1127 lines
29 KiB
Ruby
1127 lines
29 KiB
Ruby
#!/usr/bin/ruby
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#
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# Bluecloth is a Ruby implementation of Markdown, a text-to-HTML conversion
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# tool.
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#
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# == Synopsis
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#
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# doc = BlueCloth::new "
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# ## Test document ##
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#
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# Just a simple test.
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# "
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#
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# puts doc.to_html
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#
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# == Authors
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#
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# * Michael Granger <ged@FaerieMUD.org>
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#
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# == Contributors
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#
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# * Martin Chase <stillflame@FaerieMUD.org> - Peer review, helpful suggestions
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# * Florian Gross <flgr@ccan.de> - Filter options, suggestions
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#
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# == Copyright
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#
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# Original version:
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# Copyright (c) 2003-2004 John Gruber
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# <http://daringfireball.net/>
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# All rights reserved.
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#
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# Ruby port:
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# Copyright (c) 2004 The FaerieMUD Consortium.
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#
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# BlueCloth is free software; you can redistribute it and/or modify it under the
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# terms of the GNU General Public License as published by the Free Software
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# Foundation; either version 2 of the License, or (at your option) any later
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# version.
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#
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# BlueCloth is distributed in the hope that it will be useful, but WITHOUT ANY
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# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
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# A PARTICULAR PURPOSE. See the GNU General Public License for more details.
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#
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# == To-do
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#
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# * Refactor some of the larger uglier methods that have to do their own
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# brute-force scanning because of lack of Perl features in Ruby's Regexp
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# class. Alternately, could add a dependency on 'pcre' and use most Perl
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# regexps.
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#
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# * Put the StringScanner in the render state for thread-safety.
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#
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# == Version
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#
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# $Id: bluecloth.rb,v 1.3 2004/05/02 15:56:33 webster132 Exp $
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#
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require 'digest/md5'
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require 'logger'
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require 'strscan'
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### BlueCloth is a Ruby implementation of Markdown, a text-to-HTML conversion
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### tool.
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class BlueCloth < String
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### Exception class for formatting errors.
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class FormatError < RuntimeError
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### Create a new FormatError with the given source +str+ and an optional
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### message about the +specific+ error.
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def initialize( str, specific=nil )
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if specific
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msg = "Bad markdown format near %p: %s" % [ str, specific ]
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else
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msg = "Bad markdown format near %p" % str
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end
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super( msg )
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end
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end
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# Release Version
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Version = '0.0.3'
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# SVN Revision
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SvnRev = %q$Rev: 37 $
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# SVN Id tag
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SvnId = %q$Id: bluecloth.rb,v 1.3 2004/05/02 15:56:33 webster132 Exp $
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# SVN URL
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SvnUrl = %q$URL: svn+ssh://cvs.faeriemud.org/var/svn/BlueCloth/trunk/lib/bluecloth.rb $
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# Rendering state struct. Keeps track of URLs, titles, and HTML blocks
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# midway through a render. I prefer this to the globals of the Perl version
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# because globals make me break out in hives. Or something.
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RenderState = Struct::new( "RenderState", :urls, :titles, :html_blocks, :log )
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# Tab width for #detab! if none is specified
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TabWidth = 4
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# The tag-closing string -- set to '>' for HTML
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EmptyElementSuffix = "/>";
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# Table of MD5 sums for escaped characters
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EscapeTable = {}
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'\\`*_{}[]()#.!'.split(//).each {|char|
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hash = Digest::MD5::hexdigest( char )
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EscapeTable[ char ] = {
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:md5 => hash,
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:md5re => Regexp::new( hash ),
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:re => Regexp::new( '\\\\' + Regexp::escape(char) ),
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}
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}
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#################################################################
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### I N S T A N C E M E T H O D S
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#################################################################
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### Create a new BlueCloth string.
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def initialize( content="", *restrictions )
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@log = Logger::new( $deferr )
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@log.level = $DEBUG ?
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Logger::DEBUG :
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($VERBOSE ? Logger::INFO : Logger::WARN)
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@scanner = nil
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# Add any restrictions, and set the line-folding attribute to reflect
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# what happens by default.
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restrictions.flatten.each {|r| __send__("#{r}=", true) }
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@fold_lines = true
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super( content )
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@log.debug "String is: %p" % self
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end
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######
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public
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######
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# Filters for controlling what gets output for untrusted input. (But really,
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# you're filtering bad stuff out of untrusted input at submission-time via
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# untainting, aren't you?)
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attr_accessor :filter_html, :filter_styles
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# RedCloth-compatibility accessor. Line-folding is part of Markdown syntax,
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# so this isn't used by anything.
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attr_accessor :fold_lines
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### Render Markdown-formatted text in this string object as HTML and return
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### it. The parameter is for compatibility with RedCloth, and is currently
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### unused, though that may change in the future.
