Soundex

From Rosetta Code
Task
Soundex
You are encouraged to solve this task according to the task description, using any language you may know.

Soundex is an algorithm for creating indices for words based on their pronunciation.


Task

The goal is for homophones to be encoded to the same representation so that they can be matched despite minor differences in spelling (from the WP article).

Caution

There is a major issue in many of the implementations concerning the separation of two consonants that have the same soundex code! According to the official Rules [[1]]. So check for instance if Ashcraft is coded to A-261.

  • If a vowel (A, E, I, O, U) separates two consonants that have the same soundex code, the consonant to the right of the vowel is coded. Tymczak is coded as T-522 (T, 5 for the M, 2 for the C, Z ignored (see "Side-by-Side" rule above), 2 for the K). Since the vowel "A" separates the Z and K, the K is coded.
  • If "H" or "W" separate two consonants that have the same soundex code, the consonant to the right of the vowel is not coded. Example: Ashcraft is coded A-261 (A, 2 for the S, C ignored, 6 for the R, 1 for the F). It is not coded A-226.

360 Assembly

Translation of: VBScript

An example of the use of the TR opcode (translate) and the uppercase trick by 'or' with space (X'40'). <lang 360asm>* Soundex 02/04/2017 SOUNDEX CSECT

        USING  SOUNDEX,R13        base register
        B      72(R15)            skip savearea
        DC     17F'0'             savearea
        STM    R14,R12,12(R13)    save previous context
        ST     R13,4(R15)         link backward
        ST     R15,8(R13)         link forward
        LR     R13,R15            set addressability
        LA     R6,1               i=1
      DO WHILE=(C,R6,LE,=A(NTT))  do i=1 to hbound(tt)
        LR     R1,R6                i
        BCTR   R1,0                 -1
        MH     R1,=AL2(L'TT)        *length(tt)
        LA     R4,TT(R1)            @tt(i)
        MVC    S,0(R4)              s=tt(i)
        LA     R1,S                 @s
        LA     R2,L'S               length(s)

LOOP OI 0(R1),C' ' loop s[l]=ucase(s[l])

        LA     R1,1(R1)               @s++
        BCT    R2,LOOP              endloop
        MVC    CODE,=C'0000'        code='0000'
        MVC    CODE(1),S            code[1]=s[1]
        LA     R8,1                 k=1
        LA     R7,1                 j=1
      DO WHILE=(C,R7,LE,=A(L'S))    do j=1 to length(s)
        LA     R4,S-1                 @s[0]
        AR     R4,R7                  +j
        MVC    CCUR,0(R4)             ccur=s[j]
        TR     CCUR,TABLE             ccur=translate(ccur,table)
      IF C,R7,EQ,=F'1' THEN           if j=1 then
        MVC    CPREV,CCUR               cprev=ccur
      ELSE     ,                      else
  • if ccur<>' ' and ccur<>'-'
      IF CLI,CCUR,NE,C' ',AND,CLI,CCUR,NE,C'-',                       *
              AND,CLC,CCUR,NE,CPREV THEN  and ccur<>cprev then
      IF C,R8,LT,=F'4' THEN               if k<4 then
        LA     R8,1(R8)                     k=k+1
        LA     R4,CODE-1(R8)                @code[k]
        MVC    0(1,R4),CCUR                 code[k]=ccur
      ENDIF    ,                          endif
      ENDIF    ,                        endif
      IF CLI,CCUR,NE,C'-' THEN          if ccur<>'-' then
        MVC    CPREV,CCUR                 cprev=ccur
      ENDIF    ,                        endif
      ENDIF    ,                      endif
        LA     R7,1(R7)               j++
      ENDDO    ,                    enddo j
        XDECO  R6,XDEC              edit i
        MVC    PG(2),XDEC+10        i
        MVC    PG+3(L'S),S          s
        MVC    PG+15(L'CODE),CODE   code
        XPRNT  PG,L'PG              print
        LA     R6,1(R6)             i++
      ENDDO    ,                  enddo i
        L      R13,4(0,R13)       restore previous savearea pointer
        LM     R14,R12,12(R13)    restore previous context
        XR     R15,R15            rc=0
        BR     R14                exit

TT DC CL12'ashcraft',CL12'ashcroft',CL12'gauss',CL12'ghosh'

        DC     CL12'hilbert',CL12'heilbronn',CL12'lee',CL12'lloyd'
        DC     CL12'moses',CL12'pfister',CL12'robert',CL12'rupert'
        DC     CL12'rubin',CL12'tymczak',CL12'soundex',CL12'example'

TTEND EQU * NTT EQU (TTEND-TT)/L'TT hbound(tt) S DS CL12 CCUR DS CL1 current CPREV DS CL1 previous CODE DS CL4 PG DC CL80' ' XDEC DS CL12 TABLE DC CL256' ' translation table

        ORG    TABLE+C'A'
        DC     CL9' 123 12- '     ABCDEFGHI
        ORG    TABLE+C'J'
        DC     CL9'22455 126'     JKLMNOPQR
        ORG    TABLE+C'S'
        DC     CL9'23 1-2 2'      STUVWXYZ
        ORG
        YREGS
        END    SOUNDEX</lang>
Output:
 1 ASHCRAFT    A261
 2 ASHCROFT    A261
 3 GAUSS       G200
 4 GHOSH       G200
 5 HILBERT     H416
 6 HEILBRONN   H416
 7 LEE         L000
 8 LLOYD       L300
 9 MOSES       M220
10 PFISTER     P236
11 ROBERT      R163
12 RUPERT      R163
13 RUBIN       R150
14 TYMCZAK     T522
15 SOUNDEX     S532
16 EXAMPLE     E251


Ada

<lang Ada>with Ada.Text_IO; use Ada.Text_IO; with Ada.Strings.Unbounded; use Ada.Strings.Unbounded; with Ada.Characters.Handling; use Ada.Characters.Handling; procedure Soundex is

  type UStrings is array(Natural range <>) of Unbounded_String;
  function "+"(S:String) return Unbounded_String renames To_Unbounded_String;
  
  function toSoundex (instr : String) return String is
     str  : String := To_Upper(instr);
     output : String := "0000";
     spos : Integer := str'First+1;  opos : Positive := 2;
     map  : array(0..255) of Character := (others => ' ');
     last : Integer := str'First;
  begin
     map(65..90) := " 123 12- 22455 12623 1-2 2";
     for i in str'Range loop str(i) := map(Character'Pos(str(i))); end loop;
     output(1) := str(str'First);
     while (opos <= 4 and spos <= str'Last) loop
        if str(spos) /= '-' and str(spos) /= ' ' then
           if (str(spos-1) = '-' and last = spos-2) and then
             (str(spos) = str(spos-2)) then null;
           elsif (str(spos) = output(opos-1) and last = spos-1) then last := spos;
           else output(opos) := str(spos);  opos := opos + 1; last := spos;
           end if;
        end if;
        spos := spos + 1;
     end loop;
     output(1) := To_Upper(instr(instr'First));
     return output;
  end toSoundex;
  
  cases : constant UStrings := (+"Soundex", +"Example", +"Sownteks",
     +"Ekzampul", +"Euler", +"Gauss", +"Hilbert", +"Knuth", +"Lloyd",
     +"Lukasiewicz", +"Ellery", +"Ghosh", +"Heilbronn", +"Kant",
     +"Ladd", +"Lissajous", +"Wheaton", +"Burroughs", +"Burrows",
     +"O'Hara", +"Washington", +"Lee", +"Gutierrez", +"Pfister",
     +"Jackson", +"Tymczak", +"VanDeusen", +"Ashcraft");

begin

  for i in cases'Range loop
     Put_Line(To_String(cases(i))&" = "&toSoundex(To_String(cases(i))));
  end loop;

end Soundex;</lang>

Output:
Soundex = S532
Example = E251
Sownteks = S532
Ekzampul = E251
Euler = E460
Gauss = G200
Hilbert = H416
Knuth = K530
Lloyd = L300
Lukasiewicz = L222
Ellery = E460
Ghosh = G200
Heilbronn = H416
Kant = K530
Ladd = L300
Lissajous = L222
Wheaton = W350
Burroughs = B620
Burrows = B620
O'Hara = O600
Washington = W252
Lee = L000
Gutierrez = G362
Pfister = P236
Jackson = J250
Tymczak = T522
VanDeusen = V532
Ashcraft = A261

ALGOL 68

Translation of: C
Works with: ALGOL 68G version Any - tested with release 2.2.0

Note: The only non-standard prelude functions used are to lower, is alpha, and is digit. These are easy enough to write, vide String case <lang Algol68> PROC soundex = (STRING s) STRING:

   BEGIN
       PROC encode = (CHAR c) CHAR:
       BEGIN
           # We assume the alphabet is contiguous. #
           "-123-12*-22455-12623-1*2-2"[ABS to lower(c) - ABS "a" + 1]
       END;
       INT soundex code length = 4;
       STRING result := soundex code length * "0";
       IF s /= "" THEN
           CHAR previous;
           INT  j;
           result[j := 1] := s[1];
           previous := encode(s[1]);
           FOR i FROM 2 TO UPB s WHILE j < soundex code length
           DO
               IF is alpha(s[i]) THEN
                   CHAR code = encode(s[i]);
                   IF is digit(code) AND code /= previous THEN
                       result[j +:= 1] := code;
                       previous := code
                   ELIF code = "-" THEN
                       # Only vowels (y counts here) hide the last-added character #
                       previous := code
                   FI
               FI
           OD
       FI;
       result
   END;
   
