1	#------------------------------------------------------------------------------
     2	#
     3	# soundex.io -- generate soundex encodings.
     4	#
     5	# 1. Keep the first letter.
     6	#
     7	# 2. Drop all the vowels A E I O U W Y H.
     8	#
     9	# 3. Encode the remaining 3 letters into:
    10	#
    11	#      B P F V            1
    12	#      C S K G J Q X Z    2
    13	#      D T                3
    14	#      L                  4
    15	#      M N                5
    16	#      R                  6
    17	#
    18	# 4. Double letters are treated as one.
    19	#
    20	# 5. Double letters with same encoding is treated as one.
    21	#
    22	#
    23	# Tov Are Jacobsen April, 2003 <mail@tovare.com>
    24	# 
    25	# Language: http://www.iolanguage.com
    26	# Version:  2005-01-19 (Jon Kleiser)
    27	#------------------------------------------------------------------------------
       
    28	Soundex := Object clone do(
    29		encmap := Map clone do(
    30			atPut("B", 1)
    31			atPut("P", 1)
    32			atPut("F", 1)
    33			atPut("V", 1)
    34			atPut("C", 2)
    35			atPut("S", 2)
    36			atPut("K", 2)
    37			atPut("G", 2)
    38			atPut("J", 2)
    39			atPut("Q", 2)
    40			atPut("X", 2)
    41			atPut("Z", 2)
    42			atPut("D", 3)
    43			atPut("T", 3)
    44			atPut("L", 4)
    45			atPut("M", 5)
    46			atPut("N", 5)
    47			atPut("R", 6)
    48		)
    49	)
       
    50	#=========================================================================
    51	#
    52	# Converts a string into soundex encoding.
    53	# 
    54	# Arguments:
    55	#    name     String containing a surname
    56	#
    57	#=========================================================================
       
    58	Soundex encode := method(name,
    59		name = name upper
    60		ename := ""
    61		name foreach(i, s,
    62			if (i == 0) then (
    63				ename = ename append(s asCharacter)
    64			) else (
    65				# Drop all unmapped characters
    66				code := encmap at(s asCharacter)
    67				if (code != Nil,
    68					if (code asString != ename at(-1) asCharacter,
    69						ename = ename append(code)
    70						if (ename length == 4, return ename)
    71					)
    72				)
    73			)
    74		)
    75		return ename
    76	)