Class: RubyPants

# RubyPants (Class)

In: | rubypants.rb
Parent: | String

# 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 (`"` and `‘`) into "curly" quote HTML entities
- Backticks-style quotes (```like this’‘`) into "curly" quote HTML entities
- Dashes (`—` and `—`) into en- and em-dash entities
- Three consecutive dots (`…` or `. . .`) 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 `<pre>`, `<code>`, `<kbd>`, `<math>` or `<script>` 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 `6\’2\"` resp. `17\"`.)

## 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 ("`&8217;`") by hand.

## Bugs

To file bug reports or feature requests (except see above) please send email to: 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 © 2003 John Gruber (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: | daringfireball.net
SmartyPants: | daringfireball.net/projects/smartypants
Chad Miller: | web.chad.org
Christian Neukirchen: | kronavita.de/chris

## Methods

educate_backticks educate_dashes educate_dashes_inverted educate_dashes_oldschool educate_ellipses educate_quotes educate_single_backticks new process_escapes stupefy_entities to_html tokenize

## Constants

VERSION | = | "0.2"

## Public Class methods

new(string, options=[2])

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:

`:quotes` : | quotes
`:backticks` : | backtick quotes (``double’’ only)
`:allbackticks` : | backtick quotes (``double’’ and `single’)
`:dashes` : | dashes
`:oldschool` : | old school dashes
`:inverted` : | inverted old school dashes
`:ellipses` : | ellipses
`:convertquotes` : | convert `&quot;` entities to `"` for Dreamweaver users
`:stupefy` : | translate RubyPants HTML entities to their ASCII counterparts.

[Source]

         # File rubypants.rb, line 207
    207:   def initialize(string, options=[2])
    208:     super string
    209:     @options = [*options]
    210:   end

## Public Instance methods

to_html()

Apply SmartyPants transformations.

[Source]

         # File rubypants.rb, line 213
    213:   def to_html
    214:     do_quotes = do_backticks = do_dashes = do_ellipses = do_stupify = nil
    215:     convert_quotes = false
    216:
    217:     if @options.include? 0
    218:       # Do nothing.
    219:       return self
    220:     elsif @options.include? 1
    221:       # Do everything, turn all options on.
    222:       do_quotes = do_backticks = do_ellipses = true
    223:       do_dashes = :normal
    224:     elsif @options.include? 2
    225:       # Do everything, turn all options on, use old school dash shorthand.
    226:       do_quotes = do_backticks = do_ellipses = true
    227:       do_dashes = :oldschool
    228:     elsif @options.include? 3
    229:       # Do everything, turn all options on, use inverted old school
    230:       # dash shorthand.
    231:       do_quotes = do_backticks = do_ellipses = true
    232:       do_dashes = :inverted
    233:     elsif @options.include?(-1)
    234:       do_stupefy = true
    235:     else
    236:       do_quotes =                @options.include? :quotes
    237:       do_backticks =             @options.include? :backticks
    238:       do_backticks = :both    if @options.include? :allbackticks
    239:       do_dashes = :normal     if @options.include? :dashes
    240:       do_dashes = :oldschool  if @options.include? :oldschool
    241:       do_dashes = :inverted   if @options.include? :inverted
    242:       do_ellipses =              @options.include? :ellipses
    243:       convert_quotes =           @options.include? :convertquotes
    244:       do_stupefy =               @options.include? :stupefy
    245:     end
    246:
    247:     # Parse the HTML
    248:     tokens = tokenize
    249:
    250:     # Keep track of when we're inside <pre> or <code> tags.
    251:     in_pre = false
    252:
    253:     # Here is the result stored in.
    254:     result = ""
    255:
    256:     # This is a cheat, used to get some context for one-character
    257:     # tokens that consist of just a quote char. What we do is remember
    258:     # the last character of the previous text token, to use as context
    259:     # to curl single- character quote tokens correctly.
    260:     prev_token_last_char = nil
    261:
    262:     tokens.each { |token|
    263:       if token.first == :tag
    264:         result << token[1]
    265:         if token[1] =~ %!<(/?)(?:pre|code|kbd|script|math)[\s>]!
    266:           in_pre = ($1 != "/")  # Opening or closing tag?
    267:         end
    268:       else
    269:         t = token[1]
    270:
    271:         # Remember last char of this token before processing.
    272:         last_char = t[-1].chr
    273:
    274:         unless in_pre
    275:           t = process_escapes t
    276:
    277:           t.gsub!(/&quot;/, '"')  if convert_quotes
    278:
    279:           if do_dashes
    280:             t = educate_dashes t            if do_dashes == :normal
    281:             t = educate_dashes_oldschool t  if do_dashes == :oldschool
    282:             t = educate_dashes_inverted t   if do_dashes == :inverted
    283:           end
    284:
    285:           t = educate_ellipses t  if do_ellipses
    286:
    287:           # Note: backticks need to be processed before quotes.
    288:           if do_backticks
    289:             t = educate_backticks t
    290:             t = educate_single_backticks t  if do_backticks == :both
    291:           end
    292:
    293:           if do_quotes
    294:             if t == "'"
    295:               # Special case: single-character ' token
    296:               if prev_token_last_char =~ /\S/
    297:                 t = "&#8217;"
    298:               else
    299:                 t = "&#8216;"
    300:               end
    301:             elsif t == '"'
    302:               # Special case: single-character " token
    303:               if prev_token_last_char =~ /\S/
    304:                 t = "&#8221;"
    305:               else
    306:                 t = "&#8220;"
    307:               end
    308:             else
    309:               # Normal case:
    310:               t = educate_quotes t
    311:             end
    312:           end
    313:
    314:           t = stupefy_entities t  if do_stupefy
    315:         end
    316:
    317:         prev_token_last_char = last_char
    318:         result << t
    319:       end
    320:     }
    321:
    322:     # Done
    323:     result
    324:   end

