Add ActiveSupport::Multibyte. Provides String#chars which lets you deal with strings as a sequence of chars, not of bytes. Closes #6242 [Julian Tarkhanov, Manfred Stienstra & Jan Behrens]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@5223 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 42 insertions, 0 deletions

diff --git a/activesupport/lib/active_support/core_ext/string/unicode.rb b/activesupport/lib/active_support/core_ext/string/unicode.rb
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+++ b/activesupport/lib/active_support/core_ext/string/unicode.rb
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+module ActiveSupport #:nodoc:
+  module CoreExtensions #:nodoc:
+    module String #:nodoc:
+      # Define methods for handeling unicode data.
+      module Unicode
+        # +chars+ is a Unicode safe proxy for string methods. It creates and returns an instance of the
+        # ActiveSupport::Multibyte::Chars class which encapsulates the original string. A Unicode safe version of all
+        # the String methods are defined on this proxy class. Undefined methods are forwarded to String, so all of the
+        # string overrides can also be called through the +chars+ proxy.
+        #
+        #   name = 'Claus Müller'
+        #   name.reverse #=> "rell??M sualC"
+        #   name.length #=> 13
+        #
+        #   name.chars.reverse.to_s #=> "rellüM sualC"
+        #   name.chars.length #=> 12
+        #   
+        #
+        # All the methods on the chars proxy which normally return a string will return a Chars object. This allows
+        # method chaining on the result of any of these methods.
+        #
+        #   name.chars.reverse.length #=> 12
+        #
+        # The Char object tries to be as interchangeable with String objects as possible: sorting and comparing between
+        # String and Char work like expected. The bang! methods change the internal string representation in the Chars
+        # object. Interoperability problems can be resolved easily with a +to_s+ call.
+        #
+        # For more information about the methods defined on the Chars proxy see ActiveSupport::Multibyte::Chars and
+        # ActiveSupport::Multibyte::Handlers::UTF8Handler
+        def chars
+          ActiveSupport::Multibyte::Chars.new(self)
+        end
+
+        # Returns true if the string has UTF-8 semantics (a String used for purely byte resources is unlikely to have
+        # them), returns false otherwise.
+        def is_utf8?
+          ActiveSupport::Multibyte::Handlers::UTF8Handler.consumes?(self)
+        end
+      end
+    end
+  end
+end
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