treetop parser?

.gitignore

@@ -0,0 +1,3 @@
+Gemfile.lock
+.bundle
+

bbsandbox.rb

@@ -3,8 +3,9 @@ require 'slim'
 require 'digest/sha1'
 require 'bb-ruby'
 require 'ruby-bbcode'
+require './bristle.rb'
 
-@@engines = ['bb-ruby', 'ruby-bbcode', 'raw']
+@@engines = ['bb-ruby', 'ruby-bbcode', 'raw', 'bristle']
 
 get '/' do
   @posts = list_posts
@@ -35,6 +36,8 @@ def exec_bbcode(engine, body)
     BBRuby.to_html body
   when "ruby-bbcode"
     RubyBBCode.to_html body
+  when "bristle"
+    Bristle.parse body
   when "raw"
     body
   else

bristle.rb

@@ -0,0 +1,18 @@
+require 'sanitize'
+require 'treetop'
+
+base_path = File.expand_path(File.dirname(__FILE__))
+require File.join(base_path, 'bristlecode_nodes.rb')
+
+class Bristle
+  Treetop.load(File.join(File.expand_path(File.dirname(__FILE__)), 'bristlecode_parser.treetop'))
+  @@parser = BristlecodeParser.new
+
+  def self.parse(doc)
+    tree = @@parser.parse(doc)
+    if tree.nil?
+      raise Exception, "Bristlecode parse error at offset: #{@@parser.index}"
+    end
+    tree
+  end
+end

bristlecode_nodes.rb

@@ -0,0 +1,37 @@
+module Bristlecode
+  class RootNode < Treetop::Runtime::SyntaxNode
+    def to_html
+      elements.each{|elem| elem.to_html} 
+    end
+  end
+
+  class TextNode < Treetop::Runtime::SyntaxNode
+    def initialize(input, interval, elements)
+      @text = input[interval]
+    end
+
+    def text_value
+      @text
+    end
+
+    def inspect(indent="")
+      "#{indent}TextNode: #{text_value}"
+    end
+
+    def to_html
+      text_value 
+    end
+  end
+
+  class BoldOpenNode < Treetop::Runtime::SyntaxNode
+  end
+
+  class BoldCloseNode < Treetop::Runtime::SyntaxNode
+  end
+
+  class BoldNode < Treetop::Runtime::SyntaxNode
+  end
+
+  class TagNode < Treetop::Runtime::SyntaxNode
+  end
+end

bristlecode_parser.treetop

@@ -0,0 +1,32 @@
+grammar Bristlecode
+  rule root
+    (tag / text)+ <RootNode>
+  end
+
+  rule text
+    (!tag .)+ <TextNode>
+  end
+
+  rule tag
+    (bold) <TagNode>
+  end
+
+  ##############################
+  # bold
+  ##############################
+
+  rule bold
+    bold_open
+    ((!bold_close .)+ <TextNode>)
+    bold_close
+    <BoldNode>
+  end
+
+  rule bold_open
+    '[b]' <BoldOpenNode> / '[B]' <BoldOpenNode>
+  end
+
+  rule bold_close
+    '[/b]' <BoldCloseNode> / '[/B]' <BoldCloseNode>
+  end
+end