## Protected Instance methods

educate_backticks(str)

Return the string, with "```backticks’‘`"-style single quotes translated into HTML curly quote entities.

[Source]

         # File rubypants.rb, line 384
    384:   def educate_backticks(str)
    385:     str.gsub("``", '&#8220;').gsub("''", '&#8221;')
    386:   end

educate_dashes(str)

The string, with each instance of "`—`" translated to an em-dash HTML entity.

[Source]

         # File rubypants.rb, line 347
    347:   def educate_dashes(str)
    348:     str.gsub(/--/, '&#8212;')
    349:   end

educate_dashes_inverted(str)

Return the string, with each instance of "`—`" translated to an em-dash HTML entity, and each "`—`" 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 "`—`" 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.)

[Source]

         # File rubypants.rb, line 369
    369:   def educate_dashes_inverted(str)
    370:     str.gsub(/---/, '&#8211;').gsub(/--/, '&#8212;')
    371:   end

educate_dashes_oldschool(str)

The string, with each instance of "`—`" translated to an en-dash HTML entity, and each "`—`" translated to an em-dash HTML entity.

[Source]

         # File rubypants.rb, line 355
    355:   def educate_dashes_oldschool(str)
    356:     str.gsub(/---/, '&#8212;').gsub(/--/, '&#8211;')
    357:   end

educate_ellipses(str)

Return the string, with each instance of "`…`" translated to an ellipsis HTML entity. Also converts the case where there are spaces between the dots.

[Source]

         # File rubypants.rb, line 377
    377:   def educate_ellipses(str)
    378:     str.gsub('...', '&#8230;').gsub('. . .', '&#8230;')
    379:   end

educate_quotes(str)

Return the string, with "educated" curly quote HTML entities.

