chars.rb in activesupport-4.0.0.beta1

- old
+ new

@@ -1,27 +1,34 @@
 # encoding: utf-8
+require 'active_support/json'
 require 'active_support/core_ext/string/access'
 require 'active_support/core_ext/string/behavior'
+require 'active_support/core_ext/module/delegation'
 
 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.
+    # 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.
+    # 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"
+    #   '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.
+    # 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
+    #   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
+    # 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
@@ -32,440 +39,180 @@
     #     end
     #   end
     #
     #   ActiveSupport::Multibyte.proxy_class = CharsForUTF32
     class Chars
+      include Comparable
       attr_reader :wrapped_string
       alias to_s wrapped_string
       alias to_str wrapped_string
 
-      if RUBY_VERSION >= "1.9"
-        # 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
+      delegate :<=>, :=~, :acts_like_string?, :to => :wrapped_string
+
+      # 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
 
       # 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
+          result = @wrapped_string.__send__(method, *args, &block)
+          self if result
         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)
+      # 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_missing?(method, include_private)
+        @wrapped_string.respond_to?(method, include_private)
       end
 
-      # Enable more predictable duck-typing on String-like classes. See Object#acts_like?.
-      def acts_like_string?
-        true
-      end
-
-      # Returns +true+ when the proxy class can handle the string. Returns +false+ otherwise.
+      # 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
+        string.encoding == Encoding::UTF_8
       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+:
+      # Works just like <tt>String#split</tt>, with the exception that the items
+      # in the resulting list are Chars instances instead of String. This makes
+      # chaining methods easier.
       #
-      #   'é'.mb_chars <=> 'ü'.mb_chars # => -1
-      #
-      # See <tt>String#<=></tt> for more details.
-      def <=>(other)
-        @wrapped_string <=> other.to_s
-      end
-
-      if RUBY_VERSION < "1.9"
-        # 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 a new Chars object containing the _other_ object concatenated to the string.
-        #
-        # Example:
-        #   ('Café'.mb_chars + ' périferôl').to_s # => "Café périferôl"
-        def +(other)
-          chars(@wrapped_string + other)
-        end
-
-        # Like <tt>String#=~</tt> 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
-
-        # Inserts the passed string at specified codepoint offsets.
-        #
-        # Example:
-        #   'Café'.mb_chars.insert(4, ' périferôl').to_s # => "Café périferôl"
-        def insert(offset, fragment)
-          unpacked = Unicode.u_unpack(@wrapped_string)
-          unless offset > unpacked.length
-            @wrapped_string.replace(
-              Unicode.u_unpack(@wrapped_string).insert(offset, *Unicode.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)
-          wrapped_offset = first(offset).wrapped_string.length
-          index = @wrapped_string.index(needle, wrapped_offset)
-          index ? (Unicode.u_unpack(@wrapped_string.slice(0...index)).size) : nil
-        end
-
-        # 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
-        def rindex(needle, offset=nil)
-          offset ||= length
-          wrapped_offset = first(offset).wrapped_string.length
-          index = @wrapped_string.rindex(needle, wrapped_offset)
-          index ? (Unicode.u_unpack(@wrapped_string.slice(0...index)).size) : nil
-        end
-
-        # Returns the number of codepoints in the string
-        def size
-          Unicode.u_unpack(@wrapped_string).size
-        end
-        alias_method :length, :size
-
-        # 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 codepoint of the first character in the string.
-        #
-        # Example:
-        #   'こんにちは'.mb_chars.ord # => 12371
-        def ord
-          Unicode.u_unpack(@wrapped_string)[0]
-        end
-
-        # Works just like <tt>String#rjust</tt>, 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 <tt>String#ljust</tt>, 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 <tt>String#center</tt>, 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
-
-      else
-        def =~(other)
-          @wrapped_string =~ other
-        end
-      end
-
-      # Works just like <tt>String#split</tt>, 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 }
+        @wrapped_string.split(*args).map { |i| self.class.new(i) }
       end
 