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def to_html( lite=false )
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# Create a StringScanner we can reuse for various lexing tasks
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@scanner = StringScanner::new( '' )
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# Make a structure to carry around stuff that gets placeholdered out of
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# the source.
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rs = RenderState::new( {}, {}, {} )
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# Make a copy of the string with normalized line endings, tabs turned to
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# spaces, and a couple of guaranteed newlines at the end
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text = self.gsub( /\r\n?/, "\n" ).detab
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text += "\n\n"
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@log.debug "Normalized line-endings: %p" % text
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# Filter HTML if we're asked to do so
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if self.filter_html
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text.gsub!( "<", "<" )
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text.gsub!( ">", ">" )
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@log.debug "Filtered HTML: %p" % text
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end
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# Simplify blank lines
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text.gsub!( /^ +$/, '' )
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@log.debug "Tabs -> spaces/blank lines stripped: %p" % text
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# Replace HTML blocks with placeholders
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text = hide_html_blocks( text, rs )
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@log.debug "Hid HTML blocks: %p" % text
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@log.debug "Render state: %p" % rs
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# Strip link definitions, store in render state
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text = strip_link_definitions( text, rs )
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@log.debug "Stripped link definitions: %p" % text
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@log.debug "Render state: %p" % rs
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# Escape meta-characters
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text = escape_special_chars( text )
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@log.debug "Escaped special characters: %p" % text
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# Transform block-level constructs
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text = apply_block_transforms( text, rs )
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@log.debug "After block-level transforms: %p" % text
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# Now swap back in all the escaped characters
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text = unescape_special_chars( text )
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@log.debug "After unescaping special characters: %p" % text
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return text
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end
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### Convert tabs in +str+ to spaces.
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def detab( tabwidth=TabWidth )
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copy = self.dup
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copy.detab!( tabwidth )
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return copy
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end
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### Convert tabs to spaces in place and return self if any were converted.
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def detab!( tabwidth=TabWidth )
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newstr = self.split( /\n/ ).collect {|line|
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line.gsub( /(.*?)\t/ ) do
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$1 + ' ' * (tabwidth - $1.length % tabwidth)
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end
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}.join("\n")
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self.replace( newstr )
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end
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#######
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#private
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#######
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### Do block-level transforms on a copy of +str+ using the specified render
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### state +rs+ and return the results.
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def apply_block_transforms( str, rs )
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# Port: This was called '_runBlockGamut' in the original
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@log.debug "Applying block transforms to:\n %p" % str
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text = transform_headers( str, rs )
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text = transform_hrules( text, rs )
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text = transform_lists( text, rs )
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text = transform_code_blocks( text, rs )
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text = transform_block_quotes( text, rs )
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text = transform_auto_links( text, rs )
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text = hide_html_blocks( text, rs )
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text = form_paragraphs( text, rs )
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@log.debug "Done with block transforms:\n %p" % text
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return text
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end
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### Apply Markdown span transforms to a copy of the specified +str+ with the
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### given render state +rs+ and return it.
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def apply_span_transforms( str, rs )
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@log.debug "Applying span transforms to:\n %p" % str
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str = transform_code_spans( str, rs )
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str = encode_html( str )
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str = transform_images( str, rs )
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str = transform_anchors( str, rs )
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str = transform_italic_and_bold( str, rs )
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# Hard breaks
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str.gsub!( / {2,}\n/, "<br#{EmptyElementSuffix}\n" )
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@log.debug "Done with span transforms:\n %p" % str
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return str
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end
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# The list of tags which are considered block-level constructs and an
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# alternation pattern suitable for use in regexps made from the list
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BlockTags = %w[ p div h[1-6] blockquote pre table dl ol ul script ]
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BlockTagPattern = BlockTags.join('|')
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# Nested blocks:
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# <div>
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# <div>
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# tags for inner block must be indented.
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# </div>
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# </div>
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StrictBlockRegex = %r{
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^ # Start of line
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<(#{BlockTagPattern}) # Start tag: \2
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\b # word break
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(.*\n)*? # Any number of lines, minimal match
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</\1> # Matching end tag
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[ ]* # trailing spaces
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(?=\n+|\Z) # End of line or document
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}ix
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# More-liberal block-matching
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LooseBlockRegex = %r{
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^ # Start of line
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<(#{BlockTagPattern}) # start tag: \2
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\b # word break
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(.*\n)*? # Any number of lines, minimal match
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.*</\1> # Anything + Matching end tag
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[ ]* # trailing spaces
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(?=\n+|\Z) # End of line or document
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}ix
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# Special case for <hr />.
