* lib/rss: rss library imported. [ruby-dev:22726]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@5566 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/rss/converter.rb

@@ -0,0 +1,182 @@
+require "rss/utils"
+
+module RSS
+
+	class Converter
+		
+		include Utils
+
+		def initialize(to_enc, from_enc=nil)
+			to_enc = to_enc.downcase.gsub(/-/, '_')
+			from_enc ||= 'utf-8'
+			from_enc = from_enc.downcase.gsub(/-/, '_')
+			if to_enc == from_enc
+				def_same_enc()
+			else
+				if respond_to?("def_to_#{to_enc}_from_#{from_enc}")
+					send("def_to_#{to_enc}_from_#{from_enc}")
+				else
+					def_else_enc(to_enc, from_enc)
+				end
+			end
+		end
+
+		def convert(value)
+			value
+		end
+
+		def def_convert()
+			instance_eval(<<-EOC, *get_file_and_line_from_caller(0))
+			def convert(value)
+				if value.kind_of?(String)
+					#{yield('value')}
+				else
+					value
+				end
+			end
+			EOC
+		end
+
+		def def_iconv_convert(to_enc, from_enc)
+			begin
+				require "iconv"
+				def_convert do |value|
+					<<-EOC
+					@iconv ||= Iconv.new("#{to_enc}", "#{from_enc}")
+					begin
+						@iconv.iconv(#{value})
+					rescue Iconv::Failure
+						raise ConversionError.new(#{value}, "#{to_enc}", "#{from_enc}")
+						#{value}
+					end
+EOC
+				end
+			rescue LoadError, ArgumentError, SystemCallError
+				raise UnknownConversionMethodError.new(to_enc, from_enc)
+			end
+		end
+		
+		def def_else_enc(to_enc, from_enc)
+			raise UnknownConversionMethodError.new(to_enc, from_enc)
+		end
+		
+		def def_same_enc()
+			def_convert do |value|
+				value
+			end
+		end
+
+		def def_to_euc_jp_from_utf_8
+			begin
+				require "uconv"
+				def_convert do |value|
+					"Uconv.u8toeuc(#{value})"
+				end
+			rescue LoadError
+				def_iconv_convert('EUC-JP', 'UTF-8')
+			end
+		end
+		
+		def def_to_utf_8_from_euc_jp
+			begin
+				require "uconv"
+				def_convert do |value|
+					"Uconv.euctou8(#{value})"
+				end
+			rescue LoadError
+				def_iconv_convert('UTF-8', 'EUC-JP')
+			end
+		end
+		
+		def def_to_shift_jis_from_utf_8
+			begin
+				require "uconv"
+				def_convert do |value|
+					"Uconv.u8tosjis(#{value})"
+				end
+			rescue LoadError
+				def_iconv_convert('Shift_JIS', 'UTF-8')
+			end
+		end
+		
+		def def_to_utf_8_from_shift_jis
+			begin
+				require "uconv"
+				def_convert do |value|
+					"Uconv.sjistou8(#{value})"
+				end
+			rescue LoadError
+				def_iconv_convert('UTF-8', 'Shift_JIS')
+			end
+		end
+		
+		def def_to_euc_jp_from_shift_jis
+      begin
+        require "nkf"
+      rescue LoadError
+        raise UnknownConversionMethodError.new('EUC-JP', 'Shift_JIS')
+      end
+			def_convert do |value|
+				"NKF.nkf('-Se', #{value})"
+			end
+		end
+		
+		def def_to_shift_jis_from_euc_jp
+      begin
+        require "nkf"
+      rescue LoadError
+        raise UnknownConversionMethodError.new('Shift_JIS', 'EUC-JP')
+      end
+			def_convert do |value|
+				"NKF.nkf('-Es', #{value})"
+			end
+		end
+		
+		def def_to_euc_jp_from_iso_2022_jp
+      begin
+        require "nkf"
+      rescue LoadError
+        raise UnknownConversionMethodError.new('EUC-JP', 'ISO-2022-JP')
+      end
+			def_convert do |value|
+				"NKF.nkf('-Je', #{value})"
+			end
+		end
+		
+		def def_to_iso_2022_jp_from_euc_jp
+      begin
+        require "nkf"
+      rescue LoadError
+        raise UnknownConversionMethodError.new('ISO-2022-JP', 'EUC-JP')
+      end
+			def_convert do |value|
+				"NKF.nkf('-Ej', #{value})"
+			end
+		end
+
+		def def_to_utf_8_from_iso_8859_1
+			def_convert do |value|
+				"#{value}.unpack('C*').pack('U*')"
+			end
+		end
+		
+		def def_to_iso_8859_1_from_utf_8
+			def_convert do |value|
+				<<-EOC
+				array_utf8 = #{value}.unpack('U*')
+				array_enc = []
+				array_utf8.each do |num|
+					if num <= 0xFF
+						array_enc << num
+					else
+						array_enc.concat "&\#\#{num};".unpack('C*')
+					end
+				end
+				array_enc.pack('C*')
+EOC
+			end
+		end
+		
+	end
+	
+end