Class ActiveSupport::Multibyte::Chars
In: vendor/rails/activesupport/lib/active_support/multibyte/chars.rb
Parent: Object

Chars enables you to work transparently with UTF-8 encoding in the Ruby String class without having extensive knowledge about the encoding. A Chars object accepts a string upon initialization and proxies String methods in an encoding safe manner. All the normal String methods are also implemented on the proxy.

String methods are proxied through the Chars object, and can be accessed through the mb_chars method. Methods which would normally return a String object now return a Chars object so methods can be chained.

  "The Perfect String  ".mb_chars.downcase.strip.normalize #=> "the perfect string"

Chars objects are perfectly interchangeable with String objects as long as no explicit class checks are made. If certain methods do explicitly check the class, call to_s before you pass chars objects to them.

  bad.explicit_checking_method "T".mb_chars.downcase.to_s

The default Chars implementation assumes that the encoding of the string is UTF-8, if you want to handle different encodings you can write your own multibyte string handler and configure it through ActiveSupport::Multibyte.proxy_class.

  class CharsForUTF32
    def size
      @wrapped_string.size / 4
    end

    def self.accepts?(string)
      string.length % 4 == 0
    end
  end

  ActiveSupport::Multibyte.proxy_class = CharsForUTF32

Methods

Included Modules

Comparable

Constants

HANGUL_SBASE = 0xAC00   Hangul character boundaries and properties
HANGUL_LBASE = 0x1100
HANGUL_VBASE = 0x1161
HANGUL_TBASE = 0x11A7
HANGUL_LCOUNT = 19
HANGUL_VCOUNT = 21
HANGUL_TCOUNT = 28
HANGUL_NCOUNT = HANGUL_VCOUNT * HANGUL_TCOUNT
HANGUL_SCOUNT = 11172
HANGUL_SLAST = HANGUL_SBASE + HANGUL_SCOUNT
HANGUL_JAMO_FIRST = 0x1100
HANGUL_JAMO_LAST = 0x11FF
UNICODE_WHITESPACE = [ (0x0009..0x000D).to_a, # White_Space # Cc [5] <control-0009>..<control-000D> 0x0020, # White_Space # Zs SPACE 0x0085, # White_Space # Cc <control-0085> 0x00A0, # White_Space # Zs NO-BREAK SPACE 0x1680, # White_Space # Zs OGHAM SPACE MARK 0x180E, # White_Space # Zs MONGOLIAN VOWEL SEPARATOR (0x2000..0x200A).to_a, # White_Space # Zs [11] EN QUAD..HAIR SPACE 0x2028, # White_Space # Zl LINE SEPARATOR 0x2029, # White_Space # Zp PARAGRAPH SEPARATOR 0x202F, # White_Space # Zs NARROW NO-BREAK SPACE 0x205F, # White_Space # Zs MEDIUM MATHEMATICAL SPACE 0x3000, # White_Space # Zs IDEOGRAPHIC SPACE ].flatten.freeze   All the unicode whitespace
UNICODE_LEADERS_AND_TRAILERS = UNICODE_WHITESPACE + [65279]   BOM (byte order mark) can also be seen as whitespace, it‘s a non-rendering character used to distinguish between little and big endian. This is not an issue in utf-8, so it must be ignored.
UNICODE_TRAILERS_PAT = /(#{codepoints_to_pattern(UNICODE_LEADERS_AND_TRAILERS)})+\Z/
UNICODE_LEADERS_PAT = /\A(#{codepoints_to_pattern(UNICODE_LEADERS_AND_TRAILERS)})+/
UTF8_PAT = ActiveSupport::Multibyte::VALID_CHARACTER['UTF-8']

External Aliases

wrapped_string -> to_s
wrapped_string -> to_str

Attributes

wrapped_string  [R] 

Public Class methods

Compose decomposed characters to the composed form.