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HruleBlockRegex = %r{
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( # $1
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\A\n? # Start of doc + optional \n
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| # or
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.*\n\n # anything + blank line
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)
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( # save in $2
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[ ]* # Any spaces
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<hr # Tag open
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\b # Word break
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([^<>])*? # Attributes
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/?> # Tag close
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(?=\n\n|\Z) # followed by a blank line or end of document
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)
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}ix
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### Replace all blocks of HTML in +str+ that start in the left margin with
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### tokens.
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def hide_html_blocks( str, rs )
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@log.debug "Hiding HTML blocks in %p" % str
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# Tokenizer proc to pass to gsub
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tokenize = lambda {|match|
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key = Digest::MD5::hexdigest( match )
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rs.html_blocks[ key ] = match
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@log.debug "Replacing %p with %p" %
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[ match, key ]
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"\n\n#{key}\n\n"
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}
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rval = str.dup
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@log.debug "Finding blocks with the strict regex..."
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rval.gsub!( StrictBlockRegex, &tokenize )
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@log.debug "Finding blocks with the loose regex..."
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rval.gsub!( LooseBlockRegex, &tokenize )
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@log.debug "Finding hrules..."
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rval.gsub!( HruleBlockRegex ) {|match| $1 + tokenize[$2] }
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return rval
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end
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# Link defs are in the form: ^[id]: url "optional title"
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LinkRegex = %r{
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^[ ]*\[(.+)\]: # id = $1
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[ ]*
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\n? # maybe *one* newline
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[ ]*
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(\S+) # url = $2
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[ ]*
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\n? # maybe one newline
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[ ]*
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(?:
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# Titles are delimited by "quotes" or (parens).
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["(]
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(.+?) # title = $3
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[")] # Matching ) or "
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[ ]*
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)? # title is optional
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(?:\n+|\Z)
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}x
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### Strip link definitions from +str+, storing them in the given RenderState
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### +rs+.
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def strip_link_definitions( str, rs )
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str.gsub( LinkRegex ) {|match|
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id, url, title = $1, $2, $3
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rs.urls[ id.downcase ] = encode_html( url )
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unless title.nil?
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rs.titles[ id.downcase ] = title.gsub( /"/, """ )
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end
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""
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}
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end
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### Escape special characters in the given +str+
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def escape_special_chars( str )
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@log.debug " Escaping special characters"
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text = ''
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tokenize_html( str ) {|token, str|
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@log.debug " Adding %p token %p" % [ token, str ]
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case token
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# Within tags, encode * and _
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when :tag
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text += str.
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gsub( /\*/, EscapeTable['*'][:md5] ).
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gsub( /_/, EscapeTable['_'][:md5] )
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# Encode backslashed stuff in regular text
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when :text
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text += encode_backslash_escapes( str )
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else
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raise TypeError, "Unknown token type %p" % token
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end
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}
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@log.debug " Text with escapes is now: %p" % text
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return text
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end
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### Swap escaped special characters in a copy of the given +str+ and return
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### it.
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def unescape_special_chars( str )
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EscapeTable.each {|char, hash|
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@log.debug "Unescaping escaped %p with %p" %
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[ char, hash[:md5re] ]
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str.gsub!( hash[:md5re], char )
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}
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return str
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end
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### Return a copy of the given +str+ with any backslashed special character
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### in it replaced with MD5 placeholders.
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def encode_backslash_escapes( str )
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# Make a copy with any double-escaped backslashes encoded
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text = str.gsub( /\\\\/, EscapeTable['\\'][:md5] )
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EscapeTable.each_pair {|char, esc|
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next if char == '\\'
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text.gsub!( esc[:re], esc[:md5] )
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}
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return text
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end
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### Transform any Markdown-style horizontal rules in a copy of the specified
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### +str+ and return it.
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def transform_hrules( str, rs )
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@log.debug " Transforming horizontal rules"
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str.gsub( /^( ?[\-\*] ?){3,}$/, "\n<hr#{EmptyElementSuffix}\n" )
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end
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# Pattern to transform lists
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ListRegexp = %r{
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(?:
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^[ ]{0,#{TabWidth - 1}} # Indent < tab width
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(\*|\d+\.) # unordered or ordered ($1)
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[ ]+ # At least one space
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)
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(?m:.+?) # item content (include newlines)
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(?:
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\z # Either EOF
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| # or
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\n{2,} # Blank line...
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(?=\S) # ...followed by non-space
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(?![ ]* (\*|\d+\.) [ ]+) # ...but not another item
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)
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}x
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### Transform Markdown-style lists in a copy of the specified +str+ and
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### return it.
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def transform_lists( str, rs )
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@log.debug " Transforming lists at %p" % (str[0,100] + '...')
