Fix comment highlight in TCL lexer (#2041)

lib/rouge/lexers/tcl.rb

@@ -57,9 +57,9 @@ def self.detect?(text)
 
       def self.gen_command_state(name='')
         state(:"command#{name}") do
-          mixin :word
+          rule %r/#/, Comment, :comment
 
-          rule %r/##{NOT_CHARS[END_LINE]}+/, Comment::Single
+          mixin :word
 
           rule %r/(?=#{CHARS[END_WORD]})/ do
             push :"params#{name}"
@@ -163,6 +163,11 @@ def self.gen_delimiter_states(name, close, opts={})
         rule %r/\\./m, Str::Escape
       end
 
+      state :comment do
+        rule %r/.*[^\\]\n/, Comment, :pop!
+        rule %r/.*\\\n/, Comment
+      end
+
       state :string do
         rule %r/"/, Str::Double, :pop!
         mixin :interp

spec/visual/samples/tcl

@@ -323,3 +323,16 @@ test parse-1.63 "unquoted dollar sign" {
 } {x$}
 
 testreport
+
+# The braced form of variable substitution handles more complex variable names:
+set greeting "Hello, ${first name}"
+
+# "set" can always be used instead of variable substitution, and can handle all
+# variable names:
+set greeting "Hello, [set {first name}]"
+
+
+# To unpack a list into the command, use the expansion operator, "{*}".  These
+# two commands are equivalent:
+set name Neo
+set {*}{name Neo}