# encoding: utf-8 module ActiveSupport #:nodoc: module Multibyte #:nodoc: # 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 class Chars # Hangul character boundaries and properties HANGUL_SBASE = 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 # All the unicode whitespace UNICODE_WHITESPACE = [ (0x0009..0x000D).to_a, # White_Space # Cc [5] .. 0x0020, # White_Space # Zs SPACE 0x0085, # White_Space # Cc 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 # 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_LEADERS_AND_TRAILERS = UNICODE_WHITESPACE + [65279] # ZERO-WIDTH NO-BREAK SPACE aka BOM # Returns a regular expression pattern that matches the passed Unicode codepoints def self.codepoints_to_pattern(array_of_codepoints) #:nodoc: array_of_codepoints.collect{ |e| [e].pack 'U*' }.join('|') end 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'] attr_reader :wrapped_string alias to_s wrapped_string alias to_str wrapped_string if '1.9'.respond_to?(:force_encoding) # Creates a new Chars instance by wrapping _string_. def initialize(string) @wrapped_string = string @wrapped_string.force_encoding(Encoding::UTF_8) unless @wrapped_string.frozen? end else def initialize(string) #:nodoc: @wrapped_string = string end end # Forward all undefined methods to the wrapped string. 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 # 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+. def respond_to?(method, include_private=false) super || @wrapped_string.respond_to?(method, include_private) || false end # Enable more predictable duck-typing on String-like classes. See Object#acts_like?. def acts_like_string? true end # Returns +true+ if the Chars class can and should act as a proxy for the string _string_. Returns # +false+ otherwise. def self.wants?(string) $KCODE == 'UTF8' && consumes?(string) end # Returns +true+ when the proxy class can handle the string. Returns +false+ otherwise. def self.consumes?(string) # Unpack is a little bit faster than regular expressions. string.unpack('U*') true rescue ArgumentError false end include Comparable # 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 def <=>(other) @wrapped_string <=> other.to_s end # Returns a new Chars object containing the _other_ object concatenated to the string. # # Example: # ('Café'.mb_chars + ' périferôl').to_s #=> "Café périferôl" def +(other) self << other end # Like String#=~ only it returns the character offset (in codepoints) instead of the byte offset. # # Example: # 'Café périferôl'.mb_chars =~ /ô/ #=> 12 def =~(other) translate_offset(@wrapped_string =~ other) 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"] def split(*args) @wrapped_string.split(*args).map { |i| i.mb_chars } end # Inserts the passed string at specified codepoint offsets. # # Example: # 'Café'.mb_chars.insert(4, ' périferôl').to_s #=> "Café périferôl" 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 # Returns +true+ if contained string contains _other_. Returns +false+ otherwise. # # Example: # 'Café'.mb_chars.include?('é') #=> true def include?(other) # We have to redefine this method because Enumerable defines it. @wrapped_string.include?(other) 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 def index(needle, offset=0) index = @wrapped_string.index(needle, offset) index ? (self.class.u_unpack(@wrapped_string.slice(0...index)).size) : nil end # 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" 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 # 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" def rjust(integer, padstr=' ') justify(integer, :right, padstr) end # 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   " def ljust(integer, padstr=' ') justify(integer, :left, padstr) 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  " def center(integer, padstr=' ') justify(integer, :center, padstr) end # Strips entire range of Unicode whitespace from the right of the string. def rstrip chars(@wrapped_string.gsub(UNICODE_TRAILERS_PAT, '')) end # Strips entire range of Unicode whitespace from the left of the string. def lstrip chars(@wrapped_string.gsub(UNICODE_LEADERS_PAT, '')) end # Strips entire range of Unicode whitespace from the right and left of the string. def strip rstrip.lstrip end # Returns the number of codepoints in the string def size self.class.u_unpack(@wrapped_string).size end alias_method :length, :size # Reverses all characters in the string. # # Example: # 'Café'.mb_chars.reverse.to_s #=> 'éfaC' def reverse chars(self.class.u_unpack(@wrapped_string).reverse.pack('U*')) 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" 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 alias_method :[], :slice # Converts first character in the string to Unicode value # # Example: # 'こんにちは'.mb_chars.ord #=> 12371 def ord self.class.u_unpack(@wrapped_string)[0] end # Convert characters in the string to uppercase. # # Example: # 'Laurent, òu sont les tests?'