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str.gsub( ListRegexp ) {|list|
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@log.debug " Found list %p" % list
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list_type = ($1 == '*' ? "ul" : "ol")
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list.gsub!( /\n{2,}/, "\n\n\n" )
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%{<%s>\n%s</%s>\n} % [
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list_type,
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transform_list_items( list, rs ),
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list_type,
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]
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}
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end
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# Pattern for transforming list items
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ListItemRegexp = %r{
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(\n)? # leading line = $1
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(^[ ]*) # leading whitespace = $2
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(\*|\d+\.) [ ]+ # list marker = $3
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((?m:.+?) # list item text = $4
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(\n{1,2}))
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(?= \n* (\z | \2 (\*|\d+\.) [ ]+))
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}x
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### Transform list items in a copy of the given +str+ and return it.
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def transform_list_items( str, rs )
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@log.debug " Transforming list items"
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# Trim trailing blank lines
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str = str.sub( /\n{2,}\z/, "\n" )
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str.gsub( ListItemRegexp ) {|line|
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@log.debug " Found item line %p" % line
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leading_line, item = $1, $4
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if leading_line or /\n{2,}/.match( item )
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@log.debug " Found leading line or item has a blank"
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item = apply_block_transforms( outdent(item), rs )
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else
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# Recursion for sub-lists
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@log.debug " Recursing for sublist"
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item = transform_lists( outdent(item), rs ).chomp
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item = apply_span_transforms( item, rs )
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end
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%{<li>%s</li>\n} % item
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}
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end
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# Pattern for matching codeblocks
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CodeBlockRegexp = %r{
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(.?) # $1 = preceding character
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:\n+ # colon + NL delimiter
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( # $2 = the code block
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(?:
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(?:[ ]{#{TabWidth}} | \t) # a tab or tab-width of spaces
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.*\n+
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)+
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)
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((?=^[ ]{0,#{TabWidth}}\S)|\Z) # Lookahead for non-space at
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# line-start, or end of doc
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}x
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### Transform Markdown-style codeblocks in a copy of the specified +str+ and
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### return it.
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def transform_code_blocks( str, rs )
|
|
@log.debug " Transforming code blocks"
|
|
|
|
str.gsub( CodeBlockRegexp ) {|block|
|
|
prevchar, codeblock = $1, $2
|
|
|
|
@log.debug " prevchar = %p" % prevchar
|
|
|
|
# Generated the codeblock
|
|
%{%s\n\n<pre><code>%s\n</code></pre>\n\n} % [
|
|
(prevchar.empty? || /\s/ =~ prevchar) ? "" : "#{prevchar}:",
|
|
encode_code( outdent(codeblock), rs ).rstrip,
|
|
]
|
|
}
|
|
end
|
|
|
|
|
|
# Pattern for matching Markdown blockquote blocks
|
|
BlockQuoteRegexp = %r{
|
|
(?:
|
|
^[ ]*>[ ]? # '>' at the start of a line
|
|
.+\n # rest of the first line
|
|
(?:.+\n)* # subsequent consecutive lines
|
|
\n* # blanks
|
|
)+
|
|
}x
|
|
|
|
### Transform Markdown-style blockquotes in a copy of the specified +str+
|
|
### and return it.
|
|
def transform_block_quotes( str, rs )
|
|
@log.debug " Transforming block quotes"
|
|
|
|
str.gsub( BlockQuoteRegexp ) {|quote|
|
|
@log.debug "Making blockquote from %p" % quote
|
|
quote.gsub!( /^[ ]*>[ ]?/, '' )
|
|
%{<blockquote>\n%s\n</blockquote>\n\n} %
|
|
apply_block_transforms( quote, rs ).
|
|
gsub( /^/, " " * TabWidth )
|
|
}
|
|
end
|
|
|
|
|
|
AutoAnchorURLRegexp = /<((https?|ftp):[^'">\s]+)>/
|
|
AutoAnchorEmailRegexp = %r{
|
|
<
|
|
(
|
|
[-.\w]+
|
|
\@
|
|
[-a-z0-9]+(\.[-a-z0-9]+)*\.[a-z]+
|
|
)
|
|
>
|
|
}x
|
|
|
|
### Transform URLs in a copy of the specified +str+ into links and return
|
|
### it.
|
|
def transform_auto_links( str, rs )
|
|
@log.debug " Transforming auto-links"
|
|
str.gsub( AutoAnchorURLRegexp, %{<a href="\\1">\\1</a>}).
