enh(erlang) add support for underscore separators in numeric literals (#2554)

* (erlang) add support for underscore separators in numeric literals
* (erlang) add tests

Author: seriyps

CHANGES.md

@@ -34,6 +34,7 @@ Language Improvements:
 - fix(yaml) Fix tags to include non-word characters (#2486) [Peter Plantinga][]
 - fix(swift) `@objcMembers` was being partially highlighted (#2543) [Nick Randall][]
 - enh(dart) Add `late` and `required` keywords, and `Never` built-in type (#2550) [Sam Rawlins][]
+- enh(erlang) Add underscore separators to numeric literals (#2554) [Sergey Prokhorov][]
 
 [Josh Goebel]: https://github.com/yyyc514
 [Peter Plantinga]: https://github.com/pplantinga
@@ -42,6 +43,7 @@ Language Improvements:
 [Hankun Lin]: https://github.com/Linhk1606
 [Nick Randall]: https://github.com/nicked
 [Sam Rawlins]: https://github.com/srawlins
+[Sergey Prokhorov]: https://github.com/seriyps
 
 
 ## Version 10.0.2

src/languages/erlang-repl.js

@@ -23,7 +23,7 @@ export default function(hljs) {
       hljs.COMMENT('%', '$'),
       {
         className: 'number',
-        begin: '\\b(\\d+#[a-fA-F0-9]+|\\d+(\\.\\d+)?([eE][-+]?\\d+)?)',
+        begin: '\\b(\\d+(_\\d+)*#[a-fA-F0-9]+(_[a-fA-F0-9]+)*|\\d+(_\\d+)*(\\.\\d+(_\\d+)*)?([eE][-+]?\\d+)?)',
         relevance: 0
       },
       hljs.APOS_STRING_MODE,

src/languages/erlang.js

@@ -20,7 +20,7 @@ export default function(hljs) {
   var COMMENT = hljs.COMMENT('%', '$');
   var NUMBER = {
     className: 'number',
-    begin: '\\b(\\d+#[a-fA-F0-9]+|\\d+(\\.\\d+)?([eE][-+]?\\d+)?)',
+    begin: '\\b(\\d+(_\\d+)*#[a-fA-F0-9]+(_[a-fA-F0-9]+)*|\\d+(_\\d+)*(\\.\\d+(_\\d+)*)?([eE][-+]?\\d+)?)',
     relevance: 0
   };
   var NAMED_FUN = {

test/markup/erlang/numbers.expect.txt

@@ -0,0 +1,14 @@
+Integer = <span class="hljs-number">1234</span>
+BigInteger = <span class="hljs-number">1_234_000</span>
+NegInteger = -<span class="hljs-number">20_000</span>
+Float = <span class="hljs-number">2.34</span>
+BigFloat = <span class="hljs-number">3_333.14159_26535_89793</span>
+SciFloat = <span class="hljs-number">2.4e23</span>
+PlusSciFloat = <span class="hljs-number">2.4e+23</span>
+SmallSciFloat = <span class="hljs-number">2.4e-23</span>
+Binary = <span class="hljs-number">2#1010</span>
+StrangeBinary = <span class="hljs-number">2#1010_1010_1010</span>
+Octal = <span class="hljs-number">8#777</span>
+StrangeOctal = <span class="hljs-number">8#777_666_555</span>
+Hex = <span class="hljs-number">16#1ABEF</span>
+StrangeHex = <span class="hljs-number">16#1234_FACE_987D</span>

test/markup/erlang/numbers.txt

@@ -0,0 +1,14 @@
+Integer = 1234
+BigInteger = 1_234_000
+NegInteger = -20_000
+Float = 2.34
+BigFloat = 3_333.14159_26535_89793
+SciFloat = 2.4e23
+PlusSciFloat = 2.4e+23
+SmallSciFloat = 2.4e-23
+Binary = 2#1010
+StrangeBinary = 2#1010_1010_1010
+Octal = 8#777
+StrangeOctal = 8#777_666_555
+Hex = 16#1ABEF
+StrangeHex = 16#1234_FACE_987D