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 550
550:         def compose_codepoints(codepoints)
551:           pos = 0
552:           eoa = codepoints.length - 1
553:           starter_pos = 0
554:           starter_char = codepoints[0]
555:           previous_combining_class = -1
556:           while pos < eoa
557:             pos += 1
558:             lindex = starter_char - HANGUL_LBASE
559:             # -- Hangul
560:             if 0 <= lindex and lindex < HANGUL_LCOUNT
561:               vindex = codepoints[starter_pos+1] - HANGUL_VBASE rescue vindex = -1
562:               if 0 <= vindex and vindex < HANGUL_VCOUNT
563:                 tindex = codepoints[starter_pos+2] - HANGUL_TBASE rescue tindex = -1
564:                 if 0 <= tindex and tindex < HANGUL_TCOUNT
565:                   j = starter_pos + 2
566:                   eoa -= 2
567:                 else
568:                   tindex = 0
569:                   j = starter_pos + 1
570:                   eoa -= 1
571:                 end
572:                 codepoints[starter_pos..j] = (lindex * HANGUL_VCOUNT + vindex) * HANGUL_TCOUNT + tindex + HANGUL_SBASE
573:               end
574:               starter_pos += 1
575:               starter_char = codepoints[starter_pos]
576:             # -- Other characters
577:             else
578:               current_char = codepoints[pos]
579:               current = UCD.codepoints[current_char]
580:               if current.combining_class > previous_combining_class
581:                 if ref = UCD.composition_map[starter_char]
582:                   composition = ref[current_char]
583:                 else
584:                   composition = nil
585:                 end
586:                 unless composition.nil?
587:                   codepoints[starter_pos] = composition
588:                   starter_char = composition
589:                   codepoints.delete_at pos
590:                   eoa -= 1
591:                   pos -= 1
592:                   previous_combining_class = -1
593:                 else
594:                   previous_combining_class = current.combining_class
595:                 end
596:               else
597:                 previous_combining_class = current.combining_class
598:               end
599:               if current.combining_class == 0
600:                 starter_pos = pos
601:                 starter_char = codepoints[pos]
602:               end
603:             end
604:           end
605:           codepoints
606:         end

Returns true when the proxy class can handle the string. Returns false otherwise.

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 123
123:       def self.consumes?(string)
124:         # Unpack is a little bit faster than regular expressions.
125:         string.unpack('U*')
126:         true
127:       rescue ArgumentError
128:         false
129:       end

Decompose composed characters to the decomposed form.

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 529
529:         def decompose_codepoints(type, codepoints)
530:           codepoints.inject([]) do |decomposed, cp|
531:             # if it's a hangul syllable starter character
532:             if HANGUL_SBASE <= cp and cp < HANGUL_SLAST
533:               sindex = cp - HANGUL_SBASE
534:               ncp = [] # new codepoints
535:               ncp << HANGUL_LBASE + sindex / HANGUL_NCOUNT
536:               ncp << HANGUL_VBASE + (sindex % HANGUL_NCOUNT) / HANGUL_TCOUNT
537:               tindex = sindex % HANGUL_TCOUNT
538:               ncp << (HANGUL_TBASE + tindex) unless tindex == 0
539:               decomposed.concat ncp
540:             # if the codepoint is decomposable in with the current decomposition type
541:             elsif (ncp = UCD.codepoints[cp].decomp_mapping) and (!UCD.codepoints[cp].decomp_type || type == :compatability)
542:               decomposed.concat decompose_codepoints(type, ncp.dup)
543:             else
544:               decomposed << cp
545:             end
546:           end
547:         end

Reverse operation of g_unpack.

Example:

  Chars.g_pack(Chars.g_unpack('क्षि')) #=> 'क्षि'

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 500
500:         def g_pack(unpacked)
501:           (unpacked.flatten).pack('U*')
502:         end

Unpack the string at grapheme boundaries. Returns a list of character lists.