|
|
gsub( AutoAnchorEmailRegexp ) {|addr|
|
|
encode_email_address( unescape_special_chars($1) )
|
|
}
|
|
end
|
|
|
|
|
|
# Encoder functions to turn characters of an email address into encoded
|
|
# entities.
|
|
Encoders = [
|
|
lambda {|char| "&#%03d;" % char},
|
|
lambda {|char| "&#x%X;" % char},
|
|
lambda {|char| char.chr },
|
|
]
|
|
|
|
### Transform a copy of the given email +addr+ into an escaped version safer
|
|
### for posting publicly.
|
|
def encode_email_address( addr )
|
|
|
|
rval = ''
|
|
("mailto:" + addr).each_byte {|b|
|
|
case b
|
|
when ?:
|
|
rval += ":"
|
|
when ?@
|
|
rval += Encoders[ rand(2) ][ b ]
|
|
else
|
|
r = rand(100)
|
|
rval += (
|
|
r > 90 ? Encoders[2][ b ] :
|
|
r < 45 ? Encoders[1][ b ] :
|
|
Encoders[0][ b ]
|
|
)
|
|
end
|
|
}
|
|
|
|
return %{<a href="%s">%s</a>} % [ rval, rval.sub(/.+?:/, '') ]
|
|
end
|
|
|
|
|
|
# Regex for matching Setext-style headers
|
|
SetextHeaderRegexp = %r{
|
|
(.+) # The title text ($1)
|
|
\n
|
|
([\-=])+ # Match a line of = or -. Save only one in $2.
|
|
[ ]*\n+
|
|
}x
|
|
|
|
# Regexp for matching ATX-style headers
|
|
AtxHeaderRegexp = %r{
|
|
^(\#{1,6}) # $1 = string of #'s
|
|
[ ]*
|
|
(.+?) # $2 = Header text
|
|
[ ]*
|
|
\#* # optional closing #'s (not counted)
|
|
\n+
|
|
}x
|
|
|
|
### Apply Markdown header transforms to a copy of the given +str+ amd render
|
|
### state +rs+ and return the result.
|
|
def transform_headers( str, rs )
|
|
@log.debug " Transforming headers"
|
|
|
|
# Setext-style headers:
|
|
# Header 1
|
|
# ========
|
|
#
|
|
# Header 2
|
|
# --------
|
|
#
|
|
str.
|
|
gsub( SetextHeaderRegexp ) {|m|
|
|
@log.debug "Found setext-style header"
|
|
title, hdrchar = $1, $2
|
|
title = apply_span_transforms( title, rs )
|
|
|
|
case hdrchar
|
|
when '='
|
|
%[<h1>#{title}</h1>\n\n]
|
|
when '-'
|
|
%[<h2>#{title}</h2>\n\n]
|
|
else
|
|
title
|
|
end
|
|
}.
|
|
|
|
gsub( AtxHeaderRegexp ) {|m|
|
|
@log.debug "Found ATX-style header"
|
|
hdrchars, title = $1, $2
|
|
title = apply_span_transforms( title, rs )
|
|
|
|
level = hdrchars.length
|
|
%{<h%d>%s</h%d>\n\n} % [ level, title, level ]
|
|
}
|
|
end
|
|
|
|
|
|
### Wrap all remaining paragraph-looking text in a copy of +str+ inside <p>
|
|
### tags and return it.
|
|
def form_paragraphs( str, rs )
|
|
@log.debug " Forming paragraphs"
|
|
grafs = str.
|
|
sub( /\A\n+/, '' ).
|
|
sub( /\n+\z/, '' ).
|
|
split( /\n{2,}/ )
|
|
|
|
rval = grafs.collect {|graf|
|
|
|
|
# Unhashify HTML blocks if this is a placeholder
|
|
if rs.html_blocks.key?( graf )
|
|
rs.html_blocks[ graf ]
|
|
|
|
# Otherwise, wrap in <p> tags
|
|
else
|
|
apply_span_transforms(graf, rs).
|
|
sub( /^[ ]*/, '<p>' ) + '</p>'
|
|
end
|
|
}.join( "\n\n" )
|
|
|
|
@log.debug " Formed paragraphs: %p" % rval
|
|
return rval
|
|
end
|
|
|
|
|
|
# Pattern to match the linkid part of an anchor tag for reference-style
|
|
# links.
|
|
RefLinkIdRegex = %r{
|
|
[ ]? # Optional leading space
|
|
(?:\n[ ]*)? # Optional newline + spaces
|
|
\[
|
|
(.*?) # Id = $1
|
|
\]
|
|
}x
|
|
|
|
InlineLinkRegex = %r{
|
|
\( # Literal paren
|
|
[ ]* # Zero or more spaces
|
|
(.*?) # URI = $1
|
|
[ ]* # Zero or more spaces
|
|
(?: #
|
|
([\"\']) # Opening quote char = $2
|
|
(.*?) # Title = $3
|
|
\2 # Matching quote char
|
|
)? # Title is optional
|
|
\)
|
|
}x
|
|
|
|
### Apply Markdown anchor transforms to a copy of the specified +str+ with
|
|
### the given render state +rs+ and return it.
|
|
def transform_anchors( str, rs )
|
|
@log.debug " Transforming anchors"
|
|
@scanner.string = str.dup
|
|
text = ''
|
|
|
|
# Scan the whole string
|
|
until @scanner.empty?
