(swift) New string grammar

AUTHORS.txt

@@ -310,3 +310,4 @@ Contributors:
 - Kyle Brown <kylebrown9@github>
 - Marcus Ortiz <[email protected]>
 - Guillaume Grossetie <[email protected]>
+- Steven Van Impe <[email protected]>

CHANGES.md

@@ -7,9 +7,9 @@ New Languages:
 Language improvements:
 
 - enh(makefile): Add `make` as an alias (#2883) [tripleee][]
+- enh(swift) Improved grammar for strings (#2819) [Steven Van Impe][]
 - fix(asciidoc): Handle section titles level 5 (#2868) [Vaibhav Chanana][]
 
-
 Grammar improvements:
 
 - enh(vb) Large rework of VB.net grammar (#2808) [Jan Pilzer][]
@@ -29,6 +29,7 @@ Grammar improvements:
 [Oldes Huhuman]: https://github.com/Oldes
 [Josh Goebel]: https://github.com/joshgoebel
 [tripleee]: https://github.com/tripleee
+[Steven Van Impe]: https://github.com/svanimpe/
 [Vaibhav Chanana]: https://github.com/il3ven
 
 ## Version 10.4.1 (tentative)

src/languages/swift.js

@@ -2,14 +2,16 @@
 Language: Swift
 Description: Swift is a general-purpose programming language built using a modern approach to safety, performance, and software design patterns.
 Author: Chris Eidhof <[email protected]>
-Contributors: Nate Cook <[email protected]>, Alexander Lichter <[email protected]>
+Contributors: Nate Cook <[email protected]>, Alexander Lichter <[email protected]>, Steven Van Impe <[email protected]>
 Website: https://swift.org
 Category: common, system
 */
 
+import { concat } from "../lib/regex.js";
 
+/** @type LanguageFn */
 export default function(hljs) {
-  var SWIFT_KEYWORDS = {
+  const SWIFT_KEYWORDS = {
       // override the pattern since the default of of /\w+/ is not sufficient to
       // capture the keywords that start with the character "#"
       $pattern: /[\w#]+/,
@@ -41,43 +43,29 @@ export default function(hljs) {
         'withUnsafePointer withUnsafePointers withVaList zip'
     };
 
-  var TYPE = {
+  const TYPE = {
     className: 'type',
     begin: '\\b[A-Z][\\w\u00C0-\u02B8\']*',
     relevance: 0
   };
   // slightly more special to swift
-  var OPTIONAL_USING_TYPE = {
+  const OPTIONAL_USING_TYPE = {
     className: 'type',
     begin: '\\b[A-Z][\\w\u00C0-\u02B8\']*[!?]'
   };
-  var BLOCK_COMMENT = hljs.COMMENT(
+  const BLOCK_COMMENT = hljs.COMMENT(
     '/\\*',
     '\\*/',
     {
       contains: ['self']
     }
   );
-  var SUBST = {
-    className: 'subst',
-    begin: /\\\(/, end: '\\)',
-    keywords: SWIFT_KEYWORDS,
-    contains: [] // assigned later
-  };
-  var STRING = {
-    className: 'string',
-    contains: [hljs.BACKSLASH_ESCAPE, SUBST],
-    variants: [
-      {begin: /"""/, end: /"""/},
-      {begin: /"/, end: /"/},
-    ]
-  };
 
