Implements multibyte methods for easier access to multibyte characters in a String instance.
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# File activesupport/lib/active_support/core_ext/string/multibyte.rb, line 57 57: def chars 58: ActiveSupport::Deprecation.warn('String#chars has been deprecated in favor of String#mb_chars.', caller) 59: mb_chars 60: 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.
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# File activesupport/lib/active_support/core_ext/string/multibyte.rb, line 52 52: def is_utf8? 53: ActiveSupport::Multibyte::Chars.consumes?(self) 54: end
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# File activesupport/lib/active_support/core_ext/string/multibyte.rb, line 67 67: def is_utf8? #:nodoc 68: case encoding 69: when Encoding::UTF_8 70: valid_encoding? 71: when Encoding::ASCII_8BIT, Encoding::US_ASCII 72: dup.force_encoding(Encoding::UTF_8).valid_encoding? 73: else 74: false 75: end 76: end
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# File activesupport/lib/active_support/core_ext/string/multibyte.rb, line 63 63: def mb_chars #:nodoc 64: self 65: end
Multibyte proxy
mb_chars is a multibyte safe proxy for string methods.
In Ruby 1.8 and older 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. If the proxy class doesn‘t respond to a certain method, it‘s forwarded to the encapsuled string.
name = 'Claus Müller' name.reverse #=> "rell??M sualC" name.length #=> 13 name.mb_chars.reverse.to_s #=> "rellüM sualC" name.mb_chars.length #=> 12
In Ruby 1.9 and newer mb_chars returns self because String is (mostly) encoding aware. This means that it becomes easy to run one version of your code on multiple Ruby versions.
Method chaining
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.mb_chars.reverse.length #=> 12
Interoperability and configuration
The Chars 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. For information about how to change the default Multibyte behaviour see ActiveSupport::Multibyte.
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# File activesupport/lib/active_support/core_ext/string/multibyte.rb, line 42 42: def mb_chars 43: if ActiveSupport::Multibyte.proxy_class.wants?(self) 44: ActiveSupport::Multibyte.proxy_class.new(self) 45: else 46: self 47: end 48: end