enh(php) highlight variables (#2785)

Resolves #2778.

* Also modernize a bit.

CHANGES.md

@@ -5,6 +5,7 @@ Language Improvements:
 - enh(julia) Update keyword lists for Julia 1.x (#2781) [Fredrik Ekre][]
 - enh(python) Match numeric literals per the language reference [Richard Gibson][]
 - enh(ruby) Match numeric literals per language documentation [Richard Gibson][]
+- enh(php) highlight variables (#2785) [Taufik Nurrohman][]
 
 Dev Improvements:
 
@@ -13,6 +14,7 @@ Dev Improvements:
 [Fredrik Ekre]: https://github.com/fredrikekre
 [Richard Gibson]: https://github.com/gibson042
 [Josh Goebel]: https://github.com/joshgoebel
+[Taufik Nurrohman]: https://github.com/taufik-nurrohman
 
 
 ## Version 10.3.1
@@ -1323,7 +1325,7 @@ Notable fixes and improvements to existing languages:
 - HTML `<script>` tag now allows any language, not just JavaScript.
 - Multi-line comments are supported now in MatLab.
 
-[Taufik Nurrohman]: https://github.com/tovic
+[Taufik Nurrohman]: https://github.com/taufik-nurrohman
 [Jet Brains]: https://www.jetbrains.com/
 [Peter Piwowarski]: https://github.com/oldlaptop
 [Kenta Sato]: https://github.com/bicycle1885

src/languages/php.js

@@ -11,37 +11,38 @@ Category: common
  * @returns {LanguageDetail}
  * */
 export default function(hljs) {
-  var VARIABLE = {
+  const VARIABLE = {
+    className: 'variable',
     begin: '\\$+[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*'
   };
-  var PREPROCESSOR = {
+  const PREPROCESSOR = {
     className: 'meta',
     variants: [
       { begin: /<\?php/, relevance: 10 }, // boost for obvious PHP
       { begin: /<\?[=]?/ },
       { begin: /\?>/ } // end php tag
     ]
   };
-  var SUBST = {
+  const SUBST = {
     className: 'subst',
     variants: [
       { begin: /\$\w+/ },
       { begin: /\{\$/, end: /\}/ }
     ]
   };
-  var SINGLE_QUOTED = hljs.inherit(hljs.APOS_STRING_MODE, {
+  const SINGLE_QUOTED = hljs.inherit(hljs.APOS_STRING_MODE, {
     illegal: null,
   });
-  var DOUBLE_QUOTED = hljs.inherit(hljs.QUOTE_STRING_MODE, {
+  const DOUBLE_QUOTED = hljs.inherit(hljs.QUOTE_STRING_MODE, {
     illegal: null,
     contains: hljs.QUOTE_STRING_MODE.contains.concat(SUBST),
   });
-  var HEREDOC = hljs.END_SAME_AS_BEGIN({
+  const HEREDOC = hljs.END_SAME_AS_BEGIN({
     begin: /<<<[ \t]*(\w+)\n/,
     end: /[ \t]*(\w+)\b/,
     contains: hljs.QUOTE_STRING_MODE.contains.concat(SUBST),
   });
-  var STRING = {
+  const STRING = {
     className: 'string',
     contains: [hljs.BACKSLASH_ESCAPE, PREPROCESSOR],
     variants: [
@@ -56,8 +57,8 @@ export default function(hljs) {
       HEREDOC
     ]
   };
-  var NUMBER = {variants: [hljs.BINARY_NUMBER_MODE, hljs.C_NUMBER_MODE]};
-  var KEYWORDS = {
+  const NUMBER = {variants: [hljs.BINARY_NUMBER_MODE, hljs.C_NUMBER_MODE]};
+  const KEYWORDS = {
     keyword:
     // Magic constants:
     // <https://www.php.net/manual/en/language.constants.predefined.php>

test/markup/php/comments.expect.txt

@@ -4,8 +4,8 @@
  * <span class="hljs-doctag">@param</span> int $a
  * <span class="hljs-doctag">@return</span> bool
  */</span>
-<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">isEven</span>(<span class="hljs-params">$a</span>) </span>{
-    <span class="hljs-keyword">return</span> ($a % <span class="hljs-number">2</span>) === <span class="hljs-number">0</span>;
+<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">isEven</span>(<span class="hljs-params"><span class="hljs-variable">$a</span></span>) </span>{
+    <span class="hljs-keyword">return</span> (<span class="hljs-variable">$a</span> % <span class="hljs-number">2</span>) === <span class="hljs-number">0</span>;
 }
 
 <span class="hljs-comment">/**
@@ -14,6 +14,6 @@
  * <span class="hljs-doctag">@param</span> int $a
  * <span class="hljs-doctag">@return</span> bool
  */</span>
-<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">isOdd</span>(<span class="hljs-params">$a</span>) </span>{
-    <span class="hljs-keyword">return</span> ($a % <span class="hljs-number">2</span>) === <span class="hljs-number">1</span>;
+<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">isOdd</span>(<span class="hljs-params"><span class="hljs-variable">$a</span></span>) </span>{
+    <span class="hljs-keyword">return</span> (<span class="hljs-variable">$a</span> % <span class="hljs-number">2</span>) === <span class="hljs-number">1</span>;
 }