From e8bf0dc0bbfb47547ed006a853e841fab23ed057 Mon Sep 17 00:00:00 2001
From: Jon Skeet <skeet@pobox.com>
Date: Thu, 24 Jun 2021 17:25:06 +0100
Subject: [PATCH] Parse (and format) ANTLR fragment productions in the Word
 converter

This should enable #339 and #342 in terms of Word conversion.
---
 tools/MarkdownConverter/Grammar/Antlr.cs      | 16 +++++++++++++++-
 tools/MarkdownConverter/Grammar/Production.cs |  7 ++++++-
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/tools/MarkdownConverter/Grammar/Antlr.cs b/tools/MarkdownConverter/Grammar/Antlr.cs
index 622e96de2..59da095f5 100644
--- a/tools/MarkdownConverter/Grammar/Antlr.cs
+++ b/tools/MarkdownConverter/Grammar/Antlr.cs
@@ -167,6 +167,10 @@ private static IEnumerable<ColorizedWord> ColorizeAntlr(Production p)
             }
             else
             {
+                if (p.Fragment)
+                {
+                    yield return Col("fragment ", "PlainText");
+                }
                 yield return Col(p.Name, "Production");
                 yield return Col(":", "PlainText");
                 if (p.RuleStartsOnNewLine) { yield return null; yield return Col("\t| ", "PlainText"); }
@@ -343,6 +347,16 @@ private static IEnumerable<Production> ReadInternal(string src)
                 }
                 else
                 {
+                    bool fragment = t == "fragment";
+                    if (fragment)
+                    {
+                        while (tokens.Any() && string.IsNullOrWhiteSpace(tokens.First.Value))
+                        {
+                            tokens.RemoveFirst();
+                        }
+                        t = tokens.First.Value;
+                        tokens.RemoveFirst();
+                    }
                     var whitespace = "";
                     var comment = "";
                     var newline = false;
@@ -375,7 +389,7 @@ private static IEnumerable<Production> ReadInternal(string src)
                         tokens.RemoveFirst();
                     }
 
-                    var production = new Production { Comment = comment, Ebnf = p, Name = t, RuleStartsOnNewLine = newline };
+                    var production = new Production { Fragment = fragment, Comment = comment, Ebnf = p, Name = t, RuleStartsOnNewLine = newline };
                     while (tokens.Any() && tokens.First.Value.StartsWith("//"))
                     {
                         production.Comment += tokens.First.Value.Substring(2); tokens.RemoveFirst();
diff --git a/tools/MarkdownConverter/Grammar/Production.cs b/tools/MarkdownConverter/Grammar/Production.cs
index 55fd09379..4e998dc9b 100644
--- a/tools/MarkdownConverter/Grammar/Production.cs
+++ b/tools/MarkdownConverter/Grammar/Production.cs
@@ -7,6 +7,11 @@ internal class Production
         /// </summary>
         public EbnfNode Ebnf { get; set; }
 
+        /// <summary>
+        /// Whether or not this production is a fragment
+        /// </summary>
+        public bool Fragment { get; set; }
+
         /// <summary>
         /// Optional. Contains no whitespace and is not delimited by '
         /// </summary>
@@ -32,6 +37,6 @@ internal class Production
         /// </summary>
         public string LinkName { get; set; }
 
-        public override string ToString() => $"{Name} := {Ebnf}";
+        public override string ToString() => $"{(Fragment ? "fragment " : "")}{Name} := {Ebnf}";
     }
 }