Class: ActiveSupport::Multibyte::Chars

Inherits:
Object
  • Object
show all
Includes:
Comparable
Defined in:
lib/active_support/multibyte/chars.rb

Overview

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

Constant Summary collapse

HANGUL_SBASE =

Hangul character boundaries and properties

0xAC00
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 =

All the 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
UNICODE_LEADERS_AND_TRAILERS =

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_WHITESPACE + [65279]
UNICODE_TRAILERS_PAT = 
/(#{codepoints_to_pattern(UNICODE_LEADERS_AND_TRAILERS)})+\Z/
UNICODE_LEADERS_PAT = 
/\A(#{codepoints_to_pattern(UNICODE_LEADERS_AND_TRAILERS)})+/
UTF8_PAT = 




Instance Attribute Summary collapse




Class Method Summary
collapse





Instance Method Summary
collapse






Constructor Details





#initialize(string) ⇒ Chars







:nodoc:















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# File 'lib/active_support/multibyte/chars.rb', line 84

def initialize(string)
  @wrapped_string = string
  @wrapped_string.force_encoding(Encoding::UTF_8) unless @wrapped_string.frozen?
end













Dynamic Method Handling



This class handles dynamic methods through the method_missing method






#method_missing(method, *args, &block) ⇒ Object







Forward all undefined methods to the wrapped string.















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# File 'lib/active_support/multibyte/chars.rb', line 95

def method_missing(method, *args, &block)
  if method.to_s =~ /!$/
    @wrapped_string.__send__(method, *args, &block)
    self
  else
    result = @wrapped_string.__send__(method, *args, &block)
    result.kind_of?(String) ? chars(result) : result
  end
end













Instance Attribute Details






#wrapped_string ⇒ Object (readonly)
Also known as:
to_s, to_str








Returns the value of attribute wrapped_string.















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# File 'lib/active_support/multibyte/chars.rb', line 78

def wrapped_string
  @wrapped_string
end













Class Method Details





.codepoints_to_pattern(array_of_codepoints) ⇒ Object







Returns a regular expression pattern that matches the passed Unicode codepoints















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# File 'lib/active_support/multibyte/chars.rb', line 70

def self.codepoints_to_pattern(array_of_codepoints) #:nodoc:
  array_of_codepoints.collect{ |e| [e].pack 'U*' }.join('|')
end












.compose_codepoints(codepoints) ⇒ Object







Compose decomposed characters to the composed form.















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# File 'lib/active_support/multibyte/chars.rb', line 577

def compose_codepoints(codepoints)
  pos = 0
  eoa = codepoints.length - 1
  starter_pos = 0
  starter_char = codepoints[0]
  previous_combining_class = -1
  while pos < eoa
    pos += 1
    lindex = starter_char - HANGUL_LBASE
    # -- Hangul
    if 0 <= lindex and lindex < HANGUL_LCOUNT
      vindex = codepoints[starter_pos+1] - HANGUL_VBASE rescue vindex = -1
      if 0 <= vindex and vindex < HANGUL_VCOUNT
        tindex = codepoints[starter_pos+2] - HANGUL_TBASE rescue tindex = -1
        if 0 <= tindex and tindex < HANGUL_TCOUNT
          j = starter_pos + 2
          eoa -= 2
        else
          tindex = 0
          j = starter_pos + 1
          eoa -= 1
        end
        codepoints[starter_pos..j] = (lindex * HANGUL_VCOUNT + vindex) * HANGUL_TCOUNT + tindex + HANGUL_SBASE
      end
      starter_pos += 1
      starter_char = codepoints[starter_pos]
    # -- Other characters
    else
      current_char = codepoints[pos]
      current = UCD.codepoints[current_char]
      if current.combining_class > previous_combining_class
        if ref = UCD.composition_map[starter_char]
          composition = ref[current_char]
        else
          composition = nil
        end
        unless composition.nil?
          codepoints[starter_pos] = composition
          starter_char = composition
          codepoints.delete_at pos
          eoa -= 1
          pos -= 1
          previous_combining_class = -1
        else
          previous_combining_class = current.combining_class
        end
      else
        previous_combining_class = current.combining_class
      end
      if current.combining_class == 0
        starter_pos = pos
        starter_char = codepoints[pos]
      end
    end
  end
  codepoints
end












