok(c.next(uc: c.getUserContext().append("[")))
     ) { (current, acc) in

Tests/p4rseTests/ControlTests/Compile.swift

@@ -283,7 +283,7 @@ import P4Lang
     #RequireErrorResult(
       Error(
         withMessage:
-          "{57, 10}: Failed to parse a statement element: {57, 1}: Cannot assign value with type Boolean to identifier z with type Int"
+          "{57, 10}: Failed to parse a statement element: {57, 1}: Cannot assign value with type Boolean to identifier z with type Int (width: Infinite)"
       ),
       Program.Compile(simple_parser_declaration))
   )

Tests/p4rseTests/ExpressionTests/FunctionCall.swift

@@ -182,5 +182,5 @@ import TreeSitterP4
 
   let error = try #UseErrorResult(Program.Compile(simple_parser_declaration))
 
-  #expect(error.msg().contains("{29, 12}: Type of expression in return statement (Boolean) is not compatible with function return type (Int)"))
+  #expect(error.msg().contains("{29, 12}: Type of expression in return statement (Boolean) is not compatible with function return type (Int (width: Infinite))"))
 }

Tests/p4rseTests/ExpressionTests/SelectExpression.swift

@@ -132,7 +132,7 @@ import TreeSitterP4
     #RequireErrorResult(
       Error(
         withMessage:
-        "Error(s) parsing select cases: {81, 4}: Key expression of type Boolean is not compatible with selector type Int"
+        "Error(s) parsing select cases: {81, 4}: Key expression of type Boolean is not compatible with selector type Int (width: Infinite)"
       ),
       Program.Compile(simple_parser_declaration)))
 }

Tests/p4rseTests/RuntimeTests.swift

@@ -147,7 +147,7 @@ import TreeSitterP4
 
   #expect(
     #RequireErrorResult<(InstantiatedParserState, ProgramExecution)>(
-      Error(withMessage: "Cannot call parser: Argument 1's type (Int) is incompatible with the parameter type (Boolean)"),
+      Error(withMessage: "Cannot call parser: Argument 1's type (Int (width: Infinite)) is incompatible with the parameter type (Boolean)"),
       runtime.run(withArguments: args)))
 }
 

Tests/p4rseTests/StructTests.swift

@@ -327,7 +327,7 @@ import TreeSitterP4
   #expect(
     #RequireErrorResult(
       Error(
-        withMessage: "{49, 13}: Failed to parse a statement element: {49, 8}: Cannot assign value of type Int to field yesno of type Boolean"
+        withMessage: "{49, 13}: Failed to parse a statement element: {49, 8}: Cannot assign value of type Int (width: Infinite) to field yesno of type Boolean"
       ),
       Program.Compile(simple_parser_declaration, withGlobalInstances: test_declarations))
   )
@@ -457,7 +457,7 @@ import TreeSitterP4
   #expect(
     #RequireErrorResult(
       Error(
-        withMessage: "{49, 20}: Failed to parse a statement element: {49, 11}: Cannot assign value of type Boolean to field count of type Int"
+        withMessage: "{49, 20}: Failed to parse a statement element: {49, 11}: Cannot assign value of type Boolean to field count of type Int (width: Infinite)"
       ),
       Program.Compile(simple_parser_declaration, withGlobalInstances: test_declarations))
   )

Tests/p4rseTests/SupportTests.swift

@@ -45,5 +45,5 @@ struct StringConvertible: CustomStringConvertible {
 
 @Test func test_result_type_p4value_convertible() async throws {
     let result = Result.Ok(P4Value(P4IntValue(withValue: 5)))
-    #expect("\(result)" == "Ok: Value: 5 of Int type of type Int")
+    #expect("\(result)" == "Ok: Value: 5 of Int (width: Infinite) type of type Int (width: Infinite)")
 }

Tests/p4rseTests/ValueTypeParserTests.swift

@@ -18,8 +18,8 @@
 import Common
 import Foundation
 import Macros
-import P4Runtime
 import P4Lang
+import P4Runtime
 import SwiftTreeSitter
 import Testing
 import TreeSitter
@@ -36,13 +36,15 @@ import TreeSitterP4
               transition reject;
             }
           };
-      """;
+      """
 
     let err = Program.Compile(simple_parser_declaration)
     guard case Result.Error(let e) = err else {
       assert(false, "Expected an error, but had success")
     }
-    #expect(e.msg().contains("Failed to parse a statement element: Could not parse a P4 type from \(invalid_type_name)"))
+    #expect(
+      e.msg().contains(
+        "Failed to parse a statement element: Could not parse a P4 type from \(invalid_type_name)"))
   }
 }
 
