JezK
Edit File: chars.rb
# encoding: utf-8 # frozen_string_literal: true require 'mail/multibyte/unicode' module Mail #: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 # Mail::Multibyte.proxy_class. # # class CharsForUTF32 # def size # @wrapped_string.size / 4 # end # # def self.accepts?(string) # string.length % 4 == 0 # end # end # # Mail::Multibyte.proxy_class = CharsForUTF32 class Chars 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.dup @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+ 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+: # # '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: # (Mail::Multibyte.mb_chars('Café') + ' 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: # Mail::Multibyte.mb_chars('Café périferôl') =~ /ô/ # => 12 def =~(other) translate_offset(@wrapped_string =~ other) end # Inserts the passed string at specified codepoint offsets. # # Example: # Mail::Multibyte.mb_chars('Café').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: # Mail::Multibyte.mb_chars('Café').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: # Mail::Multibyte.mb_chars('Café périferôl').index('ô') # => 12 # Mail::Multibyte.mb_chars('Café périferôl').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: # Mail::Multibyte.mb_chars('Café périferôl').rindex('é') # => 6 # Mail::Multibyte.mb_chars('Café périferôl').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: # Mail::Multibyte.mb_chars('こんにちは').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: # # Mail::Multibyte.mb_chars("¾ cup").rjust(8).to_s # # => " ¾ cup" # # Mail::Multibyte.mb_chars("¾ cup").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: # # Mail::Multibyte.mb_chars("¾ cup").rjust(8).to_s # # => "¾ cup " # # Mail::Multibyte.mb_chars("¾ cup").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: # # Mail::Multibyte.mb_chars("¾ cup").center(8).to_s # # => " ¾ cup " # # Mail::Multibyte.mb_chars("¾ cup").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: # Mail::Multibyte.mb_chars('Café périferôl').split(/é/).map { |part| part.upcase.to_s } # => ["CAF", " P", "RIFERÔL"] def split(*args) @wrapped_string.split(*args).map { |i| i.mb_chars } 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) if args[0].is_a?(Integer) 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?(Integer) 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 + 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 end # Reverses all characters in the string. # # Example: # Mail::Multibyte.mb_chars('Café').reverse.to_s # => 'éfaC' def reverse chars(Unicode.g_unpack(@wrapped_string).reverse.flatten.pack('U*')) end # Implements Unicode-aware slice with codepoints. Slicing on one point returns the codepoints for that # character. # # Example: # Mail::Multibyte.mb_chars('こんにちは').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: # s = 'こんにちは' # s.mb_chars.limit(7) # => "こに" def limit(limit) slice(0...translate_offset(limit)) end # Convert characters in the string to uppercase. # # Example: # Mail::Multibyte.mb_chars('Laurent, où sont les tests ?').upcase.to_s # => "LAURENT, OÙ SONT LES TESTS ?" def upcase chars(Unicode.apply_mapping(@wrapped_string, :uppercase_mapping)) end # Convert characters in the string to lowercase. # # Example: # Mail::Multibyte.mb_chars('VĚDA A VÝZKUM').downcase.to_s # => "věda a výzkum" def downcase chars(Unicode.apply_mapping(@wrapped_string, :lowercase_mapping)) end # Converts the first character to uppercase and the remainder to lowercase. # # Example: # Mail::Multibyte.mb_chars('über').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: # Mail::Multibyte.mb_chars("ÉL QUE SE ENTERÓ").titleize # => "Él Que Se Enteró" # Mail::Multibyte.mb_chars("日本語").titleize # => "日本語" def titleize chars(downcase.to_s.gsub(/\b('?\S)/u) { Unicode.apply_mapping $1, :uppercase_mapping }) 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. # # * <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 # Mail::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 # Mail::Multibyte.mb_chars('é').decompose.to_s.length # => 3 def decompose chars(Unicode.decompose_codepoints(:canonical, Unicode.u_unpack(@wrapped_string)).pack('U*')) end # Performs composition on all the characters. # # Example: # 'é'.length # => 3 # Mail::Multibyte.mb_chars('é').compose.to_s.length # => 2 def compose chars(Unicode.compose_codepoints(Unicode.u_unpack(@wrapped_string)).pack('U*')) end # Returns the number of grapheme clusters in the string. # # Example: # Mail::Multibyte.mb_chars('क्षि').length # => 4 # Mail::Multibyte.mb_chars('क्षि').g_length # => 3 def g_length Unicode.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. # # 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 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 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) end end end end