-      # Like <tt>String#[]=</tt>, 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 = Unicode.u_unpack(@wrapped_string)
-          case args.first
-          when 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)
-          when 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 + Unicode.u_unpack(needle).length - 1
-            range = Range.new(min, max)
-          end
-          result[range] = Unicode.u_unpack(replace_by)
-          @wrapped_string.replace(result.pack('U*'))
-        end
+      # Works like like <tt>String#slice!</tt>, but returns an instance of
+      # Chars, or nil if the string was not modified.
+      def slice!(*args)
+        chars(@wrapped_string.slice!(*args))
       end
 
       # Reverses all characters in the string.
       #
-      # Example:
       #   'Café'.mb_chars.reverse.to_s # => 'éfaC'
       def reverse
-        chars(Unicode.g_unpack(@wrapped_string).reverse.flatten.pack('U*'))
+        chars(Unicode.unpack_graphemes(@wrapped_string).reverse.flatten.pack('U*'))
       end
 
-      # Implements Unicode-aware slice with codepoints. Slicing on one point returns the codepoints for that
-      # character.
+      # Limits the byte size of the string to a number of bytes without breaking
+      # characters. Usable when the storage for a string is limited for some
+      # reason.
       #
-      # 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 = Unicode.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 = Unicode.u_unpack(@wrapped_string)[args[0]]
-          result = character && [character].pack('U')
-        else
-          cps = Unicode.u_unpack(@wrapped_string).slice(*args)
-          result = cps && cps.pack('U*')
-        end
-        result && chars(result)
-      end
-      alias_method :[], :slice
-
-      # Limit the byte size of the string to a number of bytes without breaking characters. Usable
-      # when the storage for a string is limited for some reason.
-      #
-      # Example:
       #   'こんにちは'.mb_chars.limit(7).to_s # => "こん"
       def limit(limit)
         slice(0...translate_offset(limit))
       end
 
-      # Convert characters in the string to uppercase.
+      # Converts characters in the string to uppercase.
       #
-      # Example:
       #   'Laurent, où sont les tests ?'.mb_chars.upcase.to_s # => "LAURENT, OÙ SONT LES TESTS ?"
       def upcase
-        chars(Unicode.apply_mapping @wrapped_string, :uppercase_mapping)
+        chars Unicode.upcase(@wrapped_string)
       end
 
-      # Convert characters in the string to lowercase.
+      # Converts characters in the string to lowercase.
       #
-      # Example:
       #   'VĚDA A VÝZKUM'.mb_chars.downcase.to_s # => "věda a výzkum"
       def downcase
-        chars(Unicode.apply_mapping @wrapped_string, :lowercase_mapping)
+        chars Unicode.downcase(@wrapped_string)
       end
 
+      # Converts characters in the string to the opposite case.
+      #
+      #    'El Cañón".mb_chars.swapcase.to_s # => "eL cAÑÓN"
+      def swapcase
+        chars Unicode.swapcase(@wrapped_string)
+      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
 
       # Capitalizes the first letter of every word, when possible.
       #
-      # Example:
       #   "ÉL QUE SE ENTERÓ".mb_chars.titleize    # => "Él Que Se Enteró"
       #   "日本語".mb_chars.titleize                 # => "日本語"
       def titleize
-        chars(downcase.to_s.gsub(/\b('?[\S])/u) { Unicode.apply_mapping $1, :uppercase_mapping })
+        chars(downcase.to_s.gsub(/\b('?\S)/u) { Unicode.upcase($1)})
       end
       alias_method :titlecase, :titleize
 
-      # Returns the KC normalization of the string by default. NFKC is considered the best normalization form for
-      # passing strings to databases and validations.
+      # Returns the KC normalization of the string by default. NFKC is
+      # considered the best normalization form for passing strings to databases
+      # and validations.
       #
       # * <tt>form</tt> - The form you want to normalize in. Should be one of the following:
       #   <tt>:c</tt>, <tt>:kc</tt>, <tt>:d</tt>, or <tt>:kd</tt>. Default is
       #   ActiveSupport::Multibyte::Unicode.default_normalization_form
       def normalize(form = nil)
         chars(Unicode.normalize(@wrapped_string, form))
       end
 