|
|
|
|
if @scanner.scan( /\[/ )
|
|
link = ''; linkid = ''
|
|
depth = 1
|
|
startpos = @scanner.pos
|
|
@log.debug " Found a bracket-open at %d" % startpos
|
|
|
|
# Scan the rest of the tag, allowing unlimited nested []s. If
|
|
# the scanner runs out of text before the opening bracket is
|
|
# closed, append the text and return (wasn't a valid anchor).
|
|
while depth.nonzero?
|
|
linktext = @scanner.scan_until( /\]|\[/ )
|
|
|
|
if linktext
|
|
@log.debug " Found a bracket at depth %d: %p" %
|
|
[ depth, linktext ]
|
|
link += linktext
|
|
|
|
# Decrement depth for each closing bracket
|
|
depth += ( linktext[-1, 1] == ']' ? -1 : 1 )
|
|
@log.debug " Depth is now #{depth}"
|
|
|
|
# If there's no more brackets, it must not be an anchor, so
|
|
# just abort.
|
|
else
|
|
@log.debug " Missing closing brace, assuming non-link."
|
|
link += @scanner.rest
|
|
@scanner.terminate
|
|
return text + '[' + link
|
|
end
|
|
end
|
|
link.slice!( -1 ) # Trim final ']'
|
|
@log.debug " Found leading link %p" % link
|
|
|
|
# Look for a reference-style second part
|
|
if @scanner.scan( RefLinkIdRegex )
|
|
linkid = @scanner[1]
|
|
linkid = link.dup if linkid.empty?
|
|
linkid.downcase!
|
|
@log.debug " Found a linkid: %p" % linkid
|
|
|
|
# If there's a matching link in the link table, build an
|
|
# anchor tag for it.
|
|
if rs.urls.key?( linkid )
|
|
@log.debug " Found link key in the link table: %p" %
|
|
rs.urls[linkid]
|
|
url = escape_md( rs.urls[linkid] )
|
|
|
|
text += %{<a href="#{url}"}
|
|
if rs.titles.key?(linkid)
|
|
text += %{ title="%s"} % escape_md( rs.titles[linkid] )
|
|
end
|
|
text += %{>#{link}</a>}
|
|
|
|
# If the link referred to doesn't exist, just append the raw
|
|
# source to the result
|
|
else
|
|
@log.debug " Linkid %p not found in link table" % linkid
|
|
@log.debug " Appending original string instead: %p" %
|
|
@scanner.string[ startpos-1 .. @scanner.pos ]
|
|
text += @scanner.string[ startpos-1 .. @scanner.pos ]
|
|
end
|
|
|
|
# ...or for an inline style second part
|
|
elsif @scanner.scan( InlineLinkRegex )
|
|
url = @scanner[1]
|
|
title = @scanner[3]
|
|
@log.debug " Found an inline link to %p" % url
|
|
|
|
text += %{<a href="%s"} % escape_md( url )
|
|
if title
|
|
text += %{ title="%s"} % escape_md( title )
|
|
end
|
|
text += %{>#{link}</a>}
|
|
|
|
# No linkid part: just append the first part as-is.
|
|
else
|
|
@log.debug "No linkid, so no anchor. Appending literal text."
|
|
text += @scanner.string[ startpos-1 .. @scanner.pos-1 ]
|
|
end # if linkid
|
|
|
|
# Plain text
|
|
else
|
|
@log.debug " Scanning to the next link from %p" % @scanner.rest
|
|
text += @scanner.scan( /[^\[]+/ )
|
|
end
|
|
|
|
end # until @scanner.empty?
|
|
|
|
return text
|
|
end
|
|
|
|
# Pattern to match strong emphasis in Markdown text
|
|
BoldRegexp = %r{ (\*\*|__) (?=\S) (.+?\S) \1 }x
|
|
|
|
# Pattern to match normal emphasis in Markdown text
|
|
ItalicRegexp = %r{ (\*|_) (?=\S) (.+?\S) \1 }x
|
|
|
|
### Transform italic- and bold-encoded text in a copy of the specified +str+
|
|
### and return it.
|
|
def transform_italic_and_bold( str, rs )
|
|
@log.debug " Transforming italic and bold"
|
|
|
|
str.
|
|
gsub( BoldRegexp, %{<strong>\\2</strong>} ).
|
|
gsub( ItalicRegexp, %{<em>\\2</em>} )
|
|
end
|
|
|
|
|
|
### Transform backticked spans into <code> spans.
|
|
def transform_code_spans( str, rs )
|
|
@log.debug " Transforming code spans"
|
|
|
|
# Set up the string scanner and just return the string unless there's at
|
|
# least one backtick.
|
|
@scanner.string = str.dup
|
|
unless @scanner.exist?( /`/ )
|
|
@scanner.terminate
|
|
@log.debug "No backticks found for code span in %p" % str
|
|
return str
|
|
end
|
|
|
|
@log.debug "Transforming code spans in %p" % str
|
|
|
|
# Build the transformed text anew
|
|
text = ''
|
|
|
|
# Scan to the end of the string
|
|
until @scanner.empty?
