Allow discards in enums (syntax only)

Abc-Arbitrage · May 9, 2024 · b3f0037 · b3f0037
1 parent 980fab9
commit b3f0037
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Showing 5 changed files with 34 additions and 0 deletions.
diff --git a/src/Abc.Zebus.MessageDsl/Analysis/AstCreationVisitor.cs b/src/Abc.Zebus.MessageDsl/Analysis/AstCreationVisitor.cs
@@ -148,6 +148,20 @@ public AstCreationVisitor(ParsedContracts contracts)
 
         foreach (var enumMemberContext in context.enumMember())
         {
+            if (enumMemberContext.discard is not null)
+            {
+                enumDef.Members.Add(
+                    new EnumMemberDefinition
+                    {
+                        ParseContext = enumMemberContext,
+                        Name = "_",
+                        IsDiscarded = true
+                    }
+                );
+
+                continue;
+            }
+
             var memberDef = new EnumMemberDefinition
             {
                 ParseContext = enumMemberContext,

diff --git a/src/Abc.Zebus.MessageDsl/Analysis/AstProcessor.cs b/src/Abc.Zebus.MessageDsl/Analysis/AstProcessor.cs
@@ -46,6 +46,9 @@ public void Cleanup()
     {
         foreach (var message in _contracts.Messages)
             RemoveDiscardedParameters(message);
+
+        foreach (var enumDef in _contracts.Enums)
+            RemoveDiscardedMembers(enumDef);
     }
 
     private static void AddInterfaces(MessageDefinition message)
@@ -146,6 +149,15 @@ private static void RemoveDiscardedParameters(MessageDefinition message)
         }
     }
 
+    private static void RemoveDiscardedMembers(EnumDefinition enumDef)
+    {
+        for (var i = enumDef.Members.Count - 1; i >= 0; --i)
+        {
+            if (enumDef.Members[i].IsDiscarded)
+                enumDef.Members.RemoveAt(i);
+        }
+    }
+
     private static void AddReservations(MessageDefinition message)
     {
         var currentReservation = ReservationRange.None;

diff --git a/src/Abc.Zebus.MessageDsl/Analysis/AstValidator.cs b/src/Abc.Zebus.MessageDsl/Analysis/AstValidator.cs
@@ -158,6 +158,9 @@ private void ValidateEnum(EnumDefinition enumDef)
 
         foreach (var member in enumDef.Members)
         {
+            if (member.IsDiscarded)
+                continue;
+
             if (!definedMembers.Add(member.Name))
                 _contracts.AddError(member.ParseContext, $"Duplicate enum member: {member.Name}");
 

diff --git a/src/Abc.Zebus.MessageDsl/Ast/EnumMemberDefinition.cs b/src/Abc.Zebus.MessageDsl/Ast/EnumMemberDefinition.cs
@@ -6,4 +6,8 @@ public class EnumMemberDefinition : AstNode, INamedNode
     public string? Value { get; set; }
     public AttributeSet Attributes { get; } = new();
     internal int? ProtoValue { get; set; }
+    internal bool IsDiscarded { get; set; }
+
+    public override string ToString()
+        => Name;
 }
diff --git a/src/Abc.Zebus.MessageDsl/Dsl/MessageContracts.g4 b/src/Abc.Zebus.MessageDsl/Dsl/MessageContracts.g4
@@ -44,6 +44,7 @@ enumDefinition
 
 enumMember
 	:	attributes name=id ('=' value=enumValue)?
+	|	discard=DISCARD
 	;
 
 enumValue