   # Test code to persuade one that it does work. #
   
   MODE TEST = STRUCT (STRING input, STRING expected output);
   
   [] TEST soundex test = (
       ("Soundex",    "S532"), ("Example",     "E251"),
       ("Sownteks",   "S532"), ("Ekzampul",    "E251"),
       ("Euler",      "E460"), ("Gauss",       "G200"),
       ("Hilbert",    "H416"), ("Knuth",       "K530"),
       ("Lloyd",      "L300"), ("Lukasiewicz", "L222"),
       ("Ellery",     "E460"), ("Ghosh",       "G200"),
       ("Heilbronn",  "H416"), ("Kant",        "K530"),
       ("Ladd",       "L300"), ("Lissajous",   "L222"),
       ("Wheaton",    "W350"), ("Burroughs",   "B620"),
       ("Burrows",    "B620"), ("O'Hara",      "O600"),
       ("Washington", "W252"), ("Lee",         "L000"),
       ("Gutierrez",  "G362"), ("Pfister",     "P236"),
       ("Jackson",    "J250"), ("Tymczak",     "T522"),
       ("VanDeusen",  "V532"), ("Ashcraft",    "A261")
   );
   
   #
     Apologies for the magic number in the padding of the input
     and the wired-in heading.
   #
   
   print(("Test name   Code Got", newline, "----------------------", newline));
   FOR i FROM LWB soundex test TO UPB soundex test
   DO
       STRING output = soundex(input OF soundex test[i]);
       printf(($g, n (12 - UPB input OF soundex test[i]) x$, input OF soundex test[i]));
       printf(($g, 1x, g, 1x$, expected output OF soundex test[i], output));
       printf(($b("ok", "not ok"), 1l$, output = expected output OF soundex test[i]))
   OD</lang>

ANSI Standard BASIC

Translation of: BBC Basic

Note: Line numbers (strict ANSI interpretation), LET and the variable after NEXT are not optional.

<lang ANSI>DECLARE EXTERNAL FUNCTION FNSoundex$

100 DATA Ashcraft, Ashcroft, Gauss, Ghosh, Hilbert, Heilbronn, Lee, Lloyd 110 DATA Moses, Pfister, Robert, Rupert, Rubin, Tymczak, Soundex, Example 120 FOR i = 1 TO 16 130 READ name$ 140 PRINT """"; name$; """"; TAB(15); FNsoundex$(name$) 150 NEXT i 160 END 170 180 EXTERNAL FUNCTION FNsoundex$(name$) 190 LET name$ = UCASE$(name$) 200 LET n$ = "01230129022455012623019202" 210 LET s$ = name$(1:1) 220 LET p = VAL(n$(ORD(s$) - 64 : ORD(s$) - 64)) 230 FOR i = 2 TO LEN(name$) 240 LET n = VAL(n$(ORD(name$(i:i)) - 64: ORD(name$(i:i)) - 64)) 250 IF n <> 0 AND n <> 9 AND n <> p THEN LET s$ = s$ & STR$(n) 260 IF n <> 9 THEN LET p = n 270 NEXT i 280 LET s$ = s$ & "000" 290 LET FNSoundex$ = s$(1:4) 300 END FUNCTION</lang>

AutoHotkey

Translation of: VBScript

<lang AutoHotkey>getCode(c){

       If c in B,F,P,V
           return 1
       If c in C,G,J,K,Q,S,X,Z
           return 2
       If c in D,T
           return 3
       If c = L
           return 4
       If c in M,N
           return 5
       If c = R
           return 6

}

soundex(s){

   code := SubStr(s, 1, 1)
  ,previous := 7
  ,i := 1
   While ++i <= StrLen(s){
       current := getCode(SubStr(s, i, 1))
       If StrLen(current) > 0 And current <> previous
           code := code . current
       previous := current
   }
   soundex := SubStr(code, 1, 4)
   If StrLen(code) < 4
       soundex .= String(4 - StrLen(code), "0")
   return soundex

}

String(a, n){

  Loop n
     o .= a
  return a

}

MsgBox % Soundex("Soundex") "`n" Soundex("Sowndeks") "`n" Soundex("Ashcroft") "`n" Soundex("Ashkrofd")</lang>

AWK

The soundex function is embedded in a program to build a table of soundex "homonyms".

<lang awk>#!/usr/bin/awk -f BEGIN {

   subsep = ", "
   delete homs

}

/^[a-zA-Z]/ {

   sdx = strToSoundex($0)
   addHom(sdx, $0)

}

END {

   showHoms(3)

}

function strToSoundex(s, sdx, i, ch, cd, lch) {

   if (length(s) == 0) return ""
   s = tolower(s)
   lch = substr(s, 1, 1);
   sdx = toupper(lch)
   lch = charToSoundex(lch)
   for (i = 2; i <= length(s); i++) {
       ch = substr(s, i, 1)
       cd = charToSoundex(ch)
       if (cd == 7) continue;
       if (cd && cd != lch) sdx = sdx cd
       lch = cd
   }
   sdx = substr(sdx "0000", 1, 4)
   return sdx

}

function charToSoundex(ch, cd) {

   if      (ch ~ /[bfpv]/)     cd = 1
   else if (ch ~ /[cgjkqsxz]/) cd = 2
   else if (ch ~ /[dt]/)       cd = 3
   else if (ch == "l")         cd = 4
   else if (ch ~ /[mn]/)       cd = 5
   else if (ch == "r")         cd = 6
   else if (ch ~ /[hw]/)       cd = 7
   else                        cd = 0
   return cd;

}

function addHom(sdx, word) {

   if (!(homs[sdx])) homs[sdx] = ""
   homs[sdx] = homs[sdx] (homs[sdx] == "" ? "" : subsep) word

}

function showHoms(toShow, i, n, wl, j) {

   for (i in homs) {
       printf i " "
       n = split(homs[i], wl, subsep)
       for (j = 1; j <= toShow && j <= n; j++) {
           printf wl[j] "  " 
       }
       print (n > toShow ? "..." : "")
   }

} </lang>


Example run:

# ./soundex.awk ../unixdict.txt |sort
A000 a  aaa  aau  ...
A100 a&p  aba  abbe  ...
A110 ababa  above  aviv  
A111 aboveboard  
A112 aboveground  
A114 affable  
A115 abovementioned  
A120 aback  abase  abash  ...
A121 abusable  abusive  appeasable  
A122 abacus  abject  abscess  ...
A123 abstain  abstention  abstinent  ...
A124 abigail  absolute  absolution  ...
A125 absence  absent  absentee  ...
A126 absorb  absorbent  absorption  ...
A130 abate  abbot  abbott  ...
A131 affidavit  
A132 abdicate  abduct  abidjan  ...
A133 abetted  abutted  apathetic  ...
A135 abdomen  abdominal  abetting  ...
A136 abater  aftereffect  afterglow  ...
A140 abel  able  afoul  ...
A141 appleby  
A142 abelson  ablaze  abolish  ...
.
.
.
Z324 zodiacal  
Z400 zeal  
Z420 zealous  zilch  zoology  
Z430 zealot  zloty  
Z453 zealand  
Z461 zellerbach  
Z500 zan  zen  zion  ...
Z510 zambia  zomba  zombie  
Z520 zinc  zing  
Z521 zanzibar  
Z525 zionism  
Z530 zenith  
Z532 zounds  
Z565 zimmerman  
Z600 zaire  zero  
Z620 zeroes  zurich  
Z623 zoroaster  zoroastrian  
Z625 zircon  zirconium  
Z630 zeroth  
Z650 zorn  
#

BBC BASIC

<lang bbcbasic> DATA Ashcraft, Ashcroft, Gauss, Ghosh, Hilbert, Heilbronn, Lee, Lloyd

     DATA Moses, Pfister, Robert, Rupert, Rubin, Tymczak, Soundex, Example
     FOR i% = 1 TO 16
       READ name$
       PRINT """" name$ """" TAB(15) FNsoundex(name$)
     NEXT
     END
     
     DEF FNsoundex(name$)
     LOCAL i%, n%, p%, n$, s$
     name$ = FNupper(name$)
     n$ = "01230129022455012623019202"
     s$ = LEFT$(name$,1)
     p% = VALMID$(n$, ASCs$ - 64, 1)
     FOR i% = 2 TO LEN(name$)
       n% = VALMID$(n$, ASCMID$(name$,i%,1) - 64, 1)
       IF n% IF n% <> 9 IF n% <> p% s$ += STR$(n%)
       IF n% <> 9 p% = n%
     NEXT
     = LEFT$(s$ + "000", 4)
     
     DEF FNupper(A$)
     LOCAL A%,C%
     FOR A% = 1 TO LEN(A$)
       C% = ASCMID$(A$,A%)
       IF C% >= 97 IF C% <= 122 MID$(A$,A%,1) = CHR$(C%-32)
     NEXT
     = A$</lang>
Output:
"Ashcraft"     A261
"Ashcroft"     A261
"Gauss"        G200
"Ghosh"        G200
"Hilbert"      H416
"Heilbronn"    H416
"Lee"          L000
"Lloyd"        L300
"Moses"        M220
"Pfister"      P236
"Robert"       R163
"Rupert"       R163
"Rubin"        R150
"Tymczak"      T522
"Soundex"      S532
"Example"      E251

Befunge

This is an implementation of the earlier Knuth soundex algorithm - compatible with PHP - which doesn't support the "HW" rule.

