Merge pull request #297 from dotnet/dev/jorobich/support-e-escape-sequence

Add support for \e escape sequences in c# strings and characters

Author: JoeRobich

grammars/csharp.tmLanguage

@@ -6156,7 +6156,7 @@
         <key>name</key>
         <string>constant.character.escape.cs</string>
         <key>match</key>
-        <string>\\(['"\\0abfnrtv]|x[0-9a-fA-F]{1,4}|u[0-9a-fA-F]{4})</string>
+        <string>\\(x[0-9a-fA-F]{1,4}|u[0-9a-fA-F]{4}|.)</string>
       </dict>
       <key>string-literal</key>
       <dict>
@@ -6200,7 +6200,7 @@
         <key>name</key>
         <string>constant.character.escape.cs</string>
         <key>match</key>
-        <string>\\(['"\\0abfnrtv]|x[0-9a-fA-F]{1,4}|U[0-9a-fA-F]{8}|u[0-9a-fA-F]{4})</string>
+        <string>\\(x[0-9a-fA-F]{1,4}|U[0-9a-fA-F]{8}|u[0-9a-fA-F]{4}|.)</string>
       </dict>
       <key>verbatim-string-literal</key>
       <dict>

grammars/csharp.tmLanguage.cson

@@ -3705,7 +3705,7 @@ repository:
     ]
   "char-character-escape":
     name: "constant.character.escape.cs"
-    match: "\\\\(['\"\\\\0abfnrtv]|x[0-9a-fA-F]{1,4}|u[0-9a-fA-F]{4})"
+    match: "\\\\(x[0-9a-fA-F]{1,4}|u[0-9a-fA-F]{4}|.)"
   "string-literal":
     name: "string.quoted.double.cs"
     begin: "(?<!@)\""
@@ -3725,7 +3725,7 @@ repository:
     ]
   "string-character-escape":
     name: "constant.character.escape.cs"
-    match: "\\\\(['\"\\\\0abfnrtv]|x[0-9a-fA-F]{1,4}|U[0-9a-fA-F]{8}|u[0-9a-fA-F]{4})"
+    match: "\\\\(x[0-9a-fA-F]{1,4}|U[0-9a-fA-F]{8}|u[0-9a-fA-F]{4}|.)"
   "verbatim-string-literal":
     name: "string.quoted.double.cs"
     begin: "@\""

src/csharp.tmLanguage.yml

@@ -2314,7 +2314,7 @@ repository:
 
   char-character-escape:
     name: constant.character.escape.cs
-    match: \\(['"\\0abfnrtv]|x[0-9a-fA-F]{1,4}|u[0-9a-fA-F]{4})
+    match: \\(x[0-9a-fA-F]{1,4}|u[0-9a-fA-F]{4}|.)
 
   string-literal:
     name: string.quoted.double.cs
@@ -2330,7 +2330,7 @@ repository:
 
   string-character-escape:
     name: constant.character.escape.cs
-    match: \\(['"\\0abfnrtv]|x[0-9a-fA-F]{1,4}|U[0-9a-fA-F]{8}|u[0-9a-fA-F]{4})
+    match: \\(x[0-9a-fA-F]{1,4}|U[0-9a-fA-F]{8}|u[0-9a-fA-F]{4}|.)
 
   verbatim-string-literal:
     name: string.quoted.double.cs

test/literals.tests.ts

@@ -78,6 +78,20 @@ describe("Literals", () => {
                     Token.Punctuation.Semicolon]);
             });
 
+            it("escaped character escape \\e", async () => {
+                const input = Input.InClass(`char x = '\\e';`);
+                const tokens = await tokenize(input);
+
+                tokens.should.deep.equal([
+                    Token.PrimitiveType.Char,
+                    Token.Identifier.FieldName("x"),
+                    Token.Operator.Assignment,
+                    Token.Punctuation.Char.Begin,
+                    Token.Literal.CharacterEscape("\\e"),
+                    Token.Punctuation.Char.End,
+                    Token.Punctuation.Semicolon]);
+            });
+
             it("escaped character escape \\t", async () => {
                 const input = Input.InClass(`char x = '\\t';`);
                 const tokens = await tokenize(input);
@@ -712,6 +726,22 @@ describe("Literals", () => {
                     Token.Punctuation.Semicolon]);
             });
 
+            it("escaped character escape \\e", async () => {
+                const input = Input.InClass(`string test = "hello\\eworld!";`);
+                const tokens = await tokenize(input);
+
+                tokens.should.deep.equal([
+                    Token.PrimitiveType.String,
+                    Token.Identifier.FieldName("test"),
+                    Token.Operator.Assignment,
+                    Token.Punctuation.String.Begin,
+                    Token.Literal.String("hello"),
+                    Token.Literal.CharacterEscape("\\e"),
+                    Token.Literal.String("world!"),
+                    Token.Punctuation.String.End,
+                    Token.Punctuation.Semicolon]);
+            });
+
             it("escaped character escape \\n", async () => {
                 const input = Input.InClass(`string test = "hello\\nworld!";`);
                 const tokens = await tokenize(input);