http://magazine.rubyist.net/?0010-CodeReview-pukipa.rb

pukipa.rb

#!/usr/bin/env ruby

require 'logger'
require 'strscan'
require 'uri'

class PukipaParseError < StandardError;
end

class Pukipa
  def initialize(plain)
    @plain = plain
    @log = Logger::new($deferr)
    @log.level = $DEBUG ?
        Logger::DEBUG :
        ($VERBOSE ? Logger::INFO : Logger::WARN)
    @h_start_level = 2
    @pagelist = nil
  end

  # arrayでpagelistを渡す
  # pagelistはwikiページ一覧
  def pagelist(pagelist, base_uri = '/', suffix = '/')
    @base_uri = base_uri
    @pagelist_suffix = suffix
    if pagelist.size > 0
      #三文字以下はそもそも対象外
      pagelist.reject! { |pn| pn.size <= 3 }
      pagelist.map! { |pn| Regexp.escape(pn) }
      @pagelist = Regexp.new('(?!<a.*?>.*?)((?:' + pagelist.join(')|(?:') + '))(?!.*?</a>)', Regexp::IGNORECASE)
    end
  end

  # htmlに変換して返す
  def to_html
    plain = @plain.gsub(/\r?\n/, "\n").chomp + "\n"
    result = []
    block_regex = /^([:\-+> ]).*\n(?:(?:\1.*\n)+)?/
    @scanner = StringScanner.new(plain)
    while [email protected]?
      if @scanner.scan(/^\n/)
        #空行
        #空行
      elsif @scanner.scan(/^----.*?\n/)
        result << '<hr />'
      elsif @scanner.scan(block_regex)
        result << block_parse(@scanner.matched)
      elsif @scanner.scan(/^\*.*?\n/)
        result << h_parse(@scanner.matched)
      elsif @scanner.scan(/^([^*:\-+> \n].+?\n){1,}/)
        result << block_parse(@scanner.matched)
      elsif @scanner.scan(/(.*)/)
        result << block_parse(@scanner.matched)
      else
        #ここにはこないはずなので・・・
        raise PukipaParseError.new
      end
    end
    result.join("\n")
  end

  protected
  # h(見出し) のパーサ
  def h_parse(str)
    str.chomp!

    h_regexs = {
        '*' => 'h' + @h_start_level.to_s,
        '**' => 'h' + (@h_start_level + 1).to_s,
        '***' => 'h' + (@h_start_level + 2).to_s,
        '****' => 'h' + (@h_start_level + 3).to_s,
    }
    h_regexs.each do |tmp_regex, prefix|
      regex = Regexp.new('^' + Regexp.escape(tmp_regex) + '([^*])')
      if str =~ regex
        str.gsub!(regex, "\\1").gsub!(/^\s+/, '')
        str = "<%s>%s</%s>" % [prefix, str_parse(str), prefix]
        break
      end
    end
    @log.debug "inline:\n%s" % str
    str
  end

  #blockなもののパーサ
  def block_parse(str)
    str.chomp!

    if str =~ /^ /
      str = str.chars.map { |s| s.gsub(/^ /, '') }.join
      # preの時はstr_parseしない
      str = ['<pre><code>' + escapeHTML(str), '</code></pre>'].join "\n"
    elsif str =~ /^>/
      str = str.chars.map { |s| s.gsub(/^>/, '') }.join
      str = ['<blockquote><p>', str_parse(str), '</p></blockquote>'].join "\n"
    elsif str =~ /^-/
      str = list_parse(str, 'ul')
    elsif str =~ /^\+/
      str = list_parse(str, 'ol')
    elsif str =~ /^:/
      str = dl_parse(str)
    else
      str = ['<p>', str_parse(str), '</p>'].join "\n"
    end
    @log.debug "block:\n%s" % str
    str
  end

  # liのパーサ
  def list_parse(str, list)
    if list == 'ul'
      regex = /^-/
    else
      regex = /^\+/
    end
    str = str.chars.map { |s| s.gsub(regex, '') }.join
    result = []
    result << "<#{list}>"
    tmp = []
    str.each_line do |s|
      s.chomp!
      if s =~ regex
        tmp << s.gsub(regex, '')
      else
        if tmp.size > 0
          result.pop
          result << list_parse(tmp.join("\n"), list)
          result << "</li>"
          tmp.clear
        end
        result << "<li>#{str_parse(s)}"
        result << "</li>"
      end
    end
    if tmp.size > 0
      result.pop
      result << list_parse(tmp.join("\n"), list)
      result << "</li>"
      tmp.clear
    end
    result << "</#{list}>"
    result.join "\n"
  end

  # dlのパーサ
  def dl_parse(str)
    regex = /^:/
    regex2 = /(.*?)\|(.*)/
    str = str.chars.map { |s| s.gsub(regex, '') }.join
    result = []
    result << "<dl>"
    tmp = []
    str.each_line do |s|
      s.chomp!
      m = regex2.match(s)
      if m
        result << "<dt>" + str_parse(m[1]) + "</dt>"
        result << "<dd>" + str_parse(m[2]) + "</dd>"
      else
        result << "<dt>" + str_parse(s) + "</dt>"
      end
    end
    result << "</dl>"
    result.join "\n"
  end

  #文字列のパーサ
  def str_parse(str)
    #URIへの自動リンクは一番最初にやる
    uri_regex = Regexp.new('(?!\[\[.*?)(' + URI.regexp('http').source + ')(?!.*?\]\])', Regexp::EXTENDED)
    str.gsub!(uri_regex) do |match|
      uri = $1.dup
      re = match
      re = '[[%s:%s]]' % [uri, uri] if not uri =~ /\]\]$/
      re
    end

    str = escapeHTML(str)

    #リンク
    str.gsub!(/\[\[(.+?):\s*(https?:\/\/.+?)\s*\]\]/) do
      name = $1.dup
      uri = $2.dup
      '<a class="outlink" href="%s">%s</a>' % [uri, name]
    end

    #ページにリンク
    if @pagelist
      str.gsub!(@pagelist) do
        s = $1.dup
        '<a class="pagelink" href="%s%s%s">%s</a>' % [@base_uri, escape(s), @pagelist_suffix, s]
      end
    end

    str
  end

  def escapeHTML(string)
    string.gsub(/&/n, '&amp;').gsub(/\"/n, '&quot;').gsub(/>/n, '&gt;').gsub(/</n, '&lt;')
  end

  def escape(string)
    string.gsub(/([^ a-zA-Z0-9_.-]+)/n) do
      '%' + $1.unpack('H2' * $1.size).join('%').upcase
    end.tr(' ', '+')
  end
end

if $0 == __FILE__
  body =<<EOF
*Wiki文法

**見出し
 *h2
 **h3
 ***h4
 ****h5
*h2
**h3
***h4
****h5

**リスト
 -list
 -list2
 --list2-1
 --list2-2
-list
-list2
--list2-1
--list2-2

**番号付きリスト
 +olist
 +olist2
 ++olist2-1
 ++olist2-2
+olist
+olist2
++olist2-1
++olist2-2

**引用
 >引用文
 >example
>引用文
>example

**pre
頭にスペースを入れる
 def takahashi
   'takahashi'
 end

**定義語
 :apple|リンゴ
 :orange|オランゲ
:apple|リンゴ
:orange|オランゲ

**リンク
 [[example:http://example.com]]
[[example:http://example.com]]

ページ名には自動リンクされる。

例:)文法
EOF
  pu = Pukipa.new(body)
  pu.pagelist(['文法', '自動リンク'])
  puts pu.to_html
end