Example:

  Chars.g_unpack('क्षि') #=> [[2325, 2381], [2359], [2367]]
  Chars.g_unpack('Café') #=> [[67], [97], [102], [233]]

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 466
466:         def g_unpack(string)
467:           codepoints = u_unpack(string)
468:           unpacked = []
469:           pos = 0
470:           marker = 0
471:           eoc = codepoints.length
472:           while(pos < eoc)
473:             pos += 1
474:             previous = codepoints[pos-1]
475:             current = codepoints[pos]
476:             if (
477:                 # CR X LF
478:                 one = ( previous == UCD.boundary[:cr] and current == UCD.boundary[:lf] ) or
479:                 # L X (L|V|LV|LVT)
480:                 two = ( UCD.boundary[:l] === previous and in_char_class?(current, [:l,:v,:lv,:lvt]) ) or
481:                 # (LV|V) X (V|T)
482:                 three = ( in_char_class?(previous, [:lv,:v]) and in_char_class?(current, [:v,:t]) ) or
483:                 # (LVT|T) X (T)
484:                 four = ( in_char_class?(previous, [:lvt,:t]) and UCD.boundary[:t] === current ) or
485:                 # X Extend
486:                 five = (UCD.boundary[:extend] === current)
487:               )
488:             else
489:               unpacked << codepoints[marker..pos-1]
490:               marker = pos
491:             end
492:           end 
493:           unpacked
494:         end

Detect whether the codepoint is in a certain character class. Returns true when it‘s in the specified character class and false otherwise. Valid character classes are: :cr, :lf, :l, :v, :lv, :lvt and :t.

Primarily used by the grapheme cluster support.

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 457
457:         def in_char_class?(codepoint, classes)
458:           classes.detect { |c| UCD.boundary[c] === codepoint } ? true : false
459:         end

Creates a new Chars instance by wrapping string.

[Source]

    # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 84
84:         def initialize(string)
85:           @wrapped_string = string
86:           @wrapped_string.force_encoding(Encoding::UTF_8) unless @wrapped_string.frozen?
87:         end

Re-order codepoints so the string becomes canonical.

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 513
513:         def reorder_characters(codepoints)
514:           length = codepoints.length- 1
515:           pos = 0
516:           while pos < length do
517:             cp1, cp2 = UCD.codepoints[codepoints[pos]], UCD.codepoints[codepoints[pos+1]]
518:             if (cp1.combining_class > cp2.combining_class) && (cp2.combining_class > 0)
519:               codepoints[pos..pos+1] = cp2.code, cp1.code
520:               pos += (pos > 0 ? -1 : 1)
521:             else
522:               pos += 1
523:             end
524:           end
525:           codepoints
526:         end

Replaces all ISO-8859-1 or CP1252 characters by their UTF-8 equivalent resulting in a valid UTF-8 string.

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 609
609:         def tidy_bytes(string)
610:           string.split(//u).map do |c|
611:             c.force_encoding(Encoding::ASCII) if c.respond_to?(:force_encoding)
612: 
613:             if !ActiveSupport::Multibyte::VALID_CHARACTER['UTF-8'].match(c)
614:               n = c.unpack('C')[0]
615:               n < 128 ? n.chr :
616:               n < 160 ? [UCD.cp1252[n] || n].pack('U') :
617:               n < 192 ? "\xC2" + n.chr : "\xC3" + (n-64).chr
618:             else
619:               c
620:             end
621:           end.join
622:         end

Unpack the string at codepoints boundaries. Raises an EncodingError when the encoding of the string isn‘t valid UTF-8.

Example:

  Chars.u_unpack('Café') #=> [67, 97, 102, 233]

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 444
444:         def u_unpack(string)
445:           begin
446:             string.unpack 'U*'
447:           rescue ArgumentError
448:             raise EncodingError, 'malformed UTF-8 character'
449:           end
450:         end

Returns true if the Chars class can and should act as a proxy for the string string. Returns false otherwise.

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 118
118:       def self.wants?(string)
119:         $KCODE == 'UTF8' && consumes?(string)
120:       end

Public Instance methods

Returns a new Chars object containing the other object concatenated to the string.

