enh(swift) add parameter pack keywords (#3803)

* Support parameter pack

* Update changes

* Merge and improve test case

* Use scope

* Use keywords in GENERIC_PARAMETERS

CHANGES.md

@@ -12,6 +12,7 @@ Core Grammars:
 - fix(haxe) differentiate `abstract` declaration from keyword [Robert Borghese][]
 - fix(bash) do not delimit a string by an escaped apostrophe [hancar][]
 - enh(swift) support `macro` keyword [Bradley Mackey][]
+- enh(swift) support parameter pack keywords [Bradley Mackey][]
 
 Dev tool: 
 
@@ -24,6 +25,7 @@ Dev tool:
 [Checconio]: https://github.com/Checconio
 [Bradley Mackey]: https://github.com/bradleymackey
 
+
 ## Version 11.8.0
 
 Parser engine:

src/languages/lib/kws_swift.js

@@ -53,6 +53,7 @@ export const keywords = [
   'distributed',
   'do',
   'dynamic', // contextual
+  'each',
   'else',
   'enum',
   'extension',

src/languages/swift.js

@@ -300,6 +300,7 @@ export default function(hljs) {
   const GENERIC_PARAMETERS = {
     begin: /</,
     end: />/,
+    keywords: 'repeat each',
     contains: [
       ...COMMENTS,
       TYPE

test/markup/swift/parameterpack.expect.txt

@@ -0,0 +1,7 @@
+<span class="hljs-keyword">func</span> <span class="hljs-title function_">expand</span>&lt;<span class="hljs-keyword">each</span> <span class="hljs-type">T</span>, <span class="hljs-keyword">repeat</span> <span class="hljs-keyword">each</span> <span class="hljs-type">U</span>&gt;(<span class="hljs-params">value</span>: (<span class="hljs-keyword">repeat</span> <span class="hljs-keyword">each</span> <span class="hljs-type">T</span>), <span class="hljs-params">other</span>: <span class="hljs-keyword">each</span> <span class="hljs-type">U</span>, <span class="hljs-params">another</span>: <span class="hljs-keyword">repeat</span> <span class="hljs-keyword">each</span> <span class="hljs-type">T</span>) -&gt; (<span class="hljs-keyword">repeat</span> (<span class="hljs-keyword">each</span> <span class="hljs-type">T</span>)<span class="hljs-operator">?</span>) {
+  <span class="hljs-keyword">return</span> (<span class="hljs-keyword">repeat</span> <span class="hljs-keyword">each</span> value, <span class="hljs-keyword">each</span> value)
+}
+
+<span class="hljs-keyword">let</span> x: (<span class="hljs-keyword">repeat</span> <span class="hljs-keyword">each</span> <span class="hljs-type">T</span>) -&gt; <span class="hljs-type">Bool</span> <span class="hljs-operator">=</span> { }
+
+(<span class="hljs-keyword">each</span> <span class="hljs-type">U</span>, <span class="hljs-keyword">repeat</span> <span class="hljs-keyword">each</span> <span class="hljs-type">T</span>)

test/markup/swift/parameterpack.txt

@@ -0,0 +1,7 @@
+func expand<each T, repeat each U>(value: (repeat each T), other: each U, another: repeat each T) -> (repeat (each T)?) {
+  return (repeat each value, each value)
+}
+
+let x: (repeat each T) -> Bool = { }
+
+(each U, repeat each T)