   // https://docs.swift.org/swift-book/ReferenceManual/LexicalStructure.html#grammar_numeric-literal
   // TODO: Update for leading `-` after lookbehind is supported everywhere
-  var decimalDigits = '([0-9]_*)+';
-  var hexDigits = '([0-9a-fA-F]_*)+';
-  var NUMBER = {
+  const decimalDigits = '([0-9]_*)+';
+  const hexDigits = '([0-9a-fA-F]_*)+';
+  const NUMBER = {
       className: 'number',
       relevance: 0,
       variants: [
@@ -96,7 +84,53 @@ export default function(hljs) {
         { begin: /\b0b([01]_*)+\b/ },
       ]
   };
-  SUBST.contains = [NUMBER];
+
+  // https://docs.swift.org/swift-book/ReferenceManual/LexicalStructure.html#grammar_string-literal
+  const ESCAPED_CHARACTER = (rawDelimiter = "") => ({
+    className: 'subst',
+    variants: [
+      { begin: concat(/\\/, rawDelimiter, /[0\\tnr"']/) },
+      { begin: concat(/\\/, rawDelimiter, /u\{[0-9a-fA-F]{1,8}\}/) }
+    ]
+  });
+  const ESCAPED_NEWLINE = (rawDelimiter = "") => ({
+    className: 'subst',
+    begin: concat(/\\/, rawDelimiter, /[\t ]*(?:[\r\n]|\r\n)/)
+  });
+  const INTERPOLATION = (rawDelimiter = "") => ({
+    className: 'subst',
+    label: "interpol",
+    begin: concat(/\\/, rawDelimiter, /\(/),
+    end: /\)/
+  });
+  const MULTILINE_STRING = (rawDelimiter = "") => ({
+    begin: concat(rawDelimiter, /"""/),
+    end: concat(/"""/, rawDelimiter),
+    contains: [ESCAPED_CHARACTER(rawDelimiter), ESCAPED_NEWLINE(rawDelimiter), INTERPOLATION(rawDelimiter)]
+  });
+  const SINGLE_LINE_STRING = (rawDelimiter = "") => ({
+    begin: concat(rawDelimiter, /"/),
+    end: concat(/"/, rawDelimiter),
+    contains: [ESCAPED_CHARACTER(rawDelimiter), INTERPOLATION(rawDelimiter)]
+  });
+  const STRING = {
+    className: 'string',
+    variants: [
+      MULTILINE_STRING(),
+      MULTILINE_STRING("#"),
+      MULTILINE_STRING("##"),
+      MULTILINE_STRING("###"),
+      SINGLE_LINE_STRING(),
+      SINGLE_LINE_STRING("#"),
+      SINGLE_LINE_STRING("##"),
+      SINGLE_LINE_STRING("###"),
+    ]
+  };
+  for (const variant of STRING.variants) {
+    const interpolation = variant.contains.find(mode => mode.label === "interpol");
+    // TODO: Interpolation can contain any expression, so there's room for improvement here.
+    interpolation.contains = [STRING, NUMBER];
+  }
 