Example:

  ('Café'.mb_chars + ' périferôl').to_s #=> "Café périferôl"

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 147
147:       def +(other)
148:         self << other
149:       end

Returns -1, 0 or +1 depending on whether the Chars object is to be sorted before, equal or after the object on the right side of the operation. It accepts any object that implements to_s. See String#<=> for more details.

Example:

  'é'.mb_chars <=> 'ü'.mb_chars #=> -1

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 139
139:       def <=>(other)
140:         @wrapped_string <=> other.to_s
141:       end

Like String#=~ only it returns the character offset (in codepoints) instead of the byte offset.

Example:

  'Café périferôl'.mb_chars =~ /ô/ #=> 12

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 155
155:       def =~(other)
156:         translate_offset(@wrapped_string =~ other)
157:       end
[](*args)

Alias for slice

Like String#[]=, except instead of byte offsets you specify character offsets.

Example:

  s = "Müller"
  s.mb_chars[2] = "e" # Replace character with offset 2
  s
  #=> "Müeler"

  s = "Müller"
  s.mb_chars[1, 2] = "ö" # Replace 2 characters at character offset 1
  s
  #=> "Möler"

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 216
216:       def []=(*args)
217:         replace_by = args.pop
218:         # Indexed replace with regular expressions already works
219:         if args.first.is_a?(Regexp)
220:           @wrapped_string[*args] = replace_by
221:         else
222:           result = self.class.u_unpack(@wrapped_string)
223:           if args[0].is_a?(Fixnum)
224:             raise IndexError, "index #{args[0]} out of string" if args[0] >= result.length
225:             min = args[0]
226:             max = args[1].nil? ? min : (min + args[1] - 1)
227:             range = Range.new(min, max)
228:             replace_by = [replace_by].pack('U') if replace_by.is_a?(Fixnum)
229:           elsif args.first.is_a?(Range)
230:             raise RangeError, "#{args[0]} out of range" if args[0].min >= result.length
231:             range = args[0]
232:           else
233:             needle = args[0].to_s
234:             min = index(needle)
235:             max = min + self.class.u_unpack(needle).length - 1
236:             range = Range.new(min, max)
237:           end
238:           result[range] = self.class.u_unpack(replace_by)
239:           @wrapped_string.replace(result.pack('U*'))
240:         end
241:       end

Enable more predictable duck-typing on String-like classes. See Object#acts_like?.

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 112
112:       def acts_like_string?
113:         true
114:       end

Converts the first character to uppercase and the remainder to lowercase.

Example:

 'über'.mb_chars.capitalize.to_s #=> "Über"

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 366
366:       def capitalize
367:         (slice(0) || chars('')).upcase + (slice(1..-1) || chars('')).downcase
368:       end

Works just like String#center, only integer specifies characters instead of bytes.

Example:

  "¾ cup".mb_chars.center(8).to_s
  #=> " ¾ cup  "

  "¾ cup".mb_chars.center(8, " ").to_s # Use non-breaking whitespace
  #=> " ¾ cup  "

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 278
278:       def center(integer, padstr=' ')
279:         justify(integer, :center, padstr)
280:       end

Performs composition on all the characters.

Example:

  'é'.length #=> 3
  'é'.mb_chars.compose.to_s.length #=> 2

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 408
408:       def compose
409:         chars(self.class.compose_codepoints(self.class.u_unpack(@wrapped_string)).pack('U*'))
410:       end

Performs canonical decomposition on all the characters.

Example:

  'é'.length #=> 2
  'é'.mb_chars.decompose.to_s.length #=> 3

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 399
399:       def decompose
400:         chars(self.class.decompose_codepoints(:canonical, self.class.u_unpack(@wrapped_string)).pack('U*'))
401:       end

Convert characters in the string to lowercase.

Example:

  'VĚDA A VÝZKUM'.mb_chars.downcase.to_s #=> "věda a výzkum"

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 358
358:       def downcase
359:         apply_mapping :lowercase_mapping
360:       end

Returns the number of grapheme clusters in the string.