|
|
|
|
# Scan up to an opening backtick
|
|
if pre = @scanner.scan_until( /.?(?=`)/m )
|
|
text += pre
|
|
@log.debug "Found backtick at %d after '...%s'" %
|
|
[ @scanner.pos, text[-10, 10] ]
|
|
|
|
# Make a pattern to find the end of the span
|
|
opener = @scanner.scan( /`+/ )
|
|
len = opener.length
|
|
closer = Regexp::new( opener )
|
|
@log.debug "Scanning for end of code span with %p" % closer
|
|
|
|
# Scan until the end of the closing backtick sequence. Chop the
|
|
# backticks off the resultant string, strip leading and trailing
|
|
# whitespace, and encode any enitites contained in it.
|
|
codespan = @scanner.scan_until( closer ) or
|
|
raise FormatError::new( @scanner.rest[0,20],
|
|
"No %p found before end" % opener )
|
|
|
|
@log.debug "Found close of code span at %d: %p" %
|
|
[ @scanner.pos - len, codespan ]
|
|
codespan.slice!( -len, len )
|
|
text += "<code>%s</code>" %
|
|
encode_code( codespan.strip, rs )
|
|
|
|
# If there's no more backticks, just append the rest of the string
|
|
# and move the scan pointer to the end
|
|
else
|
|
text += @scanner.rest
|
|
@scanner.terminate
|
|
end
|
|
end
|
|
|
|
return text
|
|
end
|
|
|
|
|
|
# Next, handle inline images: 
|
|
# Don't forget: encode * and _
|
|
InlineImageRegexp = %r{
|
|
( # Whole match = $1
|
|
!\[ (.*?) \] # alt text = $2
|
|
\([ ]* (\S+) [ ]* # source url = $3
|
|
( # title = $4
|
|
(["']) # quote char = $5
|
|
.*?
|
|
\5 # matching quote
|
|
[ ]*
|
|
)? # title is optional
|
|
\)
|
|
)
|
|
}xs #"
|
|
|
|
|
|
# Reference-style images
|
|
ReferenceImageRegexp = %r{
|
|
( # Whole match = $1
|
|
!\[ (.*?) \] # Alt text = $2
|
|
[ ]? # Optional space
|
|
(?:\n[ ]*)? # One optional newline + spaces
|
|
\[ (.*?) \] # id = $3
|
|
)
|
|
}xs
|
|
|
|
### Turn image markup into image tags.
|
|
def transform_images( str, rs )
|
|
@log.debug " Transforming images" % str
|
|
|
|
# Handle reference-style labeled images: ![alt text][id]
|
|
str.
|
|
gsub( ReferenceImageRegexp ) {|match|
|
|
whole, alt, linkid = $1, $2, $3.downcase
|
|
@log.debug "Matched %p" % match
|
|
res = nil
|
|
|
|
# for shortcut links like ![this][].
|
|
linkid = alt.downcase if linkid.empty?
|
|
|
|
if rs.urls.key?( linkid )
|
|
url = escape_md( rs.urls[linkid] )
|
|
@log.debug "Found url '%s' for linkid '%s' " %
|
|
[ url, linkid ]
|
|
|
|
# Build the tag
|
|
result = %{<img src="%s" alt="%s"} % [ url, alt ]
|
|
if rs.titles.key?( linkid )
|
|
result += %{ title="%s"} % escape_md( rs.titles[linkid] )
|
|
end
|
|
result += EmptyElementSuffix
|
|
|
|
else
|
|
result = whole
|
|
end
|
|
|
|
@log.debug "Replacing %p with %p" %
|
|
[ match, result ]
|
|
result
|
|
}.
|
|
|
|
# Inline image style
|
|
gsub( InlineImageRegexp ) {|match|
|
|
@log.debug "Found inline image %p" % match
|
|
whole, alt, title = $1, $2, $4
|
|
url = escape_md( $3 )
|
|
|
|
# Build the tag
|
|
result = %{<img src="%s" alt="%s"} % [ url, alt ]
|
|
unless title.nil?
|
|
result += %{ title="%s"} % escape_md( title.gsub(/^"|"$/, '') )
|
|
end
|
|
result += EmptyElementSuffix
|
|
|
|
@log.debug "Replacing %p with %p" %
|
|
[ match, result ]
|
|
result
|
|
}
|
|
end
|
|
|
|
|
|
# Regexp to match special characters in a code block
|
|
CodeEscapeRegexp = %r{( \* | _ | \{ | \} | \[ | \] )}x
|
|
|
|
### Escape any characters special to HTML and encode any characters special
|
|
### to Markdown in a copy of the given +str+ and return it.
|
|
def encode_code( str, rs )
|
|
str.gsub( %r{&}, '&' ).