@@ -62,7 +64,7 @@ import TreeSitterP4
     #RequireErrorResult(
       Error(
         withMessage:
-        "{112, 16}: Failed to parse a statement element: {112, 8}: Cannot assign value with type Boolean to identifier where_to with type String"
+          "{112, 16}: Failed to parse a statement element: {112, 8}: Cannot assign value with type Boolean to identifier where_to with type String"
       ),
       Program.Compile(simple_parser_declaration)))
 }
@@ -83,7 +85,7 @@ import TreeSitterP4
     #RequireErrorResult(
       Error(
         withMessage:
-        "{114, 22}: Failed to parse a statement element: {114, 8}: Cannot assign value with type String to identifier where_to with type Boolean"
+          "{114, 22}: Failed to parse a statement element: {114, 8}: Cannot assign value with type String to identifier where_to with type Boolean"
       ),
       Program.Compile(simple_parser_declaration)))
 }
@@ -128,6 +130,90 @@ import TreeSitterP4
       Program.Compile(simple_parser_declaration)))
 }
 
+@Test func test_invalid_type_in_declaration3() async throws {
+  let simple_parser_declaration = """
+      parser main_parser() {
+        state start {
+          int<5> specific_width_int = 5;
+          int unspecific_width_int = specific_width_int;
+          transition reject;
+        }
+      };
+    """
+
+  let error = try! #UseErrorResult(Program.Compile(simple_parser_declaration))
+
+  #expect(
+    error.msg().contains(
+      "Cannot initialize specific_width_int (with type Int (width: Width(5))) from expression with type Int (width: Infinite)"
+    ))
+}
+
+@Test func test_valid_specific_width_int_type_in_declaration() async throws {
+  let simple_parser_declaration = """
+      parser main_parser() {
+        state start {
+          int<5> specific_width_int = 5w5;
+          int<5> unspecific_width_int = specific_width_int;
+          transition reject;
+        }
+      };
+    """
+
+  #expect(#RequireOkResult(Program.Compile(simple_parser_declaration)))
+}
+
+@Test func test_expression_in_declaration_initializer_specific_width_int_type() async throws {
+  let simple_parser_declaration = """
+      parser main_parser() {
+        state start {
+          int<5> specific_width_int = 5w5;
+          bool where_to = 5w5 == specific_width_int == true;
+          transition select (where_to) {
+            true: accept;
+            false: reject;
+          };
+        }
+      };
+    """
+
+  let program = try #UseOkResult(Program.Compile(simple_parser_declaration))
+  let runtime = try #UseOkResult(
+    P4Runtime.Runtime<InstantiatedParserState, P4Lang.Parser>.create(program: program))
+  let (state_result, _) = try! #UseOkResult(runtime.run())
+
+  // 5w5 == specific_width_int == true
+  // true == true
+  // true
+  #expect(AsInstantiatedParserState(state_result) == P4Lang.accept)
+}
+
+@Test func test_expression_in_declaration_initializer_specific_width_int_type2() async throws {
+  let simple_parser_declaration = """
+      parser main_parser() {
+        state start {
+          int<5> specific_width_int = 5w5;
+          bool where_to = 5w6 == specific_width_int == false;
+          transition select (where_to) {
+            true: accept;
+            false: reject;
+          };
+        }
+      };
+    """
+
+  let program = try #UseOkResult(Program.Compile(simple_parser_declaration))
+  let runtime = try #UseOkResult(
+    P4Runtime.Runtime<InstantiatedParserState, P4Lang.Parser>.create(program: program))
+  let (state_result, _) = try! #UseOkResult(runtime.run())
+
+  // 5w6 == specific_width_int == false
+  // false == false
+  // true
+  #expect(AsInstantiatedParserState(state_result) == P4Lang.accept)
+}
+
+
 @Test func test_expression_in_declaration_initializer() async throws {
   let simple_parser_declaration = """
       parser main_parser() {
@@ -141,7 +227,8 @@ import TreeSitterP4
       };
     """
   let program = try #UseOkResult(Program.Compile(simple_parser_declaration))
-  let runtime = try #UseOkResult(P4Runtime.Runtime<InstantiatedParserState, P4Lang.Parser>.create(program: program))
+  let runtime = try #UseOkResult(
+    P4Runtime.Runtime<InstantiatedParserState, P4Lang.Parser>.create(program: program))
   let (state_result, _) = try! #UseOkResult(runtime.run())
 