Example:

  'क्षि'.mb_chars.length #=> 4
  'क्षि'.mb_chars.g_length #=> 3

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 417
417:       def g_length
418:         self.class.g_unpack(@wrapped_string).length
419:       end

Returns true if contained string contains other. Returns false otherwise.

Example:

  'Café'.mb_chars.include?('é') #=> true

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 188
188:       def include?(other)
189:         # We have to redefine this method because Enumerable defines it.
190:         @wrapped_string.include?(other)
191:       end

Returns the position needle in the string, counting in codepoints. Returns nil if needle isn‘t found.

Example:

  'Café périferôl'.mb_chars.index('ô') #=> 12
  'Café périferôl'.mb_chars.index(/\w/u) #=> 0

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 198
198:       def index(needle, offset=0)
199:         index = @wrapped_string.index(needle, offset)
200:         index ? (self.class.u_unpack(@wrapped_string.slice(0...index)).size) : nil
201:       end

Inserts the passed string at specified codepoint offsets.

Example:

  'Café'.mb_chars.insert(4, ' périferôl').to_s #=> "Café périferôl"

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 172
172:       def insert(offset, fragment)
173:         unpacked = self.class.u_unpack(@wrapped_string)
174:         unless offset > unpacked.length
175:           @wrapped_string.replace(
176:             self.class.u_unpack(@wrapped_string).insert(offset, *self.class.u_unpack(fragment)).pack('U*')
177:           )
178:         else
179:           raise IndexError, "index #{offset} out of string"
180:         end
181:         self
182:       end
length()

Alias for size

Works just like String#ljust, only integer specifies characters instead of bytes.

Example:

  "¾ cup".mb_chars.rjust(8).to_s
  #=> "¾ cup   "

  "¾ cup".mb_chars.rjust(8, " ").to_s # Use non-breaking whitespace
  #=> "¾ cup   "

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 265
265:       def ljust(integer, padstr=' ')
266:         justify(integer, :left, padstr)
267:       end

Strips entire range of Unicode whitespace from the left of the string.

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 288
288:       def lstrip
289:         chars(@wrapped_string.gsub(UNICODE_LEADERS_PAT, ''))
290:       end

Forward all undefined methods to the wrapped string.

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 95
 95:       def method_missing(method, *args, &block)
 96:         if method.to_s =~ /!$/
 97:           @wrapped_string.__send__(method, *args, &block)
 98:           self
 99:         else
100:           result = @wrapped_string.__send__(method, *args, &block)
101:           result.kind_of?(String) ? chars(result) : result
102:         end
103:       end

Returns the KC normalization of the string by default. NFKC is considered the best normalization form for passing strings to databases and validations.

  • str - The string to perform normalization on.
  • form - The form you want to normalize in. Should be one of the following: :c, :kc, :d, or :kd. Default is ActiveSupport::Multibyte.default_normalization_form

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 377
377:       def normalize(form=ActiveSupport::Multibyte.default_normalization_form)
378:         # See http://www.unicode.org/reports/tr15, Table 1
379:         codepoints = self.class.u_unpack(@wrapped_string)
380:         chars(case form
381:           when :d
382:             self.class.reorder_characters(self.class.decompose_codepoints(:canonical, codepoints))
383:           when :c
384:             self.class.compose_codepoints(self.class.reorder_characters(self.class.decompose_codepoints(:canonical, codepoints)))
385:           when :kd
386:             self.class.reorder_characters(self.class.decompose_codepoints(:compatability, codepoints))
387:           when :kc
388:             self.class.compose_codepoints(self.class.reorder_characters(self.class.decompose_codepoints(:compatability, codepoints)))
389:           else
390:             raise ArgumentError, "#{form} is not a valid normalization variant", caller
391:         end.pack('U*'))
392:       end

Converts first character in the string to Unicode value

Example:

  'こんにちは'.mb_chars.ord #=> 12371

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 342
342:       def ord
343:         self.class.u_unpack(@wrapped_string)[0]
344:       end

Returns true if obj responds to the given method. Private methods are included in the search only if the optional second parameter evaluates to true.