   return {
     name: 'Swift',

test/markup/swift/strings.expect.txt

@@ -0,0 +1,72 @@
+<span class="hljs-string">&quot;escaped characters <span class="hljs-subst">\0</span><span class="hljs-subst">\\</span><span class="hljs-subst">\t</span><span class="hljs-subst">\n</span><span class="hljs-subst">\r</span><span class="hljs-subst">\&quot;</span><span class="hljs-subst">\&#x27;</span>&quot;</span>
+<span class="hljs-string">&quot;escaped unicode <span class="hljs-subst">\u{0}</span><span class="hljs-subst">\u{12}</span><span class="hljs-subst">\u{345}</span><span class="hljs-subst">\u{6789}</span><span class="hljs-subst">\u{abcde}</span><span class="hljs-subst">\u{fABCDE}</span><span class="hljs-subst">\u{F012345}</span><span class="hljs-subst">\u{67890abc}</span>&quot;</span>
+<span class="hljs-string">#&quot;escaped characters <span class="hljs-subst">\#0</span><span class="hljs-subst">\#\</span><span class="hljs-subst">\#t</span><span class="hljs-subst">\#n</span><span class="hljs-subst">\#r</span><span class="hljs-subst">\#&quot;</span><span class="hljs-subst">\#&#x27;</span>&quot;#</span>
+<span class="hljs-string">#&quot;escaped unicode <span class="hljs-subst">\#u{0}</span><span class="hljs-subst">\#u{12}</span><span class="hljs-subst">\#u{345}</span><span class="hljs-subst">\#u{6789}</span><span class="hljs-subst">\#u{abcde}</span><span class="hljs-subst">\#u{fABCDE}</span><span class="hljs-subst">\#u{F012345}</span><span class="hljs-subst">\#u{67890abc}</span>&quot;#</span>
+<span class="hljs-string">#&quot;raw characters \0\\\t\n\r\&quot;\&#x27;\u{6789}&quot;#</span>
+<span class="hljs-string">##&quot;escaped characters <span class="hljs-subst">\##0</span><span class="hljs-subst">\##\</span><span class="hljs-subst">\##t</span><span class="hljs-subst">\##n</span><span class="hljs-subst">\##r</span><span class="hljs-subst">\##&quot;</span><span class="hljs-subst">\##&#x27;</span>&quot;##</span>
+<span class="hljs-string">##&quot;escaped unicode <span class="hljs-subst">\##u{0}</span><span class="hljs-subst">\##u{12}</span><span class="hljs-subst">\##u{345}</span><span class="hljs-subst">\##u{6789}</span><span class="hljs-subst">\##u{abcde}</span><span class="hljs-subst">\##u{fABCDE}</span><span class="hljs-subst">\##u{F012345}</span><span class="hljs-subst">\##u{67890abc}</span>&quot;##</span>
+<span class="hljs-string">##&quot;raw characters \0\\\t\n\r\&quot;\&#x27;\u{6789} \#0\#\\#t\#n\#r\#&quot;\#&#x27;\#u{6789}&quot;##</span>
+<span class="hljs-string">###&quot;escaped characters <span class="hljs-subst">\###0</span><span class="hljs-subst">\###\</span><span class="hljs-subst">\###t</span><span class="hljs-subst">\###n</span><span class="hljs-subst">\###r</span><span class="hljs-subst">\###&quot;</span><span class="hljs-subst">\###&#x27;</span>&quot;###</span>
+<span class="hljs-string">###&quot;escaped unicode <span class="hljs-subst">\###u{0}</span><span class="hljs-subst">\###u{12}</span><span class="hljs-subst">\###u{345}</span><span class="hljs-subst">\###u{6789}</span><span class="hljs-subst">\###u{abcde}</span><span class="hljs-subst">\###u{fABCDE}</span><span class="hljs-subst">\###u{F012345}</span><span class="hljs-subst">\###u{67890abc}</span>&quot;###</span>
+<span class="hljs-string">###&quot;raw characters \0\\\t\n\r\&quot;\&#x27;\u{6789} \#0\#\\#t\#n\#r\#&quot;\#&#x27;\#u{6789} \##0\##\\##t\##n\##r\##&quot;\##&#x27;\##u{6789}&quot;###</span>
+
+<span class="hljs-string">&quot;&quot;&quot;
+escaped characters <span class="hljs-subst">\0</span><span class="hljs-subst">\\</span><span class="hljs-subst">\t</span><span class="hljs-subst">\n</span><span class="hljs-subst">\r</span><span class="hljs-subst">\&quot;</span><span class="hljs-subst">\&#x27;</span>
+escaped unicode <span class="hljs-subst">\u{0}</span><span class="hljs-subst">\u{12}</span><span class="hljs-subst">\u{345}</span><span class="hljs-subst">\u{6789}</span><span class="hljs-subst">\u{abcde}</span><span class="hljs-subst">\u{fABCDE}</span><span class="hljs-subst">\u{F012345}</span><span class="hljs-subst">\u{67890abc}</span>
+&quot;&quot;&quot;</span>
+<span class="hljs-string">#&quot;&quot;&quot;