|
|
gsub( %r{<}, '<' ).
|
|
gsub( %r{>}, '>' ).
|
|
gsub( CodeEscapeRegexp ) {|match| EscapeTable[match][:md5]}
|
|
end
|
|
|
|
|
|
|
|
#################################################################
|
|
### U T I L I T Y F U N C T I O N S
|
|
#################################################################
|
|
|
|
### Escape any markdown characters in a copy of the given +str+ and return
|
|
### it.
|
|
def escape_md( str )
|
|
str.
|
|
gsub( /\*/, '*' ).
|
|
gsub( /_/, '_' )
|
|
end
|
|
|
|
|
|
# Matching constructs for tokenizing X/HTML
|
|
HTMLCommentRegexp = %r{ <! ( -- .*? -- \s* )+ > }mx
|
|
XMLProcInstRegexp = %r{ <\? .*? \?> }mx
|
|
MetaTag = Regexp::union( HTMLCommentRegexp, XMLProcInstRegexp )
|
|
|
|
HTMLTagOpenRegexp = %r{ < [a-z/!$] [^<>]* }mx
|
|
HTMLTagCloseRegexp = %r{ > }x
|
|
HTMLTagPart = Regexp::union( HTMLTagOpenRegexp, HTMLTagCloseRegexp )
|
|
|
|
### Break the HTML source in +str+ into a series of tokens and return
|
|
### them. The tokens are just 2-element Array tuples with a type and the
|
|
### actual content. If this function is called with a block, the type and
|
|
### text parts of each token will be yielded to it one at a time as they are
|
|
### extracted.
|
|
def tokenize_html( str )
|
|
depth = 0
|
|
tokens = []
|
|
@scanner.string = str.dup
|
|
type, token = nil, nil
|
|
|
|
until @scanner.empty?
|
|
@log.debug "Scanning from %p" % @scanner.rest
|
|
|
|
# Match comments and PIs without nesting
|
|
if (( token = @scanner.scan(MetaTag) ))
|
|
type = :tag
|
|
|
|
# Do nested matching for HTML tags
|
|
elsif (( token = @scanner.scan(HTMLTagOpenRegexp) ))
|
|
tagstart = @scanner.pos
|
|
@log.debug " Found the start of a plain tag at %d" % tagstart
|
|
|
|
# Start the token with the opening angle
|
|
depth = 1
|
|
type = :tag
|
|
|
|
# Scan the rest of the tag, allowing unlimited nested <>s. If
|
|
# the scanner runs out of text before the tag is closed, raise
|
|
# an error.
|
|
while depth.nonzero?
|
|
|
|
# Scan either an opener or a closer
|
|
chunk = @scanner.scan( HTMLTagPart ) or
|
|
raise "Malformed tag at character %d: %p" %
|
|
[ tagstart, token + @scanner.rest ]
|
|
|
|
@log.debug " Found another part of the tag at depth %d: %p" %
|
|
[ depth, chunk ]
|
|
|
|
token += chunk
|
|
|
|
# If the last character of the token so far is a closing
|
|
# angle bracket, decrement the depth. Otherwise increment
|
|
# it for a nested tag.
|
|
depth += ( token[-1, 1] == '>' ? -1 : 1 )
|
|
@log.debug " Depth is now #{depth}"
|
|
end
|
|
|
|
# Match text segments
|
|
else
|
|
@log.debug " Looking for a chunk of text"
|
|
type = :text
|
|
|
|
# Scan forward, always matching at least one character to move
|
|
# the pointer beyond any non-tag '<'.
|
|
token = @scanner.scan_until( /[^<]+/m )
|
|
end
|
|
|
|
@log.debug " type: %p, token: %p" % [ type, token ]
|
|
|
|
# If a block is given, feed it one token at a time. Add the token to
|
|
# the token list to be returned regardless.
|
|
if block_given?
|
|
yield( type, token )
|
|
end
|
|
tokens << [ type, token ]
|
|
end
|
|
|
|
return tokens
|
|
end
|
|
|
|
|
|
### Return a copy of +str+ with angle brackets and ampersands HTML-encoded.
|
|
def encode_html( str )
|
|
str.gsub( /&(?!#?[x]?(?:[0-9a-f]+|\w{1,8});)/i, "&" ).
|
|
gsub( %r{<(?![a-z/?\$!])}i, "<" )
|
|
end
|
|
|
|
|
|
### Return one level of line-leading tabs or spaces from a copy of +str+ and
|
|
### return it.
|
|
def outdent( str )
|
|
str.gsub( /^(\t|[ ]{1,#{TabWidth}})/, '')
|
|
end
|
|
|
|
end # class BlueCloth
|
|
|