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 107
107:       def respond_to?(method, include_private=false)
108:         super || @wrapped_string.respond_to?(method, include_private) || false
109:       end

Reverses all characters in the string.

Example:

  'Café'.mb_chars.reverse.to_s #=> 'éfaC'

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 307
307:       def reverse
308:         chars(self.class.u_unpack(@wrapped_string).reverse.pack('U*'))
309:       end

Works just like String#rjust, only integer specifies characters instead of bytes.

Example:

  "¾ cup".mb_chars.rjust(8).to_s
  #=> "   ¾ cup"

  "¾ cup".mb_chars.rjust(8, " ").to_s # Use non-breaking whitespace
  #=> "   ¾ cup"

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 252
252:       def rjust(integer, padstr=' ')
253:         justify(integer, :right, padstr)
254:       end

Strips entire range of Unicode whitespace from the right of the string.

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 283
283:       def rstrip
284:         chars(@wrapped_string.gsub(UNICODE_TRAILERS_PAT, ''))
285:       end

Returns the number of codepoints in the string

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 298
298:       def size
299:         self.class.u_unpack(@wrapped_string).size
300:       end

Implements Unicode-aware slice with codepoints. Slicing on one point returns the codepoints for that character.

Example:

  'こんにちは'.mb_chars.slice(2..3).to_s #=> "にち"

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 316
316:       def slice(*args)
317:         if args.size > 2
318:           raise ArgumentError, "wrong number of arguments (#{args.size} for 1)" # Do as if we were native
319:         elsif (args.size == 2 && !(args.first.is_a?(Numeric) || args.first.is_a?(Regexp)))
320:           raise TypeError, "cannot convert #{args.first.class} into Integer" # Do as if we were native
321:         elsif (args.size == 2 && !args[1].is_a?(Numeric))
322:           raise TypeError, "cannot convert #{args[1].class} into Integer" # Do as if we were native
323:         elsif args[0].kind_of? Range
324:           cps = self.class.u_unpack(@wrapped_string).slice(*args)
325:           result = cps.nil? ? nil : cps.pack('U*')
326:         elsif args[0].kind_of? Regexp
327:           result = @wrapped_string.slice(*args)
328:         elsif args.size == 1 && args[0].kind_of?(Numeric)
329:           character = self.class.u_unpack(@wrapped_string)[args[0]]
330:           result = character.nil? ? nil : [character].pack('U')
331:         else
332:           result = self.class.u_unpack(@wrapped_string).slice(*args).pack('U*')
333:         end
334:         result.nil? ? nil : chars(result)
335:       end

Works just like String#split, with the exception that the items in the resulting list are Chars instances instead of String. This makes chaining methods easier.

Example:

  'Café périferôl'.mb_chars.split(/é/).map { |part| part.upcase.to_s } #=> ["CAF", " P", "RIFERÔL"]

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 164
164:       def split(*args)
165:         @wrapped_string.split(*args).map { |i| i.mb_chars }
166:       end

Strips entire range of Unicode whitespace from the right and left of the string.

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 293
293:       def strip
294:         rstrip.lstrip
295:       end

Replaces all ISO-8859-1 or CP1252 characters by their UTF-8 equivalent resulting in a valid UTF-8 string.

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 422
422:       def tidy_bytes
423:         chars(self.class.tidy_bytes(@wrapped_string))
424:       end

Convert characters in the string to uppercase.

Example:

  'Laurent, òu sont les tests?'.mb_chars.upcase.to_s #=> "LAURENT, ÒU SONT LES TESTS?"

[Source]

     # File vendor/rails/activesupport/lib/active_support/multibyte/chars.rb, line 350
350:       def upcase
351:         apply_mapping :uppercase_mapping
352:       end

[Validate]