.consumes?(string) ⇒ Boolean







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








Returns:


    

  • 
(Boolean)

    • 










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# File 'lib/active_support/multibyte/chars.rb', line 123

def self.consumes?(string)
  # Unpack is a little bit faster than regular expressions.
  string.unpack('U*')
  true
rescue ArgumentError
  false
end












.decompose_codepoints(type, codepoints) ⇒ Object







Decompose composed characters to the decomposed form.















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# File 'lib/active_support/multibyte/chars.rb', line 556

def decompose_codepoints(type, codepoints)
  codepoints.inject([]) do |decomposed, cp|
    # if it's a hangul syllable starter character
    if HANGUL_SBASE <= cp and cp < HANGUL_SLAST
      sindex = cp - HANGUL_SBASE
      ncp = [] # new codepoints
      ncp << HANGUL_LBASE + sindex / HANGUL_NCOUNT
      ncp << HANGUL_VBASE + (sindex % HANGUL_NCOUNT) / HANGUL_TCOUNT
      tindex = sindex % HANGUL_TCOUNT
      ncp << (HANGUL_TBASE + tindex) unless tindex == 0
      decomposed.concat ncp
    # if the codepoint is decomposable in with the current decomposition type
    elsif (ncp = UCD.codepoints[cp].decomp_mapping) and (!UCD.codepoints[cp].decomp_type || type == :compatability)
      decomposed.concat decompose_codepoints(type, ncp.dup)
    else
      decomposed << cp
    end
  end
end












.g_pack(unpacked) ⇒ Object







Reverse operation of g_unpack.


Example:


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
















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# File 'lib/active_support/multibyte/chars.rb', line 527

def g_pack(unpacked)
  (unpacked.flatten).pack('U*')
end












.g_unpack(string) ⇒ Object







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]]
















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# File 'lib/active_support/multibyte/chars.rb', line 493

def g_unpack(string)
  codepoints = u_unpack(string)
  unpacked = []
  pos = 0
  marker = 0
  eoc = codepoints.length
  while(pos < eoc)
    pos += 1
    previous = codepoints[pos-1]
    current = codepoints[pos]
    if (
        # CR X LF
        one = ( previous == UCD.boundary[:cr] and current == UCD.boundary[:lf] ) or
        # L X (L|V|LV|LVT)
        two = ( UCD.boundary[:l] === previous and in_char_class?(current, [:l,:v,:lv,:lvt]) ) or
        # (LV|V) X (V|T)
        three = ( in_char_class?(previous, [:lv,:v]) and in_char_class?(current, [:v,:t]) ) or
        # (LVT|T) X (T)
        four = ( in_char_class?(previous, [:lvt,:t]) and UCD.boundary[:t] === current ) or
        # X Extend
        five = (UCD.boundary[:extend] === current)
      )
    else
      unpacked << codepoints[marker..pos-1]
      marker = pos
    end
  end 
  unpacked
end












.in_char_class?(codepoint, classes) ⇒ Boolean







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.








Returns:


    

  • 
(Boolean)

    • 










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# File 'lib/active_support/multibyte/chars.rb', line 484

def in_char_class?(codepoint, classes)
  classes.detect { |c| UCD.boundary[c] === codepoint } ? true : false
end












.padding(padsize, padstr = ' ') ⇒ Object







:nodoc:















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# File 'lib/active_support/multibyte/chars.rb', line 531

def padding(padsize, padstr=' ') #:nodoc:
  if padsize != 0
    new(padstr * ((padsize / u_unpack(padstr).size) + 1)).slice(0, padsize)
  else
    ''
  end
end












.reorder_characters(codepoints) ⇒ Object







Re-order codepoints so the string becomes canonical.















