Improve handling of quoted forms in Janet lexer (#1586)

This commit makes a number of fixes to the Janet lexer. Specifically,
it:

- supports quoting structs/tables;
- fixes quoting of arrays and tables; and
- removes unnecessary backslashes in character classes.

lib/rouge/lexers/janet.rb

@@ -114,7 +114,7 @@ def name_token(name)
         end
       end
 
-      punctuation = %r/[_!@$%^&*+=~<>.?\/-]/o
+      punctuation = %r/[_!$%^&*+=~<>.?\/-]/o
       symbol = %r/([[:alpha:]]|#{punctuation})([[:word:]]|#{punctuation}|:)*/o
 
       state :root do
@@ -143,20 +143,19 @@ def name_token(name)
 
         rule %r/\(/, Punctuation, :function
 
-        rule %r/(')([\(\[])/ do
+        rule %r/(')(@?[(\[{])/ do
           groups Operator, Punctuation
           push :quote
         end
 
-        rule %r/(~)([\(\[])/ do
+        rule %r/(~)(@?[(\[{])/ do
           groups Operator, Punctuation
           push :quasiquote
         end
 
         rule %r/[\#~,';\|]/, Operator
 
-        rule %r/@?[({\[]/, Punctuation, :push
-        rule %r/[)}\]]/, Punctuation, :pop!
+        rule %r/@?[(){}\[\]]/, Punctuation
 
         rule symbol, Name
       end
@@ -169,6 +168,8 @@ def name_token(name)
       end
 
       state :function do
+        rule %r/[\)]/, Punctuation, :pop!
+
         rule symbol do |m|
           case m[0]
           when "quote"
@@ -187,8 +188,9 @@ def name_token(name)
       end
 
       state :quote do
-        rule %r/[\(\[]/, Punctuation, :push
-        rule symbol, Str::Symbol
+        rule %r/[(\[{]/, Punctuation, :push
+        rule %r/[)\]}]/, Punctuation, :pop!
+        rule symbol, Str::Escape
         mixin :root
       end
 
@@ -199,7 +201,6 @@ def name_token(name)
         end
         rule %r/(\()(\s*)(unquote)(\s+)(\()/ do
           groups Punctuation, Text, Keyword, Text, Punctuation
-          push :root
           push :function
         end
 

spec/visual/samples/janet

@@ -130,6 +130,8 @@ Yet another buffer
 (def name 'myfunction)
 (def args '[x y z])
 (defn body '[(print x) (print y) (print z)])
+'{:foo (print "bar")}
+'@(print 1 2 3)
 
 # Quasiquotes
 ~x