From b695f4961adbfa7699deee6c857b223d272d934c Mon Sep 17 00:00:00 2001
From: Alexander Luzgarev <mahalex@gmail.com>
Date: Wed, 4 Apr 2018 12:55:17 +0200
Subject: [PATCH] Parse optional commas after switch case identifiers

---
 Parser/MParser.cs       | 31 ++++++++++++++++++++++++++-----
 Parser/SyntaxFactory.cs | 35 +++++++++++++++++++++++++++++++----
 Parser/SyntaxNode.cs    |  5 ++++-
 3 files changed, 61 insertions(+), 10 deletions(-)

diff --git a/Parser/MParser.cs b/Parser/MParser.cs
index 021e8a1..6650842 100644
--- a/Parser/MParser.cs
+++ b/Parser/MParser.cs
@@ -680,8 +680,17 @@ namespace Parser
         {
             var caseKeyword = EatIdentifier("case");
             var caseId = ParseExpression();
+            var commas = new List<TokenNode>();
+            while (CurrentToken.Kind == TokenKind.Comma)
+            {
+                commas.Add(Factory.Token(EatToken()));
+            }
+            if (commas.Count == 0)
+            {
+                commas = null;
+            }
             var statementList = ParseStatements();
-            return Factory.SwitchCase(Factory.Token(caseKeyword), caseId, statementList);
+            return Factory.SwitchCase(Factory.Token(caseKeyword), caseId, statementList, commas);
         }
 
         private SwitchStatementNode ParseSwitchStatement()
@@ -829,10 +838,22 @@ namespace Parser
         {
             var tryKeyword = Factory.Token(EatIdentifier("try"));
             var tryBody = ParseStatements();
-            var catchKeyword = Factory.Token(EatIdentifier("catch"));
-            var catchBody = ParseStatements();
-            var endKeyword = Factory.Token(EatIdentifier("end"));
-            return Factory.TryCatchStatement(tryKeyword, tryBody, catchKeyword, catchBody, endKeyword);
+            if (CurrentToken.PureToken.LiteralText == "catch")
+            {
+                var catchKeyword = Factory.Token(EatIdentifier("catch"));
+                var catchBody = ParseStatements();
+                var endKeyword = Factory.Token(EatIdentifier("end"));
+                return Factory.TryCatchStatement(tryKeyword, tryBody, catchKeyword, catchBody, endKeyword);
+            }
+            else if (CurrentToken.PureToken.LiteralText == "end")
+            {
+                var endKeyword = Factory.Token(EatIdentifier("end"));
+                return Factory.TryCatchStatement(tryKeyword, tryBody, endKeyword);
+            }
+            else
+            {
+                throw new ParsingException($"Unexpected token {CurrentToken.PureToken} while parsing try/catch statement at {CurrentToken.PureToken.Position}.");
+            }
         }
 
         public StatementNode ParseStatementCore()
diff --git a/Parser/SyntaxFactory.cs b/Parser/SyntaxFactory.cs
index 5695c24..ea65f14 100644
--- a/Parser/SyntaxFactory.cs
+++ b/Parser/SyntaxFactory.cs
@@ -154,15 +154,20 @@ namespace Parser
         public SwitchCaseNode SwitchCase(
             TokenNode caseKeyword,
             ExpressionNode caseIdentifier,
-            StatementListNode statementList)
+            StatementListNode statementList,
+            List<TokenNode> optionalCommasAfterIdentifier)
         {
             var children = new List<SyntaxNode>
             {
                 caseKeyword,
-                caseIdentifier,
-                statementList
+                caseIdentifier
             };
-            var result = new SwitchCaseNode(children, caseKeyword, caseIdentifier, statementList);
+            if (optionalCommasAfterIdentifier != null)
+            {
+                children.AddRange(optionalCommasAfterIdentifier);
+            }
+            children.Add(statementList);
+            var result = new SwitchCaseNode(children, caseKeyword, caseIdentifier, statementList, optionalCommasAfterIdentifier);
             SetParent(result);
             return result;
         }
@@ -621,5 +626,27 @@ namespace Parser
             SetParent(result);
             return result;
         }
+
+        public TryCatchStatementNode TryCatchStatement(
+            TokenNode tryKeyword,
+            StatementListNode tryBody,
+            TokenNode endKeyword)
+        {
+            var children = new List<SyntaxNode>
+            {
+                tryKeyword,
+                tryBody,
+                endKeyword
+            };
+            var result = new TryCatchStatementNode(
+                children,
+                tryKeyword,
+                tryBody,
+                null,
+                null,
+                endKeyword);
+            SetParent(result);
+            return result;
+        }
     }
 }
\ No newline at end of file
diff --git a/Parser/SyntaxNode.cs b/Parser/SyntaxNode.cs
index 28aed0c..8c188bc 100644
--- a/Parser/SyntaxNode.cs
+++ b/Parser/SyntaxNode.cs
@@ -245,18 +245,21 @@ namespace Parser
     {
         public TokenNode CaseKeyword { get; }
         public ExpressionNode CaseIdentifier { get; }
+        public List<TokenNode> OptionalCommasAfterIdentifier { get; }
         public StatementListNode StatementList { get; }
 
         public SwitchCaseNode(
             List<SyntaxNode> children,
             TokenNode caseKeyword,
             ExpressionNode caseIdentifier,
-            StatementListNode statementList
+            StatementListNode statementList,
+            List<TokenNode> optionalCommasAfterIdentifier = null
             ) : base(children)
         {
             CaseKeyword = caseKeyword;
             CaseIdentifier = caseIdentifier;
             StatementList = statementList;
+            OptionalCommasAfterIdentifier = optionalCommasAfterIdentifier;
         }
     }