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# File 'lib/active_support/multibyte/chars.rb', line 540

def reorder_characters(codepoints)
  length = codepoints.length- 1
  pos = 0
  while pos < length do
    cp1, cp2 = UCD.codepoints[codepoints[pos]], UCD.codepoints[codepoints[pos+1]]
    if (cp1.combining_class > cp2.combining_class) && (cp2.combining_class > 0)
      codepoints[pos..pos+1] = cp2.code, cp1.code
      pos += (pos > 0 ? -1 : 1)
    else
      pos += 1
    end
  end
  codepoints
end












.tidy_bytes(string) ⇒ Object







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















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# File 'lib/active_support/multibyte/chars.rb', line 636

def tidy_bytes(string)
  string.split(//u).map do |c|
    c.force_encoding(Encoding::ASCII) if c.respond_to?(:force_encoding)

    if !ActiveSupport::Multibyte::VALID_CHARACTER['UTF-8'].match(c)
      n = c.unpack('C')[0]
      n < 128 ? n.chr :
      n < 160 ? [UCD.cp1252[n] || n].pack('U') :
      n < 192 ? "\xC2" + n.chr : "\xC3" + (n-64).chr
    else
      c
    end
  end.join
end












.u_unpack(string) ⇒ Object







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]
















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# File 'lib/active_support/multibyte/chars.rb', line 471

def u_unpack(string)
  begin
    string.unpack 'U*'
  rescue ArgumentError
    raise EncodingError, 'malformed UTF-8 character'
  end
end












.wants?(string) ⇒ Boolean







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








Returns:


    

  • 
(Boolean)

    • 










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# File 'lib/active_support/multibyte/chars.rb', line 118

def self.wants?(string)
  $KCODE == 'UTF8' && consumes?(string)
end













Instance Method Details





#+(other) ⇒ Object







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


Example:


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
















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# File 'lib/active_support/multibyte/chars.rb', line 147

def +(other)
  self << other
end












#<=>(other) ⇒ Object







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
















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# File 'lib/active_support/multibyte/chars.rb', line 139

def <=>(other)
  @wrapped_string <=> other.to_s
end












#=~(other) ⇒ Object







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


Example:


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
















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# File 'lib/active_support/multibyte/chars.rb', line 155

def =~(other)
  translate_offset(@wrapped_string =~ other)
end












#[]=(*args) ⇒ Object







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"
















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# File 'lib/active_support/multibyte/chars.rb', line 231

def []=(*args)
  replace_by = args.pop
  # Indexed replace with regular expressions already works
  if args.first.is_a?(Regexp)
    @wrapped_string[*args] = replace_by
  else
    result = self.class.u_unpack(@wrapped_string)
    if args[0].is_a?(Fixnum)
      raise IndexError, "index #{args[0]} out of string" if args[0] >= result.length
      min = args[0]
      max = args[1].nil? ? min : (min + args[1] - 1)
      range = Range.new(min, max)
      replace_by = [replace_by].pack('U') if replace_by.is_a?(Fixnum)
    elsif args.first.is_a?(Range)
      raise RangeError, "#{args[0]} out of range" if args[0].min >= result.length
      range = args[0]
    else
      needle = args[0].to_s
      min = index(needle)
      max = min + self.class.u_unpack(needle).length - 1
      range = Range.new(min, max)
    end
    result[range] = self.class.u_unpack(replace_by)
    @wrapped_string.replace(result.pack('U*'))
  end
end












#acts_like_string? ⇒ Boolean







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








Returns:


    

  • 
(Boolean)

    • 










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# File 'lib/active_support/multibyte/chars.rb', line 112

def acts_like_string?
  true
end












#capitalize ⇒ Object







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


Example:


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
















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# File 'lib/active_support/multibyte/chars.rb', line 393

def capitalize
  (slice(0) || chars('')).upcase + (slice(1..-1) || chars('')).downcase
end












#center(integer, padstr = ' ') ⇒ Object







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  "
















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# File 'lib/active_support/multibyte/chars.rb', line 293

def center(integer, padstr=' ')
  justify(integer, :center, padstr)
end












#compose ⇒ Object







Performs composition on all the characters.