[Source]

         # File rubypants.rb, line 397
    397:   def educate_quotes(str)
    398:     punct_class = '[!"#\$\%\'()*+,\-.\/:;<=>?\@\[\\\\\]\^^_`{|}~]'
    399:
    400:     str = str.dup
    401:
    402:     # Special case if the very first character is a quote followed by
    403:     # punctuation at a non-word-break. Close the quotes by brute
    404:     # force:
    405:     str.gsub!(/^'(?=#{punct_class}\B)/, '&#8217;')
    406:     str.gsub!(/^"(?=#{punct_class}\B)/, '&#8221;')
    407:
    408:     # Special case for double sets of quotes, e.g.:
    409:     #   <p>He said, "'Quoted' words in a larger quote."</p>
    410:     str.gsub!(/"'(?=\w)/, '&#8220;&#8216;')
    411:     str.gsub!(/'"(?=\w)/, '&#8216;&#8220;')
    412:
    413:     # Special case for decade abbreviations (the '80s):
    414:     str.gsub!(/'(?=\d\ds)/, '&#8217;')
    415:
    416:     close_class = %![^\ \t\r\n\\[\{\(\-]!
    417:     dec_dashes = '&#8211;|&#8212;'
    418:
    419:     # Get most opening single quotes:
    420:     str.gsub!(/(\s|&nbsp;|--|&[mn]dash;|#{dec_dashes}|&#x201[34];)'(?=\w)/,
    421:              '\1&#8216;')
    422:     # Single closing quotes:
    423:     str.gsub!(/(#{close_class})'/, '\1&#8217;')
    424:     str.gsub!(/'(\s|s\b|$)/, '&#8217;\1')
    425:     # Any remaining single quotes should be opening ones:
    426:     str.gsub!(/'/, '&#8216;')
    427:
    428:     # Get most opening double quotes:
    429:     str.gsub!(/(\s|&nbsp;|--|&[mn]dash;|#{dec_dashes}|&#x201[34];)"(?=\w)/,
    430:              '\1&#8220;')
    431:     # Double closing quotes:
    432:     str.gsub!(/(#{close_class})"/, '\1&#8221;')
    433:     str.gsub!(/"(\s|s\b|$)/, '&#8221;\1')
    434:     # Any remaining quotes should be opening ones:
    435:     str.gsub!(/"/, '&#8220;')
    436:
    437:     str
    438:   end

educate_single_backticks(str)

Return the string, with "``backticks’`"-style single quotes translated into HTML curly quote entities.

[Source]

         # File rubypants.rb, line 391
    391:   def educate_single_backticks(str)
    392:     str.gsub("`", '&#8216;').gsub("'", '&#8217;')
    393:   end

process_escapes(str)

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:

         \\    \"    \'    \.    \-    \`

[Source]

         # File rubypants.rb, line 335
    335:   def process_escapes(str)
    336:     str.gsub('\\\\', '&#92;').
    337:       gsub('\"', '&#34;').
    338:       gsub("\\\'", '&#39;').
    339:       gsub('\.', '&#46;').
    340:       gsub('\-', '&#45;').
    341:       gsub('\`', '&#96;')
    342:   end

stupefy_entities(str)

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)

[Source]

         # File rubypants.rb, line 445
    445:   def stupefy_entities(str)
    446:     str.
    447:       gsub(/&#8211;/, '-').      # en-dash
    448:       gsub(/&#8212;/, '--').     # em-dash
    449:
    450:       gsub(/&#8216;/, "'").      # open single quote
    451:       gsub(/&#8217;/, "'").      # close single quote
    452:
    453:       gsub(/&#8220;/, '"').      # open double quote
    454:       gsub(/&#8221;/, '"').      # close double quote
    455:
    456:       gsub(/&#8230;/, '...')     # ellipsis
    457:   end

tokenize()

Return an array of the tokens comprising the string. Each token is either a tag (possibly with nested, tags contained therein, such as `<a href="<MTFoo>">`, 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 `_tokenize()` subroutine from Brad Choate’s MTRegex plugin. <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.

[Source]

         # File rubypants.rb, line 471
    471:   def tokenize
    472:     tag_soup = /([^<]*)(<[^>]*>)/
    473:
    474:     tokens = []
    475:
    476:     prev_end = 0
    477:     scan(tag_soup) {
    478:       tokens << [:text, $1]  if $1 != ""
    479:       tokens << [:tag, $2]
    480:
    481:       prev_end = $~.end(0)
    482:     }
    483:
    484:     if prev_end < size
    485:       tokens << [:text, self[prev_end..-1]]
    486:     end
    487:
    488:     tokens
    489:   end

[Validate]