lib/spontaneous/utils/smart_quotes.rb
# encoding: UTF-8
#
# = RubyPants -- SmartyPants ported to Ruby
#
# Ported by Christian Neukirchen <mailto:chneukirchen@gmail.com>
# Copyright (C) 2004 Christian Neukirchen
#
# Incooporates ideas, comments and documentation by Chad Miller
# Copyright (C) 2004 Chad Miller
#
# Original SmartyPants by John Gruber
# Copyright (C) 2003 John Gruber
#
#
# = RubyPants -- SmartyPants ported to Ruby
#
# == Synopsis
#
# RubyPants is a Ruby port of the smart-quotes library SmartyPants.
#
# The original "SmartyPants" is a free web publishing plug-in for
# Movable Type, Blosxom, and BBEdit that easily translates plain ASCII
# punctuation characters into "smart" typographic punctuation HTML
# entities.
#
#
# == Description
#
# RubyPants can perform the following transformations:
#
# * Straight quotes (<tt>"</tt> and <tt>'</tt>) into "curly" quote
# HTML entities
# * Backticks-style quotes (<tt>``like this''</tt>) into "curly" quote
# HTML entities
# * Dashes (<tt>--</tt> and <tt>---</tt>) into en- and em-dash
# entities
# * Three consecutive dots (<tt>...</tt> or <tt>. . .</tt>) into an
# ellipsis entity
#
# This means you can write, edit, and save your posts using plain old
# ASCII straight quotes, plain dashes, and plain dots, but your
# published posts (and final HTML output) will appear with smart
# quotes, em-dashes, and proper ellipses.
#
# RubyPants does not modify characters within <tt><pre></tt>,
# <tt><code></tt>, <tt><kbd></tt>, <tt><math></tt> or
# <tt><script></tt> tag blocks. Typically, these tags are used to
# display text where smart quotes and other "smart punctuation" would
# not be appropriate, such as source code or example markup.
#
#
# == Backslash Escapes
#
# If you need to use literal straight quotes (or plain hyphens and
# periods), RubyPants accepts the following backslash escape sequences
# to force non-smart punctuation. It does so by transforming the
# escape sequence into a decimal-encoded HTML entity:
#
# \\ \" \' \. \- \`
#
# This is useful, for example, when you want to use straight quotes as
# foot and inch marks: 6'2" tall; a 17" iMac. (Use <tt>6\'2\"</tt>
# resp. <tt>17\"</tt>.)
#
#
# == Algorithmic Shortcomings
#
# One situation in which quotes will get curled the wrong way is when
# apostrophes are used at the start of leading contractions. For
# example:
#
# 'Twas the night before Christmas.
#
# In the case above, RubyPants will turn the apostrophe into an
# opening single-quote, when in fact it should be a closing one. I
# don't think this problem can be solved in the general case--every
# word processor I've tried gets this wrong as well. In such cases,
# it's best to use the proper HTML entity for closing single-quotes
# ("<tt>’</tt>") by hand.
#
#
# == Bugs
#
# To file bug reports or feature requests (except see above) please
# send email to: mailto:chneukirchen@gmail.com
#
# If the bug involves quotes being curled the wrong way, please send
# example text to illustrate.
#
#
# == Authors
#
# John Gruber did all of the hard work of writing this software in
# Perl for Movable Type and almost all of this useful documentation.
# Chad Miller ported it to Python to use with Pyblosxom.
#
# Christian Neukirchen provided the Ruby port, as a general-purpose
# library that follows the *Cloth API.
#
#
# == Copyright and License
#
# === SmartyPants license:
#
# Copyright (c) 2003 John Gruber
# (http://daringfireball.net)
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in
# the documentation and/or other materials provided with the
# distribution.
#
# * Neither the name "SmartyPants" nor the names of its contributors
# may be used to endorse or promote products derived from this
# software without specific prior written permission.
#
# This software is provided by the copyright holders and contributors
# "as is" and any express or implied warranties, including, but not
# limited to, the implied warranties of merchantability and fitness
# for a particular purpose are disclaimed. In no event shall the
# copyright owner or contributors be liable for any direct, indirect,
# incidental, special, exemplary, or consequential damages (including,
# but not limited to, procurement of substitute goods or services;
# loss of use, data, or profits; or business interruption) however
# caused and on any theory of liability, whether in contract, strict
# liability, or tort (including negligence or otherwise) arising in
# any way out of the use of this software, even if advised of the
# possibility of such damage.