.mb_chars.upcase.to_s #=> "LAURENT, ÒU SONT LES TESTS?" def upcase apply_mapping :uppercase_mapping end # Convert characters in the string to lowercase. # # Example: # 'VĚDA A VÝZKUM'.mb_chars.downcase.to_s #=> "věda a výzkum" def downcase apply_mapping :lowercase_mapping end # Converts the first character to uppercase and the remainder to lowercase. # # Example: # 'über'.mb_chars.capitalize.to_s #=> "Über" def capitalize (slice(0) || chars('')).upcase + (slice(1..-1) || chars('')).downcase 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 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 # Performs canonical decomposition on all the characters. # # Example: # 'é'.length #=> 2 # 'é'.mb_chars.decompose.to_s.length #=> 3 def decompose chars(self.class.decompose_codepoints(:canonical, self.class.u_unpack(@wrapped_string)).pack('U*')) end # Performs composition on all the characters. # # Example: # 'é'.length #=> 3 # 'é'.mb_chars.compose.to_s.length #=> 2 def compose chars(self.class.compose_codepoints(self.class.u_unpack(@wrapped_string)).pack('U*')) end # Returns the number of grapheme clusters in the string. # # Example: # 'क्षि'.mb_chars.length #=> 4 # 'क्षि'.mb_chars.g_length #=> 3 def g_length self.class.g_unpack(@wrapped_string).length end # Replaces all ISO-8859-1 or CP1252 characters by their UTF-8 equivalent resulting in a valid UTF-8 string. def tidy_bytes chars(self.class.tidy_bytes(@wrapped_string)) end %w(lstrip rstrip strip reverse upcase downcase slice tidy_bytes capitalize).each do |method| define_method("#{method}!") do |*args| unless args.nil? @wrapped_string = send(method, *args).to_s else @wrapped_string = send(method).to_s end self end end class << self # 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] def u_unpack(string) begin string.unpack 'U*' rescue ArgumentError raise EncodingError, 'malformed UTF-8 character' end 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. def in_char_class?(codepoint, classes) classes.detect { |c| UCD.boundary[c] === codepoint } ? true : false 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]] 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 # Reverse operation of g_unpack. # # Example: # Chars.g_pack(Chars.g_unpack('क्षि')) #=> 'क्षि' def g_pack(unpacked) (unpacked.flatten).pack('U*') end def padding(padsize, padstr=' ') #:nodoc: if padsize != 0 new(padstr * ((padsize / u_unpack(padstr).size) + 1)).slice(0, padsize) else '' end end # Re-order codepoints so the string becomes canonical. 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 # Decompose composed characters to the decomposed form. 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 # Compose decomposed characters to the composed form. 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 # Replaces all ISO-8859-1 or CP1252 characters by their UTF-8 equivalent resulting in a valid UTF-8 string. 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 end protected def translate_offset(byte_offset) #:nodoc: return nil if byte_offset.nil? return 0 if @wrapped_string == '' chunk = @wrapped_string[0..byte_offset] begin begin chunk.unpack('U*').length - 1 rescue ArgumentError => e chunk = @wrapped_string[0..(byte_offset+=1)] # Stop retrying at the end of the string raise e unless byte_offset < chunk.length # We damaged a character, retry retry end # Catch the ArgumentError so we can throw our own rescue ArgumentError raise EncodingError, 'malformed UTF-8 character' end end def justify(integer, way, padstr=' ') #:nodoc: raise ArgumentError, "zero width padding" if padstr.length == 0 padsize = integer - size padsize = padsize > 0 ? padsize : 0 case way when :right result = @wrapped_string.dup.insert(0, self.class.padding(padsize, padstr)) when :left result = @wrapped_string.dup.insert(-1, self.class.padding(padsize, padstr)) when :center lpad = self.class.padding((padsize / 2.0).floor, padstr) rpad = self.class.padding((padsize / 2.0).ceil, padstr) result = @wrapped_string.dup.insert(0, lpad).insert(-1, rpad) end chars(result) end def apply_mapping(mapping) #:nodoc: chars(self.class.u_unpack(@wrapped_string).map do |codepoint| cp = UCD.codepoints[codepoint] if cp and (ncp = cp.send(mapping)) and ncp > 0 ncp else codepoint end end.pack('U*')) end def chars(string) #:nodoc: self.class.new(string) end end end end