The word to translate is read from stdin, and its corresponding soundex encoding is written to stdout.

<lang befunge>>:~>:48*\`#v_::"`"`\"{"\`*v ^$$_v#!*`*8 8\`\"["::-**84< >$1^>:88*>v>$$1->vp7+2\"0"< |!-g71:g8-< >1+::3`!>| >17p\:!v@p7 10,+55$$<$ v+1p7+2_\$17g\17gv>>+:>5`|2 v$$:$$_^#\<1!-"0"<^1,<g7:<< v?????????????????????????? v01230120022455012623010202</lang>

Output:
(multiple runs)
Euler
E460
Gauss
G200
Hilbert
H416
Knuth
K530
Lloyd
L300
Lukasiewicz
L222
O'Hara
O600
Ashcraft
A226

C

Some string examples and rules from [[2]]. <lang c>#include <stdio.h>

  1. include <stdlib.h>
  2. include <string.h>
  3. include <ctype.h>

/* for ASCII only */ static char code[128] = { 0 }; void add_code(const char *s, int c) { while (*s) { code[(int)*s] = code[0x20 ^ (int)*s] = c; s++; } }

void init() { static const char *cls[] = { "AEIOU", "", "BFPV", "CGJKQSXZ", "DT", "L", "MN", "R", 0}; int i; for (i = 0; cls[i]; i++) add_code(cls[i], i - 1); }

/* returns a static buffer; user must copy if want to save

  result across calls */

const char* soundex(const char *s) { static char out[5]; int c, prev, i;

out[0] = out[4] = 0; if (!s || !*s) return out;

out[0] = *s++;

/* first letter, though not coded, can still affect next letter: Pfister */ prev = code[(int)out[0]]; for (i = 1; *s && i < 4; s++) { if ((c = code[(int)*s]) == prev) continue;

if (c == -1) prev = 0; /* vowel as separator */ else if (c > 0) { out[i++] = c + '0'; prev = c; } } while (i < 4) out[i++] = '0'; return out; }

int main() { int i; const char *sdx, *names[][2] = { {"Soundex", "S532"}, {"Example", "E251"}, {"Sownteks", "S532"}, {"Ekzampul", "E251"}, {"Euler", "E460"}, {"Gauss", "G200"}, {"Hilbert", "H416"}, {"Knuth", "K530"}, {"Lloyd", "L300"}, {"Lukasiewicz", "L222"}, {"Ellery", "E460"}, {"Ghosh", "G200"}, {"Heilbronn", "H416"}, {"Kant", "K530"}, {"Ladd", "L300"}, {"Lissajous", "L222"}, {"Wheaton", "W350"}, {"Burroughs", "B620"}, {"Burrows", "B620"}, {"O'Hara", "O600"}, {"Washington", "W252"}, {"Lee", "L000"}, {"Gutierrez", "G362"}, {"Pfister", "P236"}, {"Jackson", "J250"}, {"Tymczak", "T522"}, {"VanDeusen", "V532"}, {"Ashcraft", "A261"}, {0, 0} };

init();

puts(" Test name Code Got\n----------------------"); for (i = 0; names[i][0]; i++) { sdx = soundex(names[i][0]); printf("%11s %s %s ", names[i][0], names[i][1], sdx); printf("%s\n", strcmp(sdx, names[i][1]) ? "not ok" : "ok"); }

return 0; }</lang>

C#

<lang c sharp>using System; using System.Collections.Generic; using System.Linq;

namespace Soundex {

   internal static class Program
   {
       private static void Main()
       {
           var testWords = new TestWords
                               {
                                   {"Soundex", "S532"},
                                   {"Example", "E251"},
                                   {"Sownteks", "S532"},
                                   {"Ekzampul", "E251"},
                                   {"Euler", "E460"},
                                   {"Gauss", "G200"},
                                   {"Hilbert", "H416"},
                                   {"Knuth", "K530"},
                                   {"Lloyd", "L300"},
                                   {"Lukasiewicz", "L222"},
                                   {"Ellery", "E460"},
                                   {"Ghosh", "G200"},
                                   {"Heilbronn", "H416"},
                                   {"Kant", "K530"},
                                   {"Ladd", "L300"},
                                   {"Lissajous", "L222"},
                                   {"Wheaton", "W350"},
                                   {"Burroughs", "B620"},
                                   {"Burrows", "B620"},
                                   {"O'Hara", "O600"},
                                   {"Washington", "W252"},
                                   {"Lee", "L000"},
                                   {"Gutierrez", "G362"},
                                   {"Pfister", "P236"},
                                   {"Jackson", "J250"},
                                   {"Tymczak", "T522"},
                                   {"VanDeusen", "V532"},
                                   {"Ashcraft", "A261"}
                               };
           foreach (var testWord in testWords)
               Console.WriteLine("{0} -> {1} ({2})", testWord.Word.PadRight(11), testWord.ActualSoundex,
                                 (testWord.ExpectedSoundex == testWord.ActualSoundex));
       }
       // List<TestWord> wrapper to make declaration simpler.
       private class TestWords : List<TestWord> 
       {
           public void Add(string word, string expectedSoundex)
           {
               Add(new TestWord(word, expectedSoundex));
           }
       }
       private class TestWord
       {
           public TestWord(string word, string expectedSoundex)
           {
               Word = word;
               ExpectedSoundex = expectedSoundex;
               ActualSoundex = Soundex(word);
           }
           public string Word { get; private set; }
           public string ExpectedSoundex { get; private set; }
           public string ActualSoundex { get; private set; }
       }
       private static string Soundex(string word)
       {
           const string soundexAlphabet = "0123012#02245501262301#202";
           string soundexString = "";
           char lastSoundexChar = '?';
           word = word.ToUpper();
           foreach (var c in from ch in word
                             where ch >= 'A' &&
                                   ch <= 'Z' &&
                                   soundexString.Length < 4
                             select ch)
           {
               char thisSoundexChar = soundexAlphabet[c - 'A'];
               if (soundexString.Length == 0)
                   soundexString += c;
               else if (thisSoundexChar == '#')
                   continue;
               else if (thisSoundexChar != '0' &&
                        thisSoundexChar != lastSoundexChar)
                   soundexString += thisSoundexChar;
               lastSoundexChar = thisSoundexChar;
           }
           return soundexString.PadRight(4, '0');
       }
   }

}</lang>

Output:
Soundex     -> S532 (True)
Example     -> E251 (True)
Sownteks    -> S532 (True)
Ekzampul    -> E251 (True)
Euler       -> E460 (True)
Gauss       -> G200 (True)
Hilbert     -> H416 (True)
Knuth       -> K530 (True)
Lloyd       -> L300 (True)
Lukasiewicz -> L222 (True)
Ellery      -> E460 (True)
Ghosh       -> G200 (True)
Heilbronn   -> H416 (True)
Kant        -> K530 (True)
Ladd        -> L300 (True)
Lissajous   -> L222 (True)
Wheaton     -> W350 (True)
Burroughs   -> B620 (True)
Burrows     -> B620 (True)
O'Hara      -> O600 (True)
Washington  -> W252 (True)
Lee         -> L000 (True)
Gutierrez   -> G362 (True)
Pfister     -> P236 (True)
Jackson     -> J250 (True)
Tymczak     -> T522 (True)
VanDeusen   -> V532 (True)
Ashcraft    -> A261 (True)

Caché ObjectScript

<lang cos> Class Utils.Phonetic [ Abstract ] {

ClassMethod ToSoundex(String As %String) As %String [ Language = mvbasic ] { Return Soundex(String) }

} </lang>

Examples:
USER>For  { Read !, name Quit:name=""  Write " = ", ##class(Utils.Phonetic).ToSoundex(name) }

Soundex = S532
Example = E251
Sownteks = S532
Ekzampul = E251
Euler = E460
Gauss = G200
Hilbert = H416
Knuth = K530
Lloyd = L300
Lukasiewicz = L222
Ellery = E460
Ghosh = G200
Heilbronn = H416
Kant = K530
Ladd = L300
Lissajous = L222
Wheaton = W350
Burroughs = B620
Burrows = B620
O'Hara = O600
Washington = W252
Lee = L000
Gutierrez = G362
Pfister = P236
Jackson = J250
Tymczak = T522
VanDeusen = V532
Ashcraft = A261

Clipper/XBase++

<lang Clipper/XBase++>FUNCTION Soundex(cWord)