#
# === RubyPants license
#
# RubyPants is a derivative work of SmartyPants and smartypants.py.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in
# the documentation and/or other materials provided with the
# distribution.
#
# This software is provided by the copyright holders and contributors
# "as is" and any express or implied warranties, including, but not
# limited to, the implied warranties of merchantability and fitness
# for a particular purpose are disclaimed. In no event shall the
# copyright owner or contributors be liable for any direct, indirect,
# incidental, special, exemplary, or consequential damages (including,
# but not limited to, procurement of substitute goods or services;
# loss of use, data, or profits; or business interruption) however
# caused and on any theory of liability, whether in contract, strict
# liability, or tort (including negligence or otherwise) arising in
# any way out of the use of this software, even if advised of the
# possibility of such damage.
#
#
# == Links
#
# John Gruber:: http://daringfireball.net
# SmartyPants:: http://daringfireball.net/projects/smartypants
#
# Chad Miller:: http://web.chad.org
#
# Christian Neukirchen:: http://kronavita.de/chris
#
module Spontaneous::Utils
module SmartQuotes
extend self
VERSION = "0.2"
OPEN_SGL_QUOTE = "‘"
CLOSE_SGL_QUOTE = "’"
OPEN_DBL_QUOTE = "“"
CLOSE_DBL_QUOTE = "”"
ELLIPSIS = "…"
EM_DASH = "—"
EN_DASH = "–"
# Create a new RubyPants instance with the text in +string+.
#
# Allowed elements in the options array:
#
# 0 :: do nothing
# 1 :: enable all, using only em-dash shortcuts
# 2 :: enable all, using old school en- and em-dash shortcuts (*default*)
# 3 :: enable all, using inverted old school en and em-dash shortcuts
# -1 :: stupefy (translate HTML entities to their ASCII-counterparts)
#
# If you don't like any of these defaults, you can pass symbols to change
# RubyPants' behavior:
#
# <tt>:quotes</tt> :: quotes
# <tt>:backticks</tt> :: backtick quotes (``double'' only)
# <tt>:allbackticks</tt> :: backtick quotes (``double'' and `single')
# <tt>:dashes</tt> :: dashes
# <tt>:oldschool</tt> :: old school dashes
# <tt>:inverted</tt> :: inverted old school dashes
# <tt>:ellipses</tt> :: ellipses
# <tt>:convertquotes</tt> :: convert <tt>"</tt> entities to
# <tt>"</tt> for Dreamweaver users
# <tt>:stupefy</tt> :: translate RubyPants HTML entities
# to their ASCII counterparts.
#
# Apply SmartyPants transformations.
def smarten(string, options=[2])
do_quotes = do_backticks = do_dashes = do_ellipses = do_stupify = nil
convert_quotes = false
if options.include? 0
# Do nothing.
return string
elsif options.include? 1
# Do everything, turn all options on.
do_quotes = do_backticks = do_ellipses = true
do_dashes = :normal
elsif options.include? 2
# Do everything, turn all options on, use old school dash shorthand.
do_quotes = do_backticks = do_ellipses = true
do_dashes = :oldschool
elsif options.include? 3
# Do everything, turn all options on, use inverted old school
# dash shorthand.
do_quotes = do_backticks = do_ellipses = true
do_dashes = :inverted
elsif options.include?(-1)
do_stupefy = true
else
do_quotes = options.include? :quotes
do_backticks = options.include? :backticks
do_backticks = :both if options.include? :allbackticks
do_dashes = :normal if options.include? :dashes
do_dashes = :oldschool if options.include? :oldschool
do_dashes = :inverted if options.include? :inverted
do_ellipses = options.include? :ellipses
convert_quotes = options.include? :convertquotes
do_stupefy = options.include? :stupefy
end
# Parse the HTML
tokens = tokenize(string)
# Keep track of when we're inside <pre> or <code> tags.
in_pre = false
# Here is the result stored in.
result = ""
# This is a cheat, used to get some context for one-character
# tokens that consist of just a quote char. What we do is remember
# the last character of the previous text token, to use as context
# to curl single- character quote tokens correctly.
prev_token_last_char = nil
tokens.each { |token|
if token.first == :tag
result << token[1]
if token[1] =~ %r!<(/?)(?:pre|code|kbd|script|math)[\s>]!