Example:


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
















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# File 'lib/active_support/multibyte/chars.rb', line 435

def compose
  chars(self.class.compose_codepoints(self.class.u_unpack(@wrapped_string)).pack('U*'))
end












#decompose ⇒ Object







Performs canonical decomposition on all the characters.


Example:


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
















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# File 'lib/active_support/multibyte/chars.rb', line 426

def decompose
  chars(self.class.decompose_codepoints(:canonical, self.class.u_unpack(@wrapped_string)).pack('U*'))
end












#downcase ⇒ Object







Convert characters in the string to lowercase.


Example:


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
















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# File 'lib/active_support/multibyte/chars.rb', line 385

def downcase
  apply_mapping :lowercase_mapping
end












#g_length ⇒ Object







Returns the number of grapheme clusters in the string.


Example:


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
















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# File 'lib/active_support/multibyte/chars.rb', line 444

def g_length
  self.class.g_unpack(@wrapped_string).length
end












#include?(other) ⇒ Boolean







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


Example:


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









Returns:


    

  • 
(Boolean)

    • 










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# File 'lib/active_support/multibyte/chars.rb', line 188

def include?(other)
  # We have to redefine this method because Enumerable defines it.
  @wrapped_string.include?(other)
end












#index(needle, offset = 0) ⇒ Object







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
















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# File 'lib/active_support/multibyte/chars.rb', line 198

def index(needle, offset=0)
  wrapped_offset = self.first(offset).wrapped_string.length
  index = @wrapped_string.index(needle, wrapped_offset)
  index ? (self.class.u_unpack(@wrapped_string.slice(0...index)).size) : nil
end












#insert(offset, fragment) ⇒ Object







Inserts the passed string at specified codepoint offsets.


Example:


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
















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# File 'lib/active_support/multibyte/chars.rb', line 172

def insert(offset, fragment)
  unpacked = self.class.u_unpack(@wrapped_string)
  unless offset > unpacked.length
    @wrapped_string.replace(
      self.class.u_unpack(@wrapped_string).insert(offset, *self.class.u_unpack(fragment)).pack('U*')
    )
  else
    raise IndexError, "index #{offset} out of string"
  end
  self
end












#ljust(integer, padstr = ' ') ⇒ Object







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   "
















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# File 'lib/active_support/multibyte/chars.rb', line 280

def ljust(integer, padstr=' ')
  justify(integer, :left, padstr)
end












#lstrip ⇒ Object







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















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# File 'lib/active_support/multibyte/chars.rb', line 303

def lstrip
  chars(@wrapped_string.gsub(UNICODE_LEADERS_PAT, ''))
end












#normalize(form = ActiveSupport::Multibyte.default_normalization_form) ⇒ Object







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
    
















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# File 'lib/active_support/multibyte/chars.rb', line 404

def normalize(form=ActiveSupport::Multibyte.default_normalization_form)
  # See http://www.unicode.org/reports/tr15, Table 1
  codepoints = self.class.u_unpack(@wrapped_string)
  chars(case form
    when :d
      self.class.reorder_characters(self.class.decompose_codepoints(:canonical, codepoints))
    when :c
      self.class.compose_codepoints(self.class.reorder_characters(self.class.decompose_codepoints(:canonical, codepoints)))
    when :kd
      self.class.reorder_characters(self.class.decompose_codepoints(:compatability, codepoints))
    when :kc
      self.class.compose_codepoints(self.class.reorder_characters(self.class.decompose_codepoints(:compatability, codepoints)))
    else
      raise ArgumentError, "#{form} is not a valid normalization variant", caller
  end.pack('U*'))
end












#ord ⇒ Object







Returns the codepoint of the first character in the string.


Example:


'こんにちは'.mb_chars.ord #=> 12371
















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# File 'lib/active_support/multibyte/chars.rb', line 369

def ord
  self.class.u_unpack(@wrapped_string)[0]
end












#respond_to?(method, include_private = false) ⇒ Boolean







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.