+escaped characters <span class="hljs-subst">\#0</span><span class="hljs-subst">\#\</span><span class="hljs-subst">\#t</span><span class="hljs-subst">\#n</span><span class="hljs-subst">\#r</span><span class="hljs-subst">\#&quot;</span><span class="hljs-subst">\#&#x27;</span>
+escaped unicode <span class="hljs-subst">\#u{0}</span><span class="hljs-subst">\#u{12}</span><span class="hljs-subst">\#u{345}</span><span class="hljs-subst">\#u{6789}</span><span class="hljs-subst">\#u{abcde}</span><span class="hljs-subst">\#u{fABCDE}</span><span class="hljs-subst">\#u{F012345}</span><span class="hljs-subst">\#u{67890abc}</span>
+raw characters \0\\\t\n\r\&quot;\&#x27;\u{6789}
+&quot;&quot;&quot;#</span>
+<span class="hljs-string">##&quot;&quot;&quot;
+escaped characters <span class="hljs-subst">\##0</span><span class="hljs-subst">\##\</span><span class="hljs-subst">\##t</span><span class="hljs-subst">\##n</span><span class="hljs-subst">\##r</span><span class="hljs-subst">\##&quot;</span><span class="hljs-subst">\##&#x27;</span>
+escaped unicode <span class="hljs-subst">\##u{0}</span><span class="hljs-subst">\##u{12}</span><span class="hljs-subst">\##u{345}</span><span class="hljs-subst">\##u{6789}</span><span class="hljs-subst">\##u{abcde}</span><span class="hljs-subst">\##u{fABCDE}</span><span class="hljs-subst">\##u{F012345}</span><span class="hljs-subst">\##u{67890abc}</span>
+raw characters \0\\\t\n\r\&quot;\&#x27;\u{6789} \#0\#\\#t\#n\#r\#&quot;\#&#x27;\#u{6789}
+&quot;&quot;&quot;##</span>
+<span class="hljs-string">###&quot;&quot;&quot;
+escaped characters <span class="hljs-subst">\###0</span><span class="hljs-subst">\###\</span><span class="hljs-subst">\###t</span><span class="hljs-subst">\###n</span><span class="hljs-subst">\###r</span><span class="hljs-subst">\###&quot;</span><span class="hljs-subst">\###&#x27;</span>
+escaped unicode <span class="hljs-subst">\###u{0}</span><span class="hljs-subst">\###u{12}</span><span class="hljs-subst">\###u{345}</span><span class="hljs-subst">\###u{6789}</span><span class="hljs-subst">\###u{abcde}</span><span class="hljs-subst">\###u{fABCDE}</span><span class="hljs-subst">\###u{F012345}</span><span class="hljs-subst">\###u{67890abc}</span>
+raw characters \0\\\t\n\r\&quot;\&#x27;\u{6789} \#0\#\\#t\#n\#r\#&quot;\#&#x27;\#u{6789} \##0\##\\##t\##n\##r\##&quot;\##&#x27;\##u{6789}
+&quot;&quot;&quot;###</span>
+
+<span class="hljs-string">&quot;&quot;&quot;
+escaped newline <span class="hljs-subst">\   
+</span>same line
+&quot;&quot;&quot;</span>
+<span class="hljs-string">#&quot;&quot;&quot;
+escaped newline <span class="hljs-subst">\#   
+</span>same line
+&quot;&quot;&quot;#</span>
+<span class="hljs-string">##&quot;&quot;&quot;
+escaped newline <span class="hljs-subst">\##   
+</span>same line
+&quot;&quot;&quot;##</span>
+<span class="hljs-string">###&quot;&quot;&quot;
+escaped newline <span class="hljs-subst">\###   
+</span>same line
+&quot;&quot;&quot;###</span>
+
+<span class="hljs-string">&quot;interpolation <span class="hljs-subst">\(x)</span>&quot;</span>
+<span class="hljs-string">#&quot;interpolation <span class="hljs-subst">\#(<span class="hljs-number">123</span>)</span> raw \(123)&quot;#</span>
+<span class="hljs-string">##&quot;interpolation <span class="hljs-subst">\##(<span class="hljs-number">1.23</span>)</span> raw \#(1.23) raw \(1.23)&quot;##</span>
+<span class="hljs-string">###&quot;interpolation <span class="hljs-subst">\###(<span class="hljs-string">&quot;string&quot;</span>)</span> raw \##(&quot;string&quot;) raw \#(&quot;string&quot;) raw \(&quot;string&quot;)&quot;###</span>
+
+<span class="hljs-string">&quot;&quot;&quot;
+interpolation <span class="hljs-subst">\(x)</span>
+&quot;&quot;&quot;</span>
+<span class="hljs-string">#&quot;&quot;&quot;
+interpolation <span class="hljs-subst">\#(<span class="hljs-number">123</span>)</span>
+raw \(123)
+&quot;&quot;&quot;#</span>
+<span class="hljs-string">##&quot;&quot;&quot;
+interpolation <span class="hljs-subst">\##(<span class="hljs-number">1.23</span>)</span>
+raw \#(1.23)
+raw \(1.23)
+&quot;&quot;&quot;##</span>
+<span class="hljs-string">###&quot;&quot;&quot;
+interpolation <span class="hljs-subst">\###(<span class="hljs-string">&quot;string&quot;</span>)</span>
+raw \##(&quot;string&quot;)
+raw \#(&quot;string&quot;)
+raw \(&quot;string&quot;)
+&quot;&quot;&quot;###</span>