in_pre = ($1 != "/") # Opening or closing tag?
end
else
t = token[1]
# Remember last char of this token before processing.
last_char = t[-1].chr
unless in_pre
t = process_escapes t
t.gsub!(/"/, '"') if convert_quotes
if do_dashes
t = educate_dashes t if do_dashes == :normal
t = educate_dashes_oldschool t if do_dashes == :oldschool
t = educate_dashes_inverted t if do_dashes == :inverted
end
t = educate_ellipses t if do_ellipses
# Note: backticks need to be processed before quotes.
if do_backticks
t = educate_backticks t
t = educate_single_backticks t if do_backticks == :both
end
if do_quotes
if t == "'"
# Special case: single-character ' token
if prev_token_last_char =~ /\S/
t = CLOSE_SGL_QUOTE
else
t = OPEN_SGL_QUOTE
end
elsif t == '"'
# Special case: single-character " token
if prev_token_last_char =~ /\S/
t = CLOSE_DBL_QUOTE
else
t = OPEN_DBL_QUOTE
end
else
# Normal case:
t = educate_quotes t
end
end
t = stupefy_entities t if do_stupefy
end
prev_token_last_char = last_char
result << t
end
}
# Done
result
end
protected
# Return the string, with after processing the following backslash
# escape sequences. This is useful if you want to force a "dumb" quote
# or other character to appear.
#
# Escaped are:
# \\ \" \' \. \- \`
#
def process_escapes(str)
str.gsub('\\\\', '\\').
gsub('\"', '"').
gsub("\\\'", "'").
gsub('\.', '.').
gsub('\-', '-').
gsub('\`', '`')
end
# The string, with each instance of "<tt>--</tt>" translated to an
# em-dash HTML entity.
#
def educate_dashes(str)
str.gsub(/--/, EM_DASH)
end
# The string, with each instance of "<tt>--</tt>" translated to an
# en-dash HTML entity, and each "<tt>---</tt>" translated to an
# em-dash HTML entity.
#
def educate_dashes_oldschool(str)
str.gsub(/---/, EM_DASH).gsub(/--/, EN_DASH)
end
# Return the string, with each instance of "<tt>--</tt>" translated
# to an em-dash HTML entity, and each "<tt>---</tt>" translated to
# an en-dash HTML entity. Two reasons why: First, unlike the en- and
# em-dash syntax supported by +educate_dashes_oldschool+, it's
# compatible with existing entries written before SmartyPants 1.1,
# back when "<tt>--</tt>" was only used for em-dashes. Second,
# em-dashes are more common than en-dashes, and so it sort of makes
# sense that the shortcut should be shorter to type. (Thanks to
# Aaron Swartz for the idea.)
#
def educate_dashes_inverted(str)
str.gsub(/---/, EN_DASH).gsub(/--/, EM_DASH)
end
# Return the string, with each instance of "<tt>...</tt>" translated
# to an ellipsis HTML entity. Also converts the case where there are
# spaces between the dots.
#
def educate_ellipses(str)
str.gsub('...', ELLIPSIS).gsub('. . .', ELLIPSIS)
end
# Return the string, with "<tt>``backticks''</tt>"-style single quotes
# translated into HTML curly quote entities.
#
def educate_backticks(str)
str.gsub("``", OPEN_DBL_QUOTE).gsub("''", CLOSE_DBL_QUOTE)
