Refactor Parser States

Refactor the class hierarchy for parser states so that
there is a parser state that acts more like a type and
one that acts more like a value (the latter, then, serves
as the base class for the other instantiated parser states).

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

Sources/P4Runtime/Expressions.swift

@@ -24,8 +24,7 @@ extension SelectCaseExpression: EvaluatableExpression {
   }
 
   public func type() -> any Common.P4Type {
-    // TODO
-    return reject
+    return ParserState()
   }
 }
 
@@ -46,9 +45,8 @@ extension SelectExpression: EvaluatableExpression {
     }
   }
 
-  // TODO
   public func type() -> any Common.P4Type {
-    return reject
+    return ParserState()
   }
 }
 

Sources/P4Runtime/Parser.swift

@@ -118,11 +118,11 @@ extension ParserStateSelectTransition: EvaluatableParserState {
 }
 
 extension Parser: ParserExecution {
-  public func execute(execution: ProgramExecution) -> (ParserState, ProgramExecution) {
+  public func execute(execution: ProgramExecution) -> (InstantiatedParserState, ProgramExecution) {
     var execution = execution.enter_scope()
 
-    execution = execution.declare(identifier: accept.state().state, withValue: accept)
-    execution = execution.declare(identifier: reject.state().state, withValue: reject)
+    execution = execution.declare(identifier: AsInstantiatedParserState(accept.state()).state, withValue: accept)
+    execution = execution.declare(identifier: AsInstantiatedParserState(reject.state()).state, withValue: reject)
 
     // Add initial values to the global scope
     if let initial = execution.initial_values() {
@@ -148,6 +148,6 @@ extension Parser: ParserExecution {
     while !current_state.done() && !execution.hasError() {
       (current_state, execution) = current_state.execute(program: execution)
     }
-    return (current_state.state(), execution)
+    return (AsInstantiatedParserState(current_state.state()), execution)
   }
 }

Sources/P4Runtime/Protocols.swift

@@ -35,5 +35,5 @@ public protocol EvaluatableParserState: P4Value {
 }
 
 public protocol ParserExecution {
-  func execute(execution: ProgramExecution) -> (ParserState, ProgramExecution)
+  func execute(execution: ProgramExecution) -> (InstantiatedParserState, ProgramExecution)
 }