Added an ANTLR v4 highlighter

README.md

@@ -52,6 +52,7 @@ Smalltalk, OCaml, etc. without a language extension.
 
 Other languages are supported via extensions:
 
+[ANTLR 4](src/lang-antlr4.js);
 [Apollo](src/lang-apollo.js);
 [Basic](src/lang-basic.js);
 [Clojure](src/lang-clj.js);

src/lang-antlr4.js

@@ -0,0 +1,59 @@
+/**
+ * @license
+ * Copyright (C) 2016 Bart Kiers
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * @fileoverview
+ * Registers a language handler for ANTLR 4. <http://www.antlr.org>
+ *
+ * To use, include prettify.js and this file in your HTML page.
+ * Then enclose your code in an HTML tag like so:
+ *      <pre class="prettyprint lang-antlr4">[your ANTLR grammar]</pre>
+ *
+ * Note that embedded code blocks, like `@members::` blocks, are not
+ * highlighted. These blocks can contain arbitrary target code, containing
+ * a large amount of nested curly braces: impossible to define with a (JS)
+ * regex.
+ *
+ * @author Bart Kiers
+ */
+PR['registerLangHandler'](
+    PR['createSimpleLexer']([], [
+
+        [PR['PR_PLAIN'],      /^[\t\n\r \xA0]+/],
+
+        // Comments
+        [PR['PR_COMMENT'],    /^\/\/[^\r\n]*/],
+        [PR['PR_COMMENT'],    /^\/\*[\s\S]*?(?:\*\/|$)/],
+
+        // Literal tokens: single quoted strings and character sets
+        [PR['PR_STRING'],     /^'(?:\\.|[^\\'\r\n])+'/],
+        [PR['PR_STRING'],     /^\[(?:\\.|[^\\\[\]])+]/],
+
+        // Keywords: https://github.com/antlr/grammars-v4/blob/master/antlr4/ANTLRv4Lexer.g4
+        [PR['PR_KEYWORD'],    /^(?:options|tokens|import|fragment|lexer|parser|grammar\s+\w+|protected|public|private|returns|locals|throws|catch|finally|mode)\b/],
+
+        // Predicates
+        [PR['PR_SOURCE'],     /^\{.*?}\?/],
+
+        // Lexer- and parser-rules
+        [PR['PR_TYPE'],       /^[A-Z]\w*/],
+        [PR['PR_LITERAL'],    /^[a-z]\w*/],
+
+        // Fall through rule matching any char as a 'plain' char
+        [PR['PR_PLAIN'], /./]
+    ]),
+    ['antlr4']);