From 98b9cec1845ecf2e8d7d770557f472638d282a13 Mon Sep 17 00:00:00 2001
From: Josh Goebel <me@joshgoebel.com>
Date: Thu, 6 Feb 2020 16:36:15 -0500
Subject: [PATCH] enh(csharp) generic modifiers, reference paths, `where`
 keyword (#2378)

* enh(csharp) add generic modifiers
* enh(csharp) Allow reference path in class inheritance lists. Closes #1947.
* enh(csharp) Support `where` keyword as class constraint
---
 CHANGES.md                                      |  3 +++
 src/languages/csharp.js                         | 12 ++++++++++--
 test/markup/csharp/generic_modifiers.expect.txt |  7 +++++++
 test/markup/csharp/generic_modifiers.txt        |  7 +++++++
 test/markup/csharp/titles.expect.txt            |  4 +++-
 test/markup/csharp/titles.txt                   |  4 +++-
 6 files changed, 33 insertions(+), 4 deletions(-)
 create mode 100644 test/markup/csharp/generic_modifiers.expect.txt
 create mode 100644 test/markup/csharp/generic_modifiers.txt

diff --git a/CHANGES.md b/CHANGES.md
index 0491d5be76..c12ea5f3ed 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -14,6 +14,9 @@ Core Changes:
 
 Language Improvements:
 
+- enh(csharp) Support `where` keyword as class constraint (#2378) [Josh Goebel][]
+- enh(csharp) Allow reference path in class inheritance lists (#2378) [Josh Goebel][]
+- enh(csharp) Add generic modifiers (in, out) (#2378) [Josh Goebel][]
 - (fortran) enh(fortran) support intrinsic data types (#2379) [Josh Goebel][]
 - enh(java) annotations can include numbers (#2377) [Josh Goebel][]
 - enh(java) annotations can take params (#2377) [Josh Goebel][]
diff --git a/src/languages/csharp.js b/src/languages/csharp.js
index 5891bfa670..9952fd22a1 100644
--- a/src/languages/csharp.js
+++ b/src/languages/csharp.js
@@ -22,6 +22,7 @@ function(hljs) {
     literal:
       'null false true'
   };
+  var TITLE_MODE = hljs.inherit(hljs.TITLE_MODE, {begin: '[a-zA-Z](\\.?\\w)*'});
   var NUMBERS = {
     className: 'number',
     variants: [
@@ -86,6 +87,11 @@ function(hljs) {
     ]
   };
 
+  var GENERIC_MODIFIER = {
+    begin: "<",
+    end: ">",
+    keywords: "in out"
+  };
   var TYPE_IDENT_RE = hljs.IDENT_RE + '(<' + hljs.IDENT_RE + '(\\s*,\\s*' + hljs.IDENT_RE + ')*>)?(\\[\\])?';
 
   return {
@@ -131,7 +137,9 @@ function(hljs) {
         beginKeywords: 'class interface', end: /[{;=]/,
         illegal: /[^\s:,]/,
         contains: [
-          hljs.TITLE_MODE,
+          { beginKeywords: "where class" },
+          TITLE_MODE,
+          GENERIC_MODIFIER,
           hljs.C_LINE_COMMENT_MODE,
           hljs.C_BLOCK_COMMENT_MODE
         ]
@@ -140,7 +148,7 @@ function(hljs) {
         beginKeywords: 'namespace', end: /[{;=]/,
         illegal: /[^\s:]/,
         contains: [
-          hljs.inherit(hljs.TITLE_MODE, {begin: '[a-zA-Z](\\.?\\w)*'}),
+          TITLE_MODE,
           hljs.C_LINE_COMMENT_MODE,
           hljs.C_BLOCK_COMMENT_MODE
         ]
diff --git a/test/markup/csharp/generic_modifiers.expect.txt b/test/markup/csharp/generic_modifiers.expect.txt
new file mode 100644
index 0000000000..bf6d8c3fba
--- /dev/null
+++ b/test/markup/csharp/generic_modifiers.expect.txt
@@ -0,0 +1,7 @@
+<span class="hljs-keyword">interface</span> <span class="hljs-title">IObserver</span>&lt;<span class="hljs-keyword">in</span> T&gt;;
+{}
+
+<span class="hljs-keyword">interface</span> <span class="hljs-title">IObservable</span>&lt;<span class="hljs-keyword">out</span> T&gt;;
+{}
+
+<span class="hljs-keyword">public</span> <span class="hljs-keyword">delegate</span> <span class="hljs-keyword">void</span> DContravariant&lt;<span class="hljs-keyword">in</span> A&gt;(A argument);
diff --git a/test/markup/csharp/generic_modifiers.txt b/test/markup/csharp/generic_modifiers.txt
new file mode 100644
index 0000000000..0af70e5c53
--- /dev/null
+++ b/test/markup/csharp/generic_modifiers.txt
@@ -0,0 +1,7 @@
+interface IObserver<in T>;
+{}
+
+interface IObservable<out T>;
+{}
+
+public delegate void DContravariant<in A>(A argument);
diff --git a/test/markup/csharp/titles.expect.txt b/test/markup/csharp/titles.expect.txt
index 185cb34c2e..be471a6db1 100644
--- a/test/markup/csharp/titles.expect.txt
+++ b/test/markup/csharp/titles.expect.txt
@@ -1,6 +1,6 @@
 <span class="hljs-keyword">namespace</span> <span class="hljs-title">Foo</span> <span class="hljs-comment">// namespace</span>
 {
-    <span class="hljs-keyword">public</span> <span class="hljs-keyword">class</span> <span class="hljs-title">Greet</span> : <span class="hljs-title">Base</span>, <span class="hljs-title">Other</span> <span class="hljs-comment">// class</span>
+    <span class="hljs-keyword">public</span> <span class="hljs-keyword">class</span> <span class="hljs-title">Greet</span> : <span class="hljs-title">Base</span>, <span class="hljs-title">Other</span>, <span class="hljs-title">IInterface.test.path</span> <span class="hljs-comment">// class</span>
     {
         <span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-title">Greet</span>(<span class="hljs-params"><span class="hljs-keyword">string</span> who</span>) <span class="hljs-comment">// function</span></span>
         {
@@ -16,4 +16,6 @@
         }
     }
 
+    <span class="hljs-keyword">public</span> <span class="hljs-keyword">class</span> <span class="hljs-title">TesterA</span>&lt;R, S&gt;  <span class="hljs-keyword">where</span> <span class="hljs-title">R</span> : <span class="hljs-keyword">class</span> <span class="hljs-keyword">where</span> <span class="hljs-title">S</span> : <span class="hljs-title">IComparable</span>
+    {}
 }
diff --git a/test/markup/csharp/titles.txt b/test/markup/csharp/titles.txt
index ee1d81547a..802e305e55 100644
--- a/test/markup/csharp/titles.txt
+++ b/test/markup/csharp/titles.txt
@@ -1,6 +1,6 @@
 namespace Foo // namespace
 {
-    public class Greet : Base, Other // class
+    public class Greet : Base, Other, IInterface.test.path // class
     {
         public Greet(string who) // function
         {
@@ -16,4 +16,6 @@ namespace Foo // namespace
         }
     }
 
+    public class TesterA<R, S>  where R : class where S : IComparable
+    {}
 }