Highlight shortened lists for syzlang DSL (rouge-ruby#1808)

Update the lexer for syzlang DSL to allow processing inputs with lists and
syscall arguments replaced with "...". This is useful for highlighting snippets
that are shortened for readability.

Also add tests for the new behavior.

Signed-off-by: Andrey Konovalov <[email protected]>

lib/rouge/lexers/syzlang.rb

@@ -148,6 +148,7 @@ def self.keywords_type
 
       state :flags_list do
         rule inline_spaces, Text
+        rule %r/\./, Punctuation
         mixin :mixin_name
         mixin :mixin_number
         mixin :mixin_string
@@ -158,6 +159,7 @@ def self.keywords_type
       state :syscall_args do
         rule spaces, Text
         rule comment, Comment
+        rule %r/\./, Punctuation
         rule id do
           token Name
           push :arg_type

spec/lexers/syzlang_spec.rb

@@ -301,6 +301,31 @@
         ['Keyword.Type', 'int16']
     end
 
+    # The tests below check that the lexer can process inputs with lists and
+    # syscall arguments replaced with "...". This is useful for highlighting
+    # syzlang snippets that are shortened for readability.
+
+    it 'recognizes shortened flags lists' do
+      assert_tokens_equal "flags = FLAG1, FLAG2, ...",
+        ['Name', 'flags'],
+        ['Text', ' '],
+        ['Punctuation', '='],
+        ['Text', ' '],
+        ['Name', 'FLAG1'],
+        ['Punctuation', ','],
+        ['Text', ' '],
+        ['Name', 'FLAG2'],
+        ['Punctuation', ','],
+        ['Text', ' '],
+        ['Punctuation', '...']
+    end
+
+    it 'recognizes shortened syscalls' do
+      assert_tokens_equal 'foo(...)',
+        ['Name.Function', 'foo'],
+        ['Punctuation', '(...)']
+    end
+
     # The tests below check that the lexer can process inputs with relaxed
     # whitespace usage and after-line comments. This is useful for highlighting
     # syzlang snippets that are split into multiple lines for readability and