/*

This is a Clipper/XBase++ implementation of the standard American Soundex procedure. 
*/

LOCAL cSoundex, i, nLast, cChar, nCode

cWord:=ALLTRIM(UPPER(cWord)) cSoundex:=LEFT(cWord, 1) // first letter is first char nLast:=-1 FOR i:=2 TO LEN(cWord)

  cChar:=SUBSTR(cWord, i, 1)   // get char
  nCode:=SoundexCode(cChar)    // get soundex code for char
  IF nCode=0                   // if 0, ignore
     LOOP
  ENDIF
  IF nCode#nLast               // if not same code, add to soundex
     nLast:=nCode              // and replace the last one
     cSoundex+=STR(nCode, 1)
  ENDIF

NEXT cSoundex:=PADR(cSoundex, 4, "0")

RETURN(cSoundex)

STATIC FUNCTION SoundexCode(cLetter) LOCAL aCodes:={"BFPV", "CGJKQSXZ", "DT", "L", "MN", "R"}, i, nRet:=0

FOR i:=1 TO LEN(aCodes)

  IF cLetter $ aCodes[i]
     nRet:=i
     EXIT
  ENDIF

NEXT

RETURN(nRet)

FUNCTION SoundexDifference(cSound1, cSound2) LOCAL nMatch:=0, nLen1, nLen2, i

nLen1:=LEN(cSound1) nLen2:=LEN(cSound2)

// make the two words the same length. This is a safety. They both should be 4 characters long. IF nLen1 > nLen2

  cSound2:=PADR(cSound2, nLen1-nLen2, "0")

ELSEIF nLen1 < nLen2

  cSound1:=PADR(cSound1, nLen2-nLen1, "0")

ENDIF

// compare the corresponding characters between the two words FOR i:=1 TO LEN(cSound1)

  IF SUBSTR(cSound1, i, 1) == SUBSTR(cSound2, i, 1)
     ++nMatch
  ENDIF

NEXT

RETURN(nMatch)

                                                                                                                                                              • </lang>

--Clippersolutions 23:14, 4 November 2010 (UTC)--Clippersolutions 23:14, 4 November 2010 (UTC)

Clojure

<lang Clojure>(defn get-code [c]

 (case c
   (\B \F \P \V) 1
   (\C \G \J \K
    \Q \S \X \Z) 2
   (\D \T) 3
   \L 4
   (\M \N) 5
   \R 6
   nil)) ;(\A \E \I \O \U \H \W \Y)

(defn soundex [s]

 (let [[f & s] (.toUpperCase s)]
   (-> (map get-code s)

distinct (concat , "0000") (->> (cons f ,) (remove nil? ,) (take 4 ,) (apply str ,)))))</lang>

Bug here? The distinct function eliminates duplicates. What is needed in Soundex is to eliminate consecutive duplicates.

<lang Clojure>

With proper consecutive duplicates elimination

(defn get-code [c]

 (case c
   (\B \F \P \V) 1
   (\C \G \J \K
    \Q \S \X \Z) 2
   (\D \T) 3
   \L 4
   (\M \N) 5
   \R 6
   nil)) ;(\A \E \I \O \U \H \W \Y)

(defn reduce-fn [acc nxt]

(let [next-code (get-code nxt)]
  (if (and (not= next-code (last acc))
           (not (nil? next-code)))
    (conj acc next-code)
    acc)))

(defn soundex [the-word]

 (let [[first-char & the-rest] (.toUpperCase the-word)
       next-code (get-code (first the-rest))]
   (if (nil? next-code)
     (recur (apply str first-char (rest the-rest)))
     (let [soundex-nums (reduce reduce-fn [] the-rest)]
       (apply str first-char (take 3 (conj soundex-nums 0 0 0)))))))</lang>

COBOL

Works with: OpenCOBOL

<lang cobol> **** sndxtest *********************************************

     * Demonstrate the soundex encoding functions.
     ***************************************************************
      Identification division.
      Program-id. sndxtest.
      Data division.
      Working-storage section.
      01 sample-word-list.
          05 sample-words.
              10 filler pic x(15) value "soundex".
              10 filler pic x(15) value "example".
              10 filler pic x(15) value "sownteks".
              10 filler pic x(15) value "ekzampul".
              10 filler pic x(15) value "Euler".
              10 filler pic x(15) value "Gauss".
              10 filler pic x(15) value "Hilbert".
              10 filler pic x(15) value "Knuth".
              10 filler pic x(15) value "Lloyd".
              10 filler pic x(15) value "Lukasiewicz".
              10 filler pic x(15) value "Ellery".
              10 filler pic x(15) value "ghosh".
              10 filler pic x(15) value "Heilbronn".
              10 filler pic x(15) value "Kand".
              10 filler pic x(15) value "Ladd".
              10 filler pic x(15) value "lissajous".
              10 filler pic x(15) value "Wheaton".
              10 filler pic x(15) value "Burroughs".
              10 filler pic x(15) value "burrows".
              10 filler pic x(15) value "O'Hara".
              10 filler pic x(15) value "Washington".
              10 filler pic x(15) value "lee".
              10 filler pic x(15) value "Gutierrez".
              10 filler pic x(15) value "Phister".
              10 filler pic x(15) value "Jackson".
              10 filler pic x(15) value "tymczak".
              10 filler pic x(15) value "Vandeusen".
              10 filler pic x(15) value "Ashcraft".
          05 sample-word redefines sample-words
                        pic x(15) occurs 28 times indexed by wrd-idx.
      01 wrd-code       pic x999.
      Procedure division.
          Perform varying wrd-idx from 1 by 1
          until wrd-idx greater than 28
              call "sndxenc" using
                  by reference sample-word(wrd-idx)
                  by reference wrd-code
              display wrd-code " " sample-word(wrd-idx)
          end-perform.
          Stop run.
      End program sndxtest.
     *** sndxenc ********************************************
     * Given a string return its soundex encoding.
     ***************************************************************
      Identification division.
      Program-id. sndxenc.
      Data division.
      Local-storage section.
      01 str-idx            pic 99.
      01 let-code           pic  9.
      01 prv-let-code       pic  9.
      01 sdx-idx            pic  9  value 1.
      Linkage section.
      01 str-to-encode.
          05 str-first-let  pic x.
          05 str-rest-let   pic x  occurs 14 times.
      01 sdx-code.
          05 sdx-first-let  pic x.
          05 sdx-nums       pic 9  occurs  3 times.
      Procedure division using
          by reference str-to-encode
          by reference sdx-code.
          Perform encode-start thru encode-done.
          Goback.
      Encode-start.
          Move zeros to sdx-code.
          Move function upper-case(str-first-let) to sdx-first-let.
          Call "sndxchar" using
              by reference str-first-let
              by reference let-code.
          Move let-code to prv-let-code.
      Encode-string.
          Perform varying str-idx from 1 by 1
              until str-idx greater than 15
              or str-rest-let(str-idx) = space
              or sdx-idx greater than 3
              call "sndxchar" using
                  by reference str-rest-let(str-idx)
                  by reference let-code
              if let-code not equal 7 then
                  if let-code not equal 0
                  and let-code not equal prv-let-code
                      move let-code to sdx-nums(sdx-idx)
                      add 1 to sdx-idx
                  end-if
                  move let-code to prv-let-code
              end-if
          end-perform.
      Encode-done.
          continue.
      End program sndxenc.


     *** sndxchar **********************************************
     * Given a character, return its soundex encoding.
     * Code 7 is for h or w, which an encoder should ignore when
     * either one separates double letters.
     ***************************************************************
      Identification division.
      Program-id. sndxchar.
      Data division.
      Local-storage section.
      01 lc-chr pic x.
          88 code1 value "b", "f", "p", "v".
          88 code2 value "c", "g", "j", "k", "q", "s", "x", "z".
          88 code3 value "d", "t".
          88 code4 value "l".
          88 code5 value "m", "n".
          88 code6 value "r".
          88 code7 value "h", "w".
      Linkage section.
      01 char-to-encode pic x.
      01 char-sdx-code  pic 9.
      Procedure division using
          by reference char-to-encode
          by reference char-sdx-code.
          Move function lower-case(char-to-encode) to lc-chr.
          If          code1 then move 1 to char-sdx-code
              else if code2 then move 2 to char-sdx-code
              else if code3 then move 3 to char-sdx-code
              else if code4 then move 4 to char-sdx-code
              else if code5 then move 5 to char-sdx-code
              else if code6 then move 6 to char-sdx-code
              else if code7 then move 7 to char-sdx-code
              else               move 0 to char-sdx-code
          end-if.
      End program sndxchar.</lang>
Output:
S532 soundex        
E251 example        
S532 sownteks       
E251 ekzampul       
E460 Euler          
G200 Gauss          
H416 Hilbert        
K530 Knuth          
L300 Lloyd          
L222 Lukasiewicz    
E460 Ellery         
G200 ghosh          
H416 Heilbronn      
K530 Kand           
L300 Ladd           
L222 lissajous      
W350 Wheaton        
B620 Burroughs      
B620 burrows        
O600 O'Hara         
W252 Washington     
L000 lee            
G362 Gutierrez      
P236 Phister        
J250 Jackson        
T522 tymczak        
V532 Vandeusen      
A261 Ashcraft   