       # Performs canonical decomposition on all the characters.
       #
-      # Example:
       #   'é'.length                         # => 2
       #   'é'.mb_chars.decompose.to_s.length # => 3
       def decompose
-        chars(Unicode.decompose_codepoints(:canonical, Unicode.u_unpack(@wrapped_string)).pack('U*'))
+        chars(Unicode.decompose(:canonical, @wrapped_string.codepoints.to_a).pack('U*'))
       end
 
       # Performs composition on all the characters.
       #
-      # Example:
       #   'é'.length                       # => 3
       #   'é'.mb_chars.compose.to_s.length # => 2
       def compose
-        chars(Unicode.compose_codepoints(Unicode.u_unpack(@wrapped_string)).pack('U*'))
+        chars(Unicode.compose(@wrapped_string.codepoints.to_a).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
-        Unicode.g_unpack(@wrapped_string).length
+      #   'क्षि'.mb_chars.grapheme_length # => 3
+      def grapheme_length
+        Unicode.unpack_graphemes(@wrapped_string).length
       end
 
-      # Replaces all ISO-8859-1 or CP1252 characters by their UTF-8 equivalent resulting in a valid UTF-8 string.
+      # Replaces all ISO-8859-1 or CP1252 characters by their UTF-8 equivalent
+      # resulting in a valid UTF-8 string.
       #
-      # Passing +true+ will forcibly tidy all bytes, assuming that the string's encoding is entirely CP1252 or ISO-8859-1.
+      # Passing +true+ will forcibly tidy all bytes, assuming that the string's
+      # encoding is entirely CP1252 or ISO-8859-1.
       def tidy_bytes(force = false)
         chars(Unicode.tidy_bytes(@wrapped_string, force))
       end
 
-       %w(capitalize downcase lstrip reverse rstrip slice strip tidy_bytes upcase).each do |method|
-        # Only define a corresponding bang method for methods defined in the proxy; On 1.9 the proxy will
-        # exclude lstrip!, rstrip! and strip! because they are already work as expected on multibyte strings.
-        if public_method_defined?(method)
-          define_method("#{method}!") do |*args|
-            @wrapped_string = send(args.nil? ? method : method, *args).to_s
-            self
-          end
+      def as_json(options = nil) #:nodoc:
+        to_s.as_json(options)
+      end
+
+      %w(capitalize downcase reverse tidy_bytes upcase).each do |method|
+        define_method("#{method}!") do |*args|
+          @wrapped_string = send(method, *args).to_s
+          self
         end
       end
 
       protected
 
         def translate_offset(byte_offset) #:nodoc:
           return nil if byte_offset.nil?
           return 0   if @wrapped_string == ''
 
-          if @wrapped_string.respond_to?(:force_encoding)
-            @wrapped_string = @wrapped_string.dup.force_encoding(Encoding::ASCII_8BIT)
-          end
-
           begin
-            @wrapped_string[0...byte_offset].unpack('U*').length
+            @wrapped_string.byteslice(0...byte_offset).unpack('U*').length
           rescue ArgumentError
             byte_offset -= 1
             retry
-          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, padding(padsize, padstr))
-          when :left
-            result = @wrapped_string.dup.insert(-1, padding(padsize, padstr))
-          when :center
-            lpad = padding((padsize / 2.0).floor, padstr)
-            rpad = padding((padsize / 2.0).ceil, padstr)
-            result = @wrapped_string.dup.insert(0, lpad).insert(-1, rpad)
-          end
-          chars(result)
-        end
-
-        def padding(padsize, padstr=' ') #:nodoc:
-          if padsize != 0
-            chars(padstr * ((padsize / Unicode.u_unpack(padstr).size) + 1)).slice(0, padsize)
-          else
-            ''
           end
         end
 
         def chars(string) #:nodoc:
           self.class.new(string)