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Contents
# = TITLE:
# Soundex
#
# = SYNOPSIS:
# Ruby implementation of the Soundex algorithm,
# as described by Knuth in volume 3 of The Art
# of Computer Programming.
#
# = AUTHOR:
# Michael Neumann (neumann@s-direktnet.de)
module English # :nodoc:
# Ruby implementation of the Soundex algorithm,
# as described by Knuth in volume 3 of The Art
# of Computer Programming.
module Soundex
module_function
# Returns nil if the value couldn't be calculated b/c of
# empty-string or invalid character.
#
# "Ruby".soundex #=> "R100"
def soundex(str)
return nil if str.empty?
str = str.upcase
last_code = soundex_code(str[0,1])
soundex_code = str[0,1]
for index in 1...(str.size) do
return soundex_code if soundex_code.size == 4
code = soundex_code(str[index,1])
if code == "0" then
last_code = nil
elsif code == nil then
return nil
elsif code != last_code then
soundex_code += code
last_code = code
end
end
return soundex_code + "000"[0,4-soundex_code.size]
end
# Support function for String#soundex.
# Returns code for a single character.
def soundex_code(char)
char.tr! "AEIOUYWHBPFVCSKGJQXZDTLMNR", "00000000111122222222334556"
end
end # module Soundex
end # module English
class String
def soundex
English::Soundex.soundex(self)
end
end
Version data entries
9 entries across 9 versions & 2 rubygems