Common Lisp

<lang lisp>(defun get-code (c)

 (case c
   ((#\B #\F #\P #\V) #\1)
   ((#\C #\G #\J #\K
     #\Q #\S #\X #\Z) #\2)
   ((#\D #\T) #\3)
   (#\L #\4)
   ((#\M #\N) #\5)
   (#\R #\6)))

(defun soundex (s)

 (if (zerop (length s))
   ""
   (let* ((l (coerce (string-upcase s) 'list))
          (o (list (first l))))
     (loop for c in (rest l)
           for cg = (get-code c) and
           for cp = #\Z then cg
           when (and cg (not (eql cg cp))) do
             (push cg o)
           finally
             (return (subseq (coerce (nreverse `(#\0 #\0 #\0 ,@o)) 'string) 0 4))))))</lang>

Crystal

Translation of: VBScript

<lang ruby># version 0.21.1

def get_code(c : Char)

 case c
 when 'B', 'F', 'P', 'V' 
   "1"
 when 'C', 'G', 'J', 'K', 'Q', 'S', 'X', 'Z'
   "2"
 when 'D', 'T'
   "3"
 when 'L'
   "4"
 when 'M', 'N'
   "5"
 when 'R'
   "6"
 when 'H', 'W'
   "-"
 else 
   ""
 end

end

def soundex(s : String)

 return "" if s == ""
 s = s.upcase
 result = s[0,1] 
 prev = get_code s[0]
 s.lchop.each_char {|c|
   curr = get_code c
   result += curr if curr != "" && curr != "-" && curr != prev
   prev = curr unless curr == "-"
 }
 result.ljust(4, '0')[0, 4]

end

pairs = [

         ["Ashcraft"  , "A261"],
         ["Ashcroft"  , "A261"],
         ["Gauss"     , "G200"],
         ["Ghosh"     , "G200"],
         ["Hilbert"   , "H416"],
         ["Heilbronn" , "H416"],
         ["Lee"       , "L000"],
         ["Lloyd"     , "L300"],
         ["Moses"     , "M220"],
         ["Pfister"   , "P236"],
         ["Robert"    , "R163"],
         ["Rupert"    , "R163"],
         ["Rubin"     , "R150"],
         ["Tymczak"   , "T522"],
         ["Soundex"   , "S532"],
         ["Example"   , "E251"] 
       ]

pairs.each { |pair|

 puts "#{pair[0].ljust(9)} -> #{pair[1]} -> #{soundex(pair[0]) == pair[1]}"

}</lang>

Output:
Ashcraft  -> A261 -> true
Ashcroft  -> A261 -> true
Gauss     -> G200 -> true
Ghosh     -> G200 -> true
Hilbert   -> H416 -> true
Heilbronn -> H416 -> true
Lee       -> L000 -> true
Lloyd     -> L300 -> true
Moses     -> M220 -> true
Pfister   -> P236 -> true
Robert    -> R163 -> true
Rupert    -> R163 -> true
Rubin     -> R150 -> true
Tymczak   -> T522 -> true
Soundex   -> S532 -> true
Example   -> E251 -> true

D

Standard Version

The D standard library (Phobos) contains a soundex function: <lang d>import std.stdio: writeln; import std.string: soundex;

void main() {

   assert(soundex("soundex") == "S532");
   assert(soundex("example") == "E251");
   assert(soundex("ciondecks") == "C532");
   assert(soundex("ekzampul") == "E251");
   assert(soundex("Robert") == "R163");
   assert(soundex("Rupert") == "R163");
   assert(soundex("Rubin") == "R150");
   assert(soundex("Ashcraft") == "A261");
   assert(soundex("Ashcroft") == "A261");
   assert(soundex("Tymczak") == "T522");

}</lang> It works according to this document: http://www.archives.gov/publications/general-info-leaflets/55.html So soundex("Ashcraft") is A-261 instead of A-226.

Alternative Version

This version uses the Wikipedia algorithm, it's long because it contains a ddoc text, design by contract (a long post-condition), sanity asserts, unittests and comments. A quite shorter version may be written that loses the safety net that's necessary in serious coding.

This version uses dynamic heap allocations in some places (replace, toupper, several string join) to allow a higher level style of coding, but this function may also be written to perform zero heap allocations. It may even return a char[4] by value, or use a given buffer like the C version.

<lang d>import std.array, std.string, std.ascii, std.algorithm, std.range;

/** Soundex is a phonetic algorithm for indexing names by sound, as pronounced in English. See: http://en.wikipedia.org/wiki/Soundex

  • /

string soundex(in string name) pure /*nothrow*/ out(result) {

   assert(result.length == 4);
   assert(result[0] == '0' || result[0].isUpper);
   if (name.empty)
       assert(result == "0000");
   immutable charCount = name.filter!isAlpha.walkLength;
   assert((charCount == 0) == (result == "0000"));

} body {

   // Adapted from public domain Python code by Gregory Jorgensen:
   // http://code.activestate.com/recipes/52213/
   // digits holds the soundex values for the alphabet.
   static immutable digits = "01230120022455012623010202";
   string firstChar, result;
   // Translate alpha chars in name to soundex digits.
   foreach (immutable dchar c; name.toUpper) { // Not nothrow.
       if (c.isUpper) {
           if (firstChar.empty)
               firstChar ~= c; // Remember first letter.
           immutable char d = digits[c - 'A'];
           // Duplicate consecutive soundex digits are skipped.
           if (!result.length || d != result.back)
               result ~= d;
       }
   }
   // Return 0000 if the name is empty.
   if (!firstChar.length)
       return "0000";
   // Replace first digit with first alpha character.
   assert(!result.empty);
   result = firstChar ~ result[1 .. $];
   // Remove all 0s from the soundex code.
   result = result.replace("0", "");
   // Return soundex code padded to 4 zeros.
   return (result ~ "0000")[0 .. 4];

} unittest { // Tests of soundex().

   auto tests = [["",         "0000"], ["12346",     "0000"],
                 ["he",       "H000"], ["soundex",   "S532"],
                 ["example",  "E251"], ["ciondecks", "C532"],
                 ["ekzampul", "E251"], ["résumé",  "R250"],
                 ["Robert",   "R163"], ["Rupert",    "R163"],
                 ["Rubin",    "R150"], ["Ashcraft",  "A226"],
                 ["Ashcroft", "A226"]];
   foreach (const pair; tests)
       assert(pair[0].soundex == pair[1]);

}

void main() {}</lang>

Delphi

<lang Delphi> program SoundexDemo;

{$APPTYPE CONSOLE}

uses

 SysUtils,
 StrUtils;

begin

 Writeln(Soundex('Soundex'));
 Writeln(Soundex('Example'));
 Writeln(Soundex('Sownteks'));
 Writeln(Soundex('Ekzampul'));
 Readln;

end. </lang>

Output:
S532
E251
S532
E251

Elixir

Translation of: Erlang

<lang elixir>defmodule Soundex do

 def soundex([]), do: []
 def soundex(str) do
   [head|tail] = String.upcase(str) |> to_char_list
   [head | isoundex(tail, [], todigit(head))]
 end
 
 defp isoundex([], acc, _) do
   case length(acc) do
     n when n == 3 -> Enum.reverse(acc)
     n when n <  3 -> isoundex([], [?0 | acc], :ignore)
     n when n >  3 -> isoundex([], Enum.slice(acc, n-3, n), :ignore)
   end
 end
 defp isoundex([head|tail], acc, lastn) do
   dig = todigit(head)
   if dig != ?0 and dig != lastn do
     isoundex(tail, [dig | acc], dig)
   else
     case head do
       ?H                 -> isoundex(tail, acc, lastn)
       ?W                 -> isoundex(tail, acc, lastn)
       n when n in ?A..?Z -> isoundex(tail, acc, dig)
       _                  -> isoundex(tail, acc, lastn)  # This clause handles non alpha characters
     end
   end
 end
 
 @digits  '01230120022455012623010202'
 defp todigit(chr) do    
   if chr in ?A..?Z, do: Enum.at(@digits, chr - ?A),
                   else: ?0            # Treat non alpha characters as a vowel
 end

end

IO.puts Soundex.soundex("Soundex") IO.puts Soundex.soundex("Example") IO.puts Soundex.soundex("Sownteks") IO.puts Soundex.soundex("Ekzampul")</lang>

Output:
S532
E251
S532
E251

Erlang

This implements the US Census rules, where W and H are ignored but, unlike vowels, are not separators. <lang Erlang>-module(soundex). -export([soundex/1]).

soundex([]) ->

   [];

soundex(Str) ->

   [Head|Tail] = string:to_upper(Str),
   [Head | isoundex(Tail, [], todigit(Head))].

isoundex([], Acc, _) ->

   case length(Acc) of

N when N == 3 -> lists:reverse(Acc); N when N < 3 -> isoundex([], [$0 | Acc], ignore); N when N > 3 -> isoundex([], lists:sublist(Acc, N-2, N), ignore)

   end;

isoundex([Head|Tail], Acc, Lastn) ->

   Dig = todigit(Head),
   case Dig of

Dig when Dig /= $0, Dig /= Lastn -> isoundex(Tail, [Dig | Acc], Dig); _ -> case Head of $H -> isoundex(Tail, Acc, Lastn); $W -> isoundex(Tail, Acc, Lastn); N when N >= $A, N =< $Z -> isoundex(Tail, Acc, Dig); _ -> isoundex(Tail, Acc, Lastn) % This clause handles non alpha characters end

   end.

todigit(Chr) ->

   Digits = "01230120022455012623010202",
   HeadOff = Chr - $A + 1,
   case HeadOff of

N when N > 0, N < 27 -> lists:nth(HeadOff, Digits); _ -> % Treat non alpha characters as a vowel $0

   end.

