Fortran: fixed support of "dotted" keywords/literals (#4043)

* Fortran: fixed support of "dotted" keywords

This patch adds a pattern to correctly match
keywords delimited by dots (.).
The pattern also follows the following rules from
the format:
- keywords names start with a letter (or dot).
- names should only contain latin characters,
  digits or the underscore symbol.
- identifiers starting with a dot must end with a
  dot.

CHANGES.md

@@ -39,6 +39,7 @@ Core Grammars:
 - enh(markdown) add entity support [David Schach][] [TaraLei][]
 - enh(css) add `justify-items` and `justify-self` attributes [Vasily Polovnyov][]
 - enh(css) add `accent-color`, `appearance`, `color-scheme`, `rotate`, `scale` and `translate` attributes [Carl Räfting][]
+- fix(fortran) fixes parsing of keywords delimited by dots [Julien Bloino][]
 
 New Grammars:
 
@@ -90,6 +91,7 @@ Themes:
 [Rúnar Bjarnason]: https://github.com/runarorama
 [Carl Räfting]: https://github.com/carlrafting
 [BackupMiles]: https://github.com/BackupMiles
+[Julien Bloino]: https://github.com/jbloino
 
 
 

src/languages/fortran.js

@@ -550,6 +550,7 @@ export default function(hljs) {
       'f95'
     ],
     keywords: {
+      $pattern: /\b[a-z][a-z0-9_]+\b|\.[a-z][a-z0-9_]+\./,
       keyword: KEYWORDS,
       literal: LITERALS,
       built_in: BUILT_INS

test/markup/fortran/dot_keywords.expect.txt

@@ -0,0 +1,8 @@
+<span class="hljs-keyword">logical</span> :: A=<span class="hljs-literal">.true.</span>, B=<span class="hljs-literal">.false.</span>, C=<span class="hljs-literal">.true.</span>, D=<span class="hljs-literal">.false.</span>
+<span class="hljs-keyword">logical</span> :: E
+
+E = <span class="hljs-number">3</span> &lt; <span class="hljs-number">4</span> <span class="hljs-keyword">.and.</span> B
+E = <span class="hljs-string">&#x27;ij&#x27;</span> &lt;= <span class="hljs-string">&#x27;ijk&#x27;</span> <span class="hljs-keyword">.and.</span> C
+E = B <span class="hljs-keyword">.or.</span> A <span class="hljs-keyword">.and.</span> D
+E = (B <span class="hljs-keyword">.or.</span> A) <span class="hljs-keyword">.and.</span> C
+E = A <span class="hljs-keyword">.and.</span> <span class="hljs-keyword">.not.</span>B

test/markup/fortran/dot_keywords.txt

@@ -0,0 +1,8 @@
+logical :: A=.true., B=.false., C=.true., D=.false.
+logical :: E
+
+E = 3 < 4 .and. B
+E = 'ij' <= 'ijk' .and. C
+E = B .or. A .and. D
+E = (B .or. A) .and. C
+E = A .and. .not.B