end
# Return the string, with "<tt>`backticks'</tt>"-style single quotes
# translated into HTML curly quote entities.
#
def educate_single_backticks(str)
str.gsub("`", OPEN_SGL_QUOTE).gsub("'", CLOSE_SGL_QUOTE)
end
# Return the string, with "educated" curly quote HTML entities.
#
def educate_quotes(str)
punct_class = '[!"#\$\%\'()*+,\-.\/:;<=>?\@\[\\\\\]\^_`{|}~]'
str = str.dup
# Special case if the very first character is a quote followed by
# punctuation at a non-word-break. Close the quotes by brute
# force:
str.gsub!(/^'(?=#{punct_class}\B)/, CLOSE_SGL_QUOTE)
str.gsub!(/^"(?=#{punct_class}\B)/, CLOSE_DBL_QUOTE)
# Special case for double sets of quotes, e.g.:
# <p>He said, "'Quoted' words in a larger quote."</p>
str.gsub!(/"'(?=\w)/, "#{OPEN_DBL_QUOTE}#{OPEN_SGL_QUOTE}")
str.gsub!(/'"(?=\w)/, "#{OPEN_SGL_QUOTE}#{OPEN_DBL_QUOTE}")
# Special case for decade abbreviations (the '80s):
str.gsub!(/'(?=\d\ds)/, CLOSE_SGL_QUOTE)
close_class = %![^\ \t\r\n\\[\{\(\-]!
dec_dashes = "#{EN_DASH}|#{EM_DASH}"#'–|—'
# Get most opening single quotes:
str.gsub!(/(\s| |--|&[mn]dash;|#{dec_dashes}|ȁ[34];)'(?=\w)/, '\1'+OPEN_SGL_QUOTE)
# Single closing quotes:
str.gsub!(/(#{close_class})'/, '\1'+CLOSE_SGL_QUOTE)
str.gsub!(/'(\s|s\b|$)/, CLOSE_SGL_QUOTE+'\1')
# Any remaining single quotes should be opening ones:
str.gsub!(/'/, OPEN_SGL_QUOTE)
# Get most opening double quotes:
str.gsub!(/(\s| |--|&[mn]dash;|#{dec_dashes}|ȁ[34];)"(?=\w)/,
'\1'+OPEN_DBL_QUOTE)
# Double closing quotes:
str.gsub!(/(#{close_class})"/, '\1'+CLOSE_DBL_QUOTE)
str.gsub!(/"(\s|s\b|$)/, CLOSE_DBL_QUOTE+'\1')
# Any remaining quotes should be opening ones:
str.gsub!(/"/, OPEN_DBL_QUOTE)
str
end
# Return the string, with each RubyPants HTML entity translated to
# its ASCII counterpart.
#
# Note: This is not reversible (but exactly the same as in SmartyPants)
#
def stupefy_entities(str)
str.
gsub(%r(#{EN_DASH}), "-"). # en-dash
gsub(%r(#{EM_DASH}), "--"). # em-dash
gsub(%r(#{OPEN_SGL_QUOTE}), "'"). # open single quote
gsub(%r(#{CLOSE_SGL_QUOTE}), "'"). # close single quote
gsub(%r(#{OPEN_DBL_QUOTE}), '"'). # open double quote
gsub(%r(#{CLOSE_DBL_QUOTE}), '"'). # close double quote
gsub(/…/, '...') # ellipsis
end
# Return an array of the tokens comprising the string. Each token is
# either a tag (possibly with nested, tags contained therein, such
# as <tt><a href="<MTFoo>"></tt>, or a run of text between
# tags. Each element of the array is a two-element array; the first
# is either :tag or :text; the second is the actual value.
#
# Based on the <tt>_tokenize()</tt> subroutine from Brad Choate's
# MTRegex plugin. <http://www.bradchoate.com/past/mtregex.php>
#
# This is actually the easier variant using tag_soup, as used by
# Chad Miller in the Python port of SmartyPants.
#
def tokenize(string)
tag_soup = /([^<]*)(<[^>]*>)/o
tokens = []
prev_end = 0
string.scan(tag_soup) {
tokens << [:text, $1] if $1 != ""
tokens << [:tag, $2]
prev_end = $~.end(0)
}
if prev_end < string.size
tokens << [:text, string[prev_end..-1]]
end
tokens
end
end
end