</lang>

F#

<lang FSharp>module Soundex

let soundex (s : string) =

   let code c = 
       match c with
       | 'B' | 'F' | 'P' | 'V' -> Some('1')
       | 'C' | 'G' | 'J' | 'K' | 'Q' | 'S' | 'X' | 'Z' -> Some('2')
       | 'D' | 'T' -> Some('3')
       | 'L' -> Some('4')
       | 'M' | 'N' -> Some('5')
       | 'R' -> Some('6')
       | _ -> None
   let rec p l = 
       match l with
       | [] -> []
       | x :: y :: tail when (code x) = (code y) -> (p (y :: tail))
       | x :: 'W' :: y :: tail when (code x) = (code y) -> (p (y :: tail))
       | x :: 'H' :: y :: tail when (code x) = (code y) -> (p (y :: tail))
       | x :: tail -> (code x) :: (p tail)
   let chars = 
       match (p (s.ToUpper() |> List.ofSeq)) with
       | [] -> ""
       | head :: tail -> new string((s.[0] :: (tail |> List.filter (fun x -> x.IsSome) |> List.map (fun x -> x.Value))) |> List.toArray)
   chars.PadRight(4, '0').Substring(0, 4)

let test (input, se) =

   printfn "%12s\t%s\t%s" input se (soundex input)

let testCases = [|

   ("Ashcraft", "A261"); ("Ashcroft", "A261"); ("Burroughs", "B620"); ("Burrows", "B620");
   ("Ekzampul", "E251"); ("Example", "E251"); ("Ellery", "E460"); ("Euler", "E460"); 
   ("Ghosh", "G200"); ("Gauss", "G200"); ("Gutierrez", "G362"); ("Heilbronn", "H416"); 
   ("Hilbert", "H416"); ("Jackson", "J250"); ("Kant", "K530"); ("Knuth", "K530");
   ("Lee", "L000"); ("Lukasiewicz", "L222"); ("Lissajous", "L222"); ("Ladd", "L300");
   ("Lloyd", "L300"); ("Moses", "M220"); ("O'Hara", "O600"); ("Pfister", "P236");
   ("Rubin", "R150"); ("Robert", "R163"); ("Rupert", "R163"); ("Soundex", "S532");
   ("Sownteks", "S532"); ("Tymczak", "T522"); ("VanDeusen", "V532"); ("Washington", "W252");
   ("Wheaton", "W350");
   |]

[<EntryPoint>] let main args =

   testCases |> Array.sortBy (fun (_, x) -> x) |> Array.iter test
   System.Console.ReadLine() |> ignore
   0

</lang>

Output:
    Ashcraft    A261    A261
    Ashcroft    A261    A261
   Burroughs    B620    B620
     Burrows    B620    B620
    Ekzampul    E251    E251
     Example    E251    E251
      Ellery    E460    E460
       Euler    E460    E460
       Ghosh    G200    G200
       Gauss    G200    G200
   Gutierrez    G362    G362
   Heilbronn    H416    H416
     Hilbert    H416    H416
     Jackson    J250    J250
        Kant    K530    K530
       Knuth    K530    K530
         Lee    L000    L000
 Lukasiewicz    L222    L222
   Lissajous    L222    L222
        Ladd    L300    L300
       Lloyd    L300    L300
       Moses    M220    M220
      O'Hara    O600    O600
     Pfister    P236    P236
       Rubin    R150    R150
      Robert    R163    R163
      Rupert    R163    R163
     Soundex    S532    S532
    Sownteks    S532    S532
     Tymczak    T522    T522
   VanDeusen    V532    V532
  Washington    W252    W252
     Wheaton    W350    W350

Forth

This implements the US Census rules, where W and H are ignored but, unlike vowels, aren't separators. Further corner cases welcome...

<lang forth>: alpha-table create does> swap 32 or [char] a - 0 max 26 min + 1+ c@ ;

alpha-table soundex-code

 ,"  123 12. 22455 12623 1.2 2 "
  \ ABCDEFGHIJKLMNOPQRSTUVWXYZ
soundex ( name len -- pad len )
 over c@ pad c!                  \ First character verbatim
 pad 1+ 3 [char] 0 fill          \ Pad to four characters with zeros
 1 pad c@ soundex-code  ( count code )
 2swap bounds do
   i c@ soundex-code   ( count code next )
   2dup = if         drop else   \ runs are ignored
   dup [char] . = if drop else   \ W, H don't separate runs of consonants
   dup bl = if        nip else   \ vowels separate consonants but aren't coded
     nip
     2dup swap pad + c!
     swap 1+
     tuck 4 = if leave then
   then then then
 loop
 2drop pad 4 ;

\ Knuth's test cases s" Euler" soundex cr type \ E460 s" Gauss" soundex cr type \ G200 s" Hilbert" soundex cr type \ H416 s" Knuth" soundex cr type \ K530 s" Lloyd" soundex cr type \ L300 s" Lukasiewicz" soundex cr type \ L222 (W test) s" Ellery" soundex cr type \ E460 s" Ghosh" soundex cr type \ G200 s" Heilbronn" soundex cr type \ H416 s" Kant" soundex cr type \ K530 s" Ladd" soundex cr type \ L300 s" Lissajous" soundex cr type \ L222

s" Wheaton" soundex cr type \ W350 s" Ashcraft" soundex cr type \ A261 (H tests) s" Burroughs" soundex cr type \ B620 s" Burrows" soundex cr type \ B620 (W test) (any Welsh names?) s" O'Hara" soundex cr type \ O600 (punctuation test)</lang>

Go

WP article rules, plus my interpretation for input validation. <lang go>package main

import (

   "errors"
   "fmt"
   "unicode"

)

var code = []byte("01230127022455012623017202")

func soundex(s string) (string, error) {

   var sx [4]byte
   var sxi int
   var cx, lastCode byte
   for i, c := range s {
       switch {
       case !unicode.IsLetter(c):
           if c < ' ' || c == 127 {
               return "", errors.New("ASCII control characters disallowed")
           }
           if i == 0 {
               return "", errors.New("initial character must be a letter")
           }
           lastCode = '0'
           continue
       case c >= 'A' && c <= 'Z':
           cx = byte(c - 'A')
       case c >= 'a' && c <= 'z':
           cx = byte(c - 'a')
       default:
           return "", errors.New("non-ASCII letters unsupported")
       }
       // cx is valid letter index at this point
       if i == 0 {
           sx[0] = cx + 'A'
           sxi = 1
           continue
       }
       switch x := code[cx]; x {
       case '7', lastCode:
       case '0':
           lastCode = '0'
       default:
           sx[sxi] = x
           if sxi == 3 {
               return string(sx[:]), nil
           }
           sxi++
           lastCode = x
       }
   }
   if sxi == 0 {
       return "", errors.New("no letters present")
   }
   for ; sxi < 4; sxi++ {
       sx[sxi] = '0'
   }
   return string(sx[:]), nil

}

func main() {

   for _, s := range []string{
       "Robert",   // WP test case = R163
       "Rupert",   // WP test case = R163
       "Rubin",    // WP test case = R150
       "ashcroft", // WP test case = A261
       "ashcraft", // s and c combine across h, t not needed
       "moses",    // s's don't combine across e
       "O'Mally",  // apostrophe allowed, adjacent ll's combine
       "d jay",    // spaces allowed
       "R2-D2",    // digits, hyphen allowed
       "12p2",     // just not in leading position
       "naïve",    // non ASCII disallowed
       "",         // empty string disallowed
       "bump\t",   // ASCII control characters disallowed
   } {
       if x, err := soundex(s); err == nil {
           fmt.Println("soundex", s, "=", x)
       } else {
           fmt.Printf("\"%s\" fail. %s\n", s, err)
       }
   }

}</lang>

Output:
soundex Robert = R163
soundex Rupert = R163
soundex Rubin = R150
soundex ashcroft = A261
soundex ashcraft = A261
soundex moses = M220
soundex O'Mally = O540
soundex d jay = D200
soundex R2-D2 = R300
"12p2" fail. initial character must be a letter
"naïve" fail. non-ASCII letters unsupported
"" fail. no letters present
"bump   " fail. ASCII control characters disallowed

