Add extended enum syntax, allowing assignment of enum values upon dec…

…laration

Signed-off-by: QiuFeng54321 <[email protected]>

PseudoCode.Core/Parsing/PseudoCode.g4

@@ -143,7 +143,8 @@ argumentDeclaration: (Byval | Byref)? Identifier Colon dataType;
 tuple: expression (Comma expression)*;
 
 enumDefinition: Type name=Identifier Equal OpenParen enumBody CloseParen;
-enumBody: Identifier (Comma Identifier)*;
+enumBody: enumItem (Comma enumItem)*;
+enumItem: Identifier (Equal integer)?;
 typeAliasDefinition: Type Identifier Equal dataType;
 typeDefinition: Type Identifier typeBody Endtype;
 typeBody: INDENT typeChild+ DEDENT;

PseudoCode.Core/Parsing/PseudoCodeBaseListener.cs

@@ -415,6 +415,18 @@ public virtual void EnterEnumBody([NotNull] PseudoCodeParser.EnumBodyContext con
 	/// <param name="context">The parse tree.</param>
 	public virtual void ExitEnumBody([NotNull] PseudoCodeParser.EnumBodyContext context) { }
 	/// <summary>
+	/// Enter a parse tree produced by <see cref="PseudoCodeParser.enumItem"/>.
+	/// <para>The default implementation does nothing.</para>
+	/// </summary>
+	/// <param name="context">The parse tree.</param>
+	public virtual void EnterEnumItem([NotNull] PseudoCodeParser.EnumItemContext context) { }
+	/// <summary>
+	/// Exit a parse tree produced by <see cref="PseudoCodeParser.enumItem"/>.
+	/// <para>The default implementation does nothing.</para>
+	/// </summary>
+	/// <param name="context">The parse tree.</param>
+	public virtual void ExitEnumItem([NotNull] PseudoCodeParser.EnumItemContext context) { }
+	/// <summary>
 	/// Enter a parse tree produced by <see cref="PseudoCodeParser.typeAliasDefinition"/>.
 	/// <para>The default implementation does nothing.</para>
 	/// </summary>

PseudoCode.Core/Parsing/PseudoCodeCompiler.cs

@@ -738,10 +738,31 @@ public override void ExitTypeAliasDefinition(PseudoCodeParser.TypeAliasDefinitio
     public override void ExitEnumDefinition(PseudoCodeParser.EnumDefinitionContext context)
     {
         base.ExitEnumDefinition(context);
+
+        var autoVal = -1;
+        Dictionary<string, int> enumItems = new();
+        Dictionary<int, string> names = new();
+        foreach (var enumItemContext in context.enumBody().enumItem())
+        {
+            var name = enumItemContext.Identifier().GetText();
+            var valueContext = enumItemContext.integer();
+            var value = valueContext == null ? ++autoVal : autoVal = int.Parse(valueContext.GetText());
+            if (!enumItems.TryAdd(name, value))
+                Program.AnalyserFeedbacks.Add(new Feedback
+                {
+                    Message = $"Duplicate enum name {name}",
+                    Severity = Feedback.SeverityType.Error,
+                    SourceRange = SourceLocationHelper.SourceRange(enumItemContext)
+                });
+
+            names[value] = name;
+        }
+
         CurrentScope.AddOperation(new MakeEnumOperation(CurrentScope, Program)
         {
             Name = context.name.Text,
-            Names = context.enumBody().Identifier().Select(i => i.GetText()).ToList(),
+            Values = enumItems,
+            Names = names,
             PoiLocation = SourceLocationHelper.SourceLocation(context),
             SourceRange = SourceLocationHelper.SourceRange(context)
         });

PseudoCode.Core/Parsing/PseudoCodeListener.cs

@@ -348,6 +348,16 @@ public interface IPseudoCodeListener : IParseTreeListener {
 	/// <param name="context">The parse tree.</param>
 	void ExitEnumBody([NotNull] PseudoCodeParser.EnumBodyContext context);
 	/// <summary>
+	/// Enter a parse tree produced by <see cref="PseudoCodeParser.enumItem"/>.
+	/// </summary>
+	/// <param name="context">The parse tree.</param>
+	void EnterEnumItem([NotNull] PseudoCodeParser.EnumItemContext context);
+	/// <summary>
+	/// Exit a parse tree produced by <see cref="PseudoCodeParser.enumItem"/>.
+	/// </summary>
+	/// <param name="context">The parse tree.</param>
+	void ExitEnumItem([NotNull] PseudoCodeParser.EnumItemContext context);
+	/// <summary>
 	/// Enter a parse tree produced by <see cref="PseudoCodeParser.typeAliasDefinition"/>.
 	/// </summary>
 	/// <param name="context">The parse tree.</param>