Returns:


    

  • 
(Boolean)

    • 










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# File 'lib/active_support/multibyte/chars.rb', line 107

def respond_to?(method, include_private=false)
  super || @wrapped_string.respond_to?(method, include_private) || false
end












#reverse ⇒ Object







Reverses all characters in the string.


Example:


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
















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# File 'lib/active_support/multibyte/chars.rb', line 322

def reverse
  chars(self.class.g_unpack(@wrapped_string).reverse.flatten.pack('U*'))
end












#rindex(needle, offset = nil) ⇒ Object







Returns the position needle in the string, counting in codepoints, searching backward from offset or the end of the string. Returns nil if needle isn’t found.


Example:


'Café périferôl'.mb_chars.rindex('é') #=> 6
'Café périferôl'.mb_chars.rindex(/\w/u) #=> 13
















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# File 'lib/active_support/multibyte/chars.rb', line 211

def rindex(needle, offset=nil)
  offset ||= length
  wrapped_offset = self.first(offset).wrapped_string.length
  index = @wrapped_string.rindex(needle, wrapped_offset)
  index ? (self.class.u_unpack(@wrapped_string.slice(0...index)).size) : nil
end












#rjust(integer, padstr = ' ') ⇒ Object







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"
















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# File 'lib/active_support/multibyte/chars.rb', line 267

def rjust(integer, padstr=' ')
  justify(integer, :right, padstr)
end












#rstrip ⇒ Object







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















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# File 'lib/active_support/multibyte/chars.rb', line 298

def rstrip
  chars(@wrapped_string.gsub(UNICODE_TRAILERS_PAT, ''))
end












#size ⇒ Object
Also known as:
length








Returns the number of codepoints in the string















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# File 'lib/active_support/multibyte/chars.rb', line 313

def size
  self.class.u_unpack(@wrapped_string).size
end












#slice(*args) ⇒ Object
Also known as:
[]








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"
















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# File 'lib/active_support/multibyte/chars.rb', line 331

def slice(*args)
  if args.size > 2
    raise ArgumentError, "wrong number of arguments (#{args.size} for 1)" # Do as if we were native
  elsif (args.size == 2 && !(args.first.is_a?(Numeric) || args.first.is_a?(Regexp)))
    raise TypeError, "cannot convert #{args.first.class} into Integer" # Do as if we were native
  elsif (args.size == 2 && !args[1].is_a?(Numeric))
    raise TypeError, "cannot convert #{args[1].class} into Integer" # Do as if we were native
  elsif args[0].kind_of? Range
    cps = self.class.u_unpack(@wrapped_string).slice(*args)
    result = cps.nil? ? nil : cps.pack('U*')
  elsif args[0].kind_of? Regexp
    result = @wrapped_string.slice(*args)
  elsif args.size == 1 && args[0].kind_of?(Numeric)
    character = self.class.u_unpack(@wrapped_string)[args[0]]
    result = character.nil? ? nil : [character].pack('U')
  else
    result = self.class.u_unpack(@wrapped_string).slice(*args).pack('U*')
  end
  result.nil? ? nil : chars(result)
end












#slice!(*args) ⇒ Object







Like String#slice!, except instead of byte offsets you specify character offsets.


Example:


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
















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# File 'lib/active_support/multibyte/chars.rb', line 359

def slice!(*args)
  slice = self[*args]
  self[*args] = ''
  slice
end












#split(*args) ⇒ Object







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"]
















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# File 'lib/active_support/multibyte/chars.rb', line 164

def split(*args)
  @wrapped_string.split(*args).map { |i| i.mb_chars }
end












#strip ⇒ Object







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















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# File 'lib/active_support/multibyte/chars.rb', line 308

def strip
  rstrip.lstrip
end












#tidy_bytes ⇒ Object







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















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# File 'lib/active_support/multibyte/chars.rb', line 449

def tidy_bytes
  chars(self.class.tidy_bytes(@wrapped_string))
end












#upcase ⇒ Object







Convert characters in the string to uppercase.


Example:


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
















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# File 'lib/active_support/multibyte/chars.rb', line 377

def upcase
  apply_mapping :uppercase_mapping
end