FutureBasic

<lang futurebasic> include "ConsoleWindow"

def tab 12 _soundexNil$ = "0000"

local mode local fn Soundex( codeWord as Str255 ) as Str255 dim as long i,u dim as unsigned char charCode,lastCode dim as Str31 outputStr

outputStr = _soundexNil$

if codeWord[0] = _nil then exit fn

UppercaseStripDiacritics( @codeWord[1], codeWord[0], _smCurrentScript )

outputStr[1] = codeWord[1] charCode = outputStr[1] : gosub "getSoundexCode" lastCode = charCode i = 1 : u = 1

while i <= codeWord[0]

  i++ : charCode = codeWord[i] : gosub "getSoundexCode"
  if charCode > 0 and lastCode <> charCode
     u++ : outputStr[u] = charCode
     if u = 4 then exit while
  end if

lastCode = charCode wend

exit fn

"getSoundexCode"

select charCode case _"B", _"F", _"P", _"V" charCode = _"1" case _"C", _"G", _"J", _"K", _"Q", _"S", _"X", _"Z" charCode = _"2" case _"D", _"T" charCode = _"3" case _"L" charCode = _"4" case _"M", _"N" charCode = _"5" case _"R" charCode = _"6" case else charCode = 0 end select return end fn = outputStr

dim as Str255 nameStr, testName(100) dim as long i

testName(0) = "Smith " testName(1) = "Johnson " testName(2) = "Williams " testName(3) = "Jones " testName(4) = "Brown " testName(5) = "Davis " testName(6) = "Miller " testName(7) = "Wilson " testName(8) = "Moore " testName(9) = "Taylor " testName(10) = "Anderson " testName(11) = "Thomas " testName(12) = "Jackson " testName(13) = "White " testName(14) = "Harris " testName(15) = "Martin " testName(16) = "Thompson " testName(17) = "Garcia " testName(18) = "Martinez " testName(19) = "Robinson " testName(20) = "Clark " testName(21) = "Rodriguez " testName(22) = "Lewis " testName(23) = "Lee " testName(24) = "Walker " testName(25) = "Hall " testName(26) = "Allen " testName(27) = "Young " testName(28) = "Hernandez " testName(29) = "King " testName(30) = "Wright " testName(31) = "Lopez " testName(32) = "Hill " testName(33) = "Scott " testName(34) = "Green " testName(35) = "Adams " testName(36) = "Baker " testName(37) = "Gonzalez " testName(38) = "Nelson " testName(39) = "Carter " testName(40) = "Mitchell " testName(41) = "Perez " testName(42) = "Roberts " testName(43) = "Turner " testName(44) = "Phillips " testName(45) = "Campbell " testName(46) = "Parker " testName(47) = "Evans " testName(48) = "Edwards " testName(49) = "Collins " testName(50) = "Stewart " testName(51) = "Sanchez " testName(52) = "Morris " testName(53) = "Rogers " testName(54) = "Reed " testName(55) = "Cook " testName(56) = "Morgan " testName(57) = "Bell " testName(58) = "Murphy " testName(59) = "Bailey " testName(60) = "Rivera " testName(61) = "Cooper " testName(62) = "Richardson " testName(63) = "Cox " testName(64) = "Howard " testName(65) = "Ward " testName(66) = "Torres " testName(67) = "Peterson " testName(68) = "Gray " testName(69) = "Ramirez " testName(70) = "James " testName(71) = "Watson " testName(72) = "Brooks " testName(73) = "Kelly " testName(74) = "Sanders " testName(75) = "Price " testName(76) = "Bennett " testName(77) = "Wood " testName(78) = "Barnes " testName(79) = "Ross " testName(80) = "Henderson " testName(81) = "Coleman " testName(82) = "Jenkins " testName(83) = "Perry " testName(84) = "Powell " testName(85) = "Long " testName(86) = "Patterson " testName(87) = "Hughes " testName(88) = "Flores " testName(89) = "Washington " testName(90) = "Butler " testName(91) = "Simmons " testName(92) = "Foster " testName(93) = "Gonzales " testName(94) = "Bryant " testName(95) = "Alexander " testName(96) = "Russell " testName(97) = "Griffin " testName(98) = "Diaz " testName(99) = "Hayes "

print "Soundex codes for 100 popular American surnames:" for i = 0 to 99

  nameStr = testName(i)
  print nameStr, "= "; fn Soundex( nameStr )

next

print print "Soundex codes for similar sounding names:"

print " Stuart = "; fn Soundex( "Stuart" ) print "Stewart = "; fn Soundex( "Stewart" ) print "Steward = "; fn Soundex( "Steward" ) print " Seward = "; fn Soundex( "Seward" )

</lang>

Output:

Soundex codes for 100 popular American surnames:
Smith       = S530
Johnson     = J525
Williams    = W452
Jones       = J520
Brown       = B650
Davis       = D120
Miller      = M460
Wilson      = W425
Moore       = M600
Taylor      = T460
Anderson    = A536
Thomas      = T520
Jackson     = J250
White       = W300
Harris      = H620
Martin      = M635
Thompson    = T512
Garcia      = G620
Martinez    = M635
Robinson    = R152
Clark       = C462
Rodriguez   = R362
Lewis       = L200
Lee         = L000
Walker      = W426
Hall        = H400
Allen       = A450
Young       = Y520
Hernandez   = H655
King        = K520
Wright      = W623
Lopez       = L120
Hill        = H400
Scott       = S300
Green       = G650
Adams       = A352
Baker       = B260
Gonzalez    = G524
Nelson      = N425
Carter      = C636
Mitchell    = M324
Perez       = P620
Roberts     = R163
Turner      = T656
Phillips    = P412
Campbell    = C514
Parker      = P626
Evans       = E152
Edwards     = E363
Collins     = C452
Stewart     = S363
Sanchez     = S522
Morris      = M620
Rogers      = R262
Reed        = R300
Cook        = C200
Morgan      = M625
Bell        = B400
Murphy      = M610
Bailey      = B400
Rivera      = R160
Cooper      = C160
Richardson  = R263
Cox         = C200
Howard      = H630
Ward        = W630
Torres      = T620
Peterson    = P362
Gray        = G600
Ramirez     = R562
James       = J520
Watson      = W325
Brooks      = B620
Kelly       = K400
Sanders     = S536
Price       = P620
Bennett     = B530
Wood        = W300
Barnes      = B652
Ross        = R200
Henderson   = H536
Coleman     = C455
Jenkins     = J525
Perry       = P600
Powell      = P400
Long        = L520
Patterson   = P362
Hughes      = H220
Flores      = F462
Washington  = W252
Butler      = B346
Simmons     = S552
Foster      = F236
Gonzales    = G524
Bryant      = B653
Alexander   = A425
Russell     = R240
Griffin     = G615
Diaz        = D200
Hayes       = H200

Soundex codes for similar sounding names:
 Stuart = S363
Stewart = S363
Steward = S363
 Seward = S630

Groovy

<lang groovy> def soundex(s) {

   def code = ""
   def lookup = [
      B : 1, F : 1, P : 1, V : 1,
      C : 2, G : 2, J : 2, K : 2, Q : 2, S : 2, X : 2, Z : 2,
      D : 3, T : 3,
      L : 4,
      M : 5, N : 5,
      R : 6
   ]
   s[1..-1].toUpperCase().inject(7) { lastCode, letter ->
       def letterCode = lookup[letter]
       if(letterCode && letterCode != lastCode) {
           code += letterCode
       }
   }
   return "${s[0]}${code}0000"[0..3]

}

println(soundex("Soundex")) println(soundex("Sownteks")) println(soundex("Example")) println(soundex("Ekzampul")) </lang>

Haskell

<lang haskell>import Text.PhoneticCode.Soundex import Control.Arrow</lang> Example: <lang haskell>*Main> mapM_ print $ map (id &&& soundexSimple) ["Soundex", "Example", "Sownteks", "Ekzampul"] ("Soundex","S532") ("Example","E251") ("Sownteks","S532") ("Ekzampul","E251")</lang>

Icon and Unicon

<lang icon>procedure main(arglist) # computes soundex of each argument every write(x := !arglist, " => ",soundex(x)) end

procedure soundex(name)

  local  dig,i,x
  static con
  initial {                                   # construct mapping x[i] => i all else .
     x := ["bfpv","cgjkqsxz","dt","l","mn","r"]
     every ( dig := con := "") ||:= repl(i := 1 to *x,*x[i]) do con ||:= x[i]
     con := map(map(&lcase,con,dig),&lcase,repl(".",*&lcase))
     } 
 
  name := map(name)                           # lower case
  name[1] := map(name[1],&lcase,&ucase)       # upper case 1st
  name := map(name,&lcase,con)                # map cons
  every x := !"123456" do
      while name[find(x||x,name)+:2] := x     # kill duplicates
  while name[upto('.',name)] := ""            # kill .
  return left(name,4,"0")                     

end</lang>

implements soundex. The above version is an adaptation of that procedure

J

Solution <lang j>removeDups =: {.;.1~ (1 , }. ~: }: ) codes =: ;: 'BFPV CGJKQSXZ DT L MN R HW'

soundex =: 3 : 0

if. 0=# k=.toupper y do. '0' return. end.
({.k), ,": ,. 3 {. 0-.~ }. removeDups 7 0:`(I.@:=)`]} , k >:@I.@:(e. &>)"0 _ codes