test/markup/swift/strings.txt

@@ -0,0 +1,72 @@
+"escaped characters \0\\\t\n\r\"\'"
+"escaped unicode \u{0}\u{12}\u{345}\u{6789}\u{abcde}\u{fABCDE}\u{F012345}\u{67890abc}"
+#"escaped characters \#0\#\\#t\#n\#r\#"\#'"#
+#"escaped unicode \#u{0}\#u{12}\#u{345}\#u{6789}\#u{abcde}\#u{fABCDE}\#u{F012345}\#u{67890abc}"#
+#"raw characters \0\\\t\n\r\"\'\u{6789}"#
+##"escaped characters \##0\##\\##t\##n\##r\##"\##'"##
+##"escaped unicode \##u{0}\##u{12}\##u{345}\##u{6789}\##u{abcde}\##u{fABCDE}\##u{F012345}\##u{67890abc}"##
+##"raw characters \0\\\t\n\r\"\'\u{6789} \#0\#\\#t\#n\#r\#"\#'\#u{6789}"##
+###"escaped characters \###0\###\\###t\###n\###r\###"\###'"###
+###"escaped unicode \###u{0}\###u{12}\###u{345}\###u{6789}\###u{abcde}\###u{fABCDE}\###u{F012345}\###u{67890abc}"###
+###"raw characters \0\\\t\n\r\"\'\u{6789} \#0\#\\#t\#n\#r\#"\#'\#u{6789} \##0\##\\##t\##n\##r\##"\##'\##u{6789}"###
+
+"""
+escaped characters \0\\\t\n\r\"\'
+escaped unicode \u{0}\u{12}\u{345}\u{6789}\u{abcde}\u{fABCDE}\u{F012345}\u{67890abc}
+"""
+#"""
+escaped characters \#0\#\\#t\#n\#r\#"\#'
+escaped unicode \#u{0}\#u{12}\#u{345}\#u{6789}\#u{abcde}\#u{fABCDE}\#u{F012345}\#u{67890abc}
+raw characters \0\\\t\n\r\"\'\u{6789}
+"""#
+##"""
+escaped characters \##0\##\\##t\##n\##r\##"\##'
+escaped unicode \##u{0}\##u{12}\##u{345}\##u{6789}\##u{abcde}\##u{fABCDE}\##u{F012345}\##u{67890abc}
+raw characters \0\\\t\n\r\"\'\u{6789} \#0\#\\#t\#n\#r\#"\#'\#u{6789}
+"""##
+###"""
+escaped characters \###0\###\\###t\###n\###r\###"\###'
+escaped unicode \###u{0}\###u{12}\###u{345}\###u{6789}\###u{abcde}\###u{fABCDE}\###u{F012345}\###u{67890abc}
+raw characters \0\\\t\n\r\"\'\u{6789} \#0\#\\#t\#n\#r\#"\#'\#u{6789} \##0\##\\##t\##n\##r\##"\##'\##u{6789}
+"""###
+
+"""
+escaped newline \   
+same line
+"""
+#"""
+escaped newline \#   
+same line
+"""#
+##"""
+escaped newline \##   
+same line
+"""##
+###"""
+escaped newline \###   
+same line
+"""###
+
+"interpolation \(x)"
+#"interpolation \#(123) raw \(123)"#
+##"interpolation \##(1.23) raw \#(1.23) raw \(1.23)"##
+###"interpolation \###("string") raw \##("string") raw \#("string") raw \("string")"###
+
+"""
+interpolation \(x)
+"""
+#"""
+interpolation \#(123)
+raw \(123)
+"""#
+##"""
+interpolation \##(1.23)
+raw \#(1.23)
+raw \(1.23)
+"""##
+###"""
+interpolation \###("string")
+raw \##("string")
+raw \#("string")
+raw \("string")
+"""###