   // 5 == 5 == true
@@ -163,7 +250,8 @@ import TreeSitterP4
       };
     """
   let program = try #UseOkResult(Program.Compile(simple_parser_declaration))
-  let runtime = try #UseOkResult(P4Runtime.Runtime<InstantiatedParserState, P4Lang.Parser>.create(program: program))
+  let runtime = try #UseOkResult(
+    P4Runtime.Runtime<InstantiatedParserState, P4Lang.Parser>.create(program: program))
   let (state_result, _) = try! #UseOkResult(runtime.run())
 
   // 5 == 5 == true
@@ -185,7 +273,8 @@ import TreeSitterP4
       };
     """
   let program = try #UseOkResult(Program.Compile(simple_parser_declaration))
-  let runtime = try #UseOkResult(P4Runtime.Runtime<InstantiatedParserState, P4Lang.Parser>.create(program: program))
+  let runtime = try #UseOkResult(
+    P4Runtime.Runtime<InstantiatedParserState, P4Lang.Parser>.create(program: program))
   let (state_result, _) = try! #UseOkResult(runtime.run())
 
   // 6 == 5 == true
@@ -207,7 +296,8 @@ import TreeSitterP4
       };
     """
   let program = try #UseOkResult(Program.Compile(simple_parser_declaration))
-  let runtime = try #UseOkResult(P4Runtime.Runtime<InstantiatedParserState, P4Lang.Parser>.create(program: program))
+  let runtime = try #UseOkResult(
+    P4Runtime.Runtime<InstantiatedParserState, P4Lang.Parser>.create(program: program))
   let (state_result, _) = try! #UseOkResult(runtime.run())
 
   // 6 == 5 == false
@@ -229,7 +319,8 @@ import TreeSitterP4
       };
     """
   let program = try #UseOkResult(Program.Compile(simple_parser_declaration))
-  let runtime = try #UseOkResult(P4Runtime.Runtime<InstantiatedParserState, P4Lang.Parser>.create(program: program))
+  let runtime = try #UseOkResult(
+    P4Runtime.Runtime<InstantiatedParserState, P4Lang.Parser>.create(program: program))
   let (state_result, _) = try! #UseOkResult(runtime.run())
 
   // TODO: This test should throw an error.
@@ -253,29 +344,32 @@ import TreeSitterP4
       };
     """
   var test_types = VarTypeScopes().enter()
-  test_types = test_types.declare(identifier: Identifier(name: "ta"), withValue: P4QualifiedType(P4Array(withValueType: P4QualifiedType(P4Int()))))
+  test_types = test_types.declare(
+    identifier: Identifier(name: "ta"),
+    withValue: P4QualifiedType(P4Array(withValueType: P4QualifiedType(P4Int()))))
   #expect(
     #RequireErrorResult(
       Error(
         withMessage:
-          "{49, 22}: Failed to parse a statement element: Cannot initialize where_to (with type Boolean) from expression with type Int"
+          "{49, 22}: Failed to parse a statement element: Cannot initialize where_to (with type Boolean) from expression with type Int (width: Infinite)"
       ),
       Program.Compile(simple_parser_declaration, withGlobalInstances: test_types)))
 }
 
 @Test func test_simple_compiler_parser_parameters_invalid_types() async throws {
   let simple_parser_declaration = """
-    parser main_parser(bool pmtr, string smtr, int imtr) {
-       state start {
-           pmtr = 1;
-           transition accept;
-       }
-    };
-  """
+      parser main_parser(bool pmtr, string smtr, int imtr) {
+         state start {
+             pmtr = 1;
+             transition accept;
+         }
+      };
+    """
   #expect(
     #RequireErrorResult(
       Error(
-        withMessage: "{85, 9}: Failed to parse a statement element: {85, 4}: Cannot assign value with type Int to identifier pmtr with type Boolean"
+        withMessage:
+          "{85, 9}: Failed to parse a statement element: {85, 4}: Cannot assign value with type Int (width: Infinite) to identifier pmtr with type Boolean"
       ),
       Program.Compile(simple_parser_declaration)))
 }

tree-sitter-p4/grammar.js

@@ -40,9 +40,12 @@ export default grammar({
 
         // Common - Types
         typeRef: $ => choice($.baseType, $.type_identifier),
-        baseType: $ => choice($.bool, $.error, $.string, $.int, $.bit /* omitting "templated" types" */),
+        baseType: $ => choice($.bool, $.error, $.string, $.int_type, $.bit /* omitting "templated" types" */),
         constructor_parameters: $ => seq('(', optional($.parameter_list), ')'),
 
+        int_type: $ => seq($.int, optional($.bit_width)),
+        bit_width: $ => seq('<', $.integer, '>'),
+
         // Common - Parsers
         parserType: $ => seq(optional($.annotations), $.parser, field('parser_name', $.identifier), optional($.typeParameters), $.parameters),
 
@@ -120,7 +123,7 @@ export default grammar({
         // Expressions
         expression: $ => choice($.grouped_expression, $.simple_expression),
         grouped_expression: $ => seq('(', $.expression, ')'),
-        simple_expression: $ => choice($.identifier, $.integer, $.booleanLiteralExpression, $.string_literal, $.binaryOperatorExpression, $.arrayAccessExpression, $.fieldAccessExpression, $.function_call), // Very limited.
+        simple_expression: $ => choice($.identifier, $.integer, $.integer_elaborated, $.booleanLiteralExpression, $.string_literal, $.binaryOperatorExpression, $.arrayAccessExpression, $.fieldAccessExpression, $.function_call), // Very limited.
         booleanLiteralExpression: $ => choice($.true, $.false),
         selectExpression: $ => seq($.select, '(', $.expression, ')', '{', $.selectBody, '}'), // TODO: Should be expression list and not just a single expression
         transitionSelectionExpression: $ => choice($.identifier, $.selectExpression),
@@ -211,6 +214,7 @@ export default grammar({
         type_identifier: $ => /[A-Za-z_]+/,
         string_literal: $ => /"[^"]*"/,
         integer: $ => /[0-9]+/,
+        integer_elaborated: $ => /[0-9]+[ws][-0-9]+/,
         annotation_literal: $ => /@[A-Za-z_]+/,
         default_keyset: $=> '_',
 

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

@@ -46,7 +46,7 @@ parser simple() {
 )
 
 =========================
-Simple Declaration (int)
+Simple Declaration (infinite-precision int)
 =========================
 parser simple() {
   state start {
@@ -73,7 +73,9 @@ parser simple() {
        (variableDeclaration
         (typeRef
          (baseType
-          (int)
+          (int_type
+           (int)
+          )
          )
         )
         (identifier)
@@ -92,6 +94,59 @@ parser simple() {
  )
 )
 
+=========================
+Simple Declaration (fixed-precision int)
+=========================
+parser simple() {
+  state start {
+    int<55> l;
+    transition accept;
+  }
+};
+
+---
+(p4program
+ (declaration
+  (parserDeclaration
+   (parserType
+    (parser)
+    (identifier)
+    (parameters)
+   )
+   (parserStates
+    (parserState
+     (state)
+     (identifier)
+     (parserStatements
+      (parserStatement
+       (variableDeclaration
+        (typeRef
+         (baseType
+          (int_type
+           (int)
+           (bit_width
+            (integer)
+           )
+          )
+         )
+        )
+        (identifier)
+       )
+      )
+     )
+     (parserTransitionStatement
+      (transition)
+      (transitionSelectionExpression
+       (identifier)
+      )
+     )
+    )
+   )
+  )
+ )
+)
+
+
 =========================
 Simple Declaration (string)
 =========================
@@ -331,7 +386,9 @@ bool functionb(bool a, int b) {
      (parameter
       (typeRef
        (baseType
-        (int)
+        (int_type
+         (int)
+        )
        )
       )
       (identifier)
@@ -393,7 +450,9 @@ bool functionb(in bool a, out int b, inout string c) {
        )
        (typeRef
         (baseType
-         (int)
+         (int_type
+          (int)
+         )
         )
        )
        (identifier)
@@ -468,7 +527,9 @@ extern bool functionb(in bool a, out int b, inout string c);
          )
          (typeRef
           (baseType
-           (int)
+           (int_type
+            (int)
+           )
           )
          )
          (identifier)

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

@@ -38,7 +38,9 @@ int fun() {
   (function_declaration
    (typeRef
     (baseType
-     (int)
+     (int_type
+      (int)
+     )
     )
    )
    (identifier)
@@ -382,7 +384,9 @@ parser simple() {
        (variableDeclaration
         (typeRef
          (baseType
-          (int)
+          (int_type
+           (int)
+          )
          )
         )
         (identifier)