)</lang> Usage <lang j>names=: 'Lloyd Woolcock Donnell Baragwanath Williams Ashcroft Euler Ellery Gauss Ghosh Hilbert Heilbronn Knuth Kant Ladd Lukasiewicz Lissajous' soundexNames=: 'L300 W422 D540 B625 W452 A226 E460 E460 G200 G200 H416 H416 K530 K530 L300 L222 L222'

  soundex &> ;: names

L300 W422 D540 B625 W452 ....</lang> Test <lang j> soundexNames-:(soundex &.>) &. ;: names 1</lang>

Java

Translation of: VBScript

<lang java>public static void main(String[] args){

   System.out.println(soundex("Soundex"));
   System.out.println(soundex("Example"));
   System.out.println(soundex("Sownteks"));
   System.out.println(soundex("Ekzampul"));
 }

private static String getCode(char c){

 switch(c){
   case 'B': case 'F': case 'P': case 'V':
     return "1";
   case 'C': case 'G': case 'J': case 'K':
   case 'Q': case 'S': case 'X': case 'Z':
     return "2";
   case 'D': case 'T':
     return "3";
   case 'L':
     return "4";
   case 'M': case 'N':
     return "5";
   case 'R':
     return "6";
   default:
     return "";
 }

}

public static String soundex(String s){

 String code, previous, soundex;
 code = s.toUpperCase().charAt(0) + "";
 previous = "7";
 for(int i = 1;i < s.length();i++){
   String current = getCode(s.toUpperCase().charAt(i));
   if(current.length() > 0 && !current.equals(previous)){
     code = code + current;
   }
   previous = current;
 }
 soundex = (code + "0000").substring(0, 4);
 return soundex;

}</lang>

Output:
S532
E251
S532
E251

JavaScript

ES5

Version w/o RegExp

<lang javascript>var soundex = function (s) {

    var a = s.toLowerCase().split()
        f = a.shift(),
        r = ,
        codes = {
            a: , e: , i: , o: , u: ,
            b: 1, f: 1, p: 1, v: 1,
            c: 2, g: 2, j: 2, k: 2, q: 2, s: 2, x: 2, z: 2,
            d: 3, t: 3,
            l: 4,
            m: 5, n: 5,
            r: 6
        };

    r = f +
        a
        .map(function (v, i, a) { return codes[v] })
        .filter(function (v, i, a) { return ((i === 0) ? v !== codes[f] : v !== a[i - 1]); })
        .join();

    return (r + '000').slice(0, 4).toUpperCase();

};

var tests = {

 "Soundex":     "S532",
 "Example":     "E251",
 "Sownteks":    "S532",
 "Ekzampul":    "E251",
 "Euler":       "E460",
 "Gauss":       "G200",
 "Hilbert":     "H416",
 "Knuth":       "K530",
 "Lloyd":       "L300",
 "Lukasiewicz": "L222",
 "Ellery":      "E460",
 "Ghosh":       "G200",
 "Heilbronn":   "H416",
 "Kant":        "K530",
 "Ladd":        "L300",
 "Lissajous":   "L222",
 "Wheaton":     "W350",
 "Ashcraft":    "A226",
 "Burroughs":   "B622",
 "Burrows":     "B620",
 "O'Hara":      "O600"
 };

for (var i in tests)

 if (tests.hasOwnProperty(i)) {
   console.log(
     i +
     '    \t' +
     tests[i] +
     '\t' +
     soundex(i) +
     '\t' +
     (soundex(i) === tests[i])
   );

}

// Soundex S532 S532 true // Example E251 E251 true // Sownteks S532 S532 true // Ekzampul E251 E251 true // Euler E460 E460 true // Gauss G200 G200 true // Hilbert H416 H416 true // Knuth K530 K530 true // Lloyd L300 L300 true // Lukasiewicz L222 L222 true // Ellery E460 E460 true // Ghosh G200 G200 true // Heilbronn H416 H416 true // Kant K530 K530 true // Ladd L300 L300 true // Lissajous L222 L222 true // Wheaton W350 W350 true // Ashcraft A226 A226 true // Burroughs B622 B622 true // Burrows B620 B620 true // O'Hara O600 O600 true</lang>


Extended version w/ RegExp

Note: This version differs from the one above in the following way. According to U.S. National Archives Website, consecutive consonants which map to the same code are not condensed to a single occurrence of the code if they are separated by vowels, but separating W and H do not thus intervene. Therefore Ashcraft is coded A261 and Burroughs is coded B620 rather than A226 and B622

<lang javascript> function soundex(t) {

 t = t.toUpperCase().replace(/[^A-Z]/g, );
 return (t[0] || '0') + t.replace(/[HW]/g, )
   .replace(/[BFPV]/g, '1')
   .replace(/[CGJKQSXZ]/g, '2')
   .replace(/[DT]/g, '3')
   .replace(/[L]/g, '4')
   .replace(/[MN]/g, '5')
   .replace(/[R]/g, '6')
   .replace(/(.)\1+/g, '$1')
   .substr(1)
   .replace(/[AEOIUHWY]/g, )
   .concat('000')
   .substr(0, 3);

}

// tests [ ["Example", "E251"], ["Sownteks", "S532"], ["Lloyd", "L300"], ["12346", "0000"],

["4-H", "H000"], ["Ashcraft", "A261"], ["Ashcroft", "A261"], ["auerbach", "A612"],
["bar", "B600"], ["barre", "B600"], ["Baragwanath", "B625"], ["Burroughs", "B620"],
["Burrows", "B620"], ["C.I.A.", "C000"], ["coöp", "C100"], ["D-day", "D000"],
["d jay", "D200"], ["de la Rosa", "D462"], ["Donnell", "D540"], ["Dracula", "D624"],
["Drakula", "D624"], ["Du Pont", "D153"], ["Ekzampul", "E251"], ["example", "E251"],
["Ellery", "E460"], ["Euler", "E460"], ["F.B.I.", "F000"], ["Gauss", "G200"],
["Ghosh", "G200"], ["Gutierrez", "G362"], ["he", "H000"], ["Heilbronn", "H416"],
["Hilbert", "H416"], ["Jackson", "J250"], ["Johnny", "J500"], ["Jonny", "J500"],
["Kant", "K530"], ["Knuth", "K530"], ["Ladd", "L300"], ["Lloyd", "L300"],
["Lee", "L000"], ["Lissajous", "L222"], ["Lukasiewicz", "L222"], ["naïve", "N100"],
["Miller", "M460"], ["Moses", "M220"], ["Moskowitz", "M232"], ["Moskovitz", "M213"],
["O'Conner", "O256"], ["O'Connor", "O256"], ["O'Hara", "O600"], ["O'Mally", "O540"],
["Peters", "P362"], ["Peterson", "P362"], ["Pfister", "P236"], ["R2-D2", "R300"],
["rÄ≈sumÅ∙", "R250"], ["Robert", "R163"], ["Rupert", "R163"], ["Rubin", "R150"],
["Soundex", "S532"], ["sownteks", "S532"], ["Swhgler", "S460"], ["'til", "T400"],
["Tymczak", "T522"], ["Uhrbach", "U612"], ["Van de Graaff", "V532"],
["VanDeusen", "V532"], ["Washington", "W252"], ["Wheaton", "W350"],
["Williams", "W452"], ["Woolcock", "W422"]

].forEach(function(v) {

 var a = v[0], t = v[1], d = soundex(a);
  if (d !== t) {
   console.log('soundex("' + a + '") was ' + d + ' should be ' + t);
 }

}); </lang>

ES6

Allowing for both Simple Soundex (first example above) and NARA Soundex (second example above) (Reusing set of tests from second contribution)

<lang JavaScript>(() => {

   'use strict';
   // Simple Soundex or NARA Soundex (if blnNara = true)
   // soundex :: Bool -> String -> String
   const soundex = (blnNara, name) => {
       // code :: Char -> Char
       const code = c => ['AEIOU', 'BFPV', 'CGJKQSXZ', 'DT', 'L', 'MN', 'R', 'HW']
           .reduce((a, x, i) =>
               a ? a : (x.indexOf(c) !== -1 ? i.toString() : a), );
       // isAlpha :: Char -> Boolean
       const isAlpha = c => {
           const d = c.charCodeAt(0);
           return d > 64 && d < 91;
       };
       const s = name.toUpperCase()
           .split()
           .filter(isAlpha);
       return (s[0] || '0') +
           s.map(code)
           .join()
           .replace(/7/g, blnNara ?  : '7')
           .replace(/(.)\1+/g, '$1')
           .substr(1)
           .replace(/[07]/g, )
           .concat('000')
           .substr(0, 3);
   };
   // curry :: ((a, b) -> c) -> a -> b -> c
   const curry = f => a => b => f(a, b),
       [simpleSoundex, naraSoundex] = [false, true]
       .map(bln => curry(soundex)(bln));
   // TEST
   return [
       ["Example", "E251"],
       ["Sownteks", "S532"],
       ["Lloyd", "L300"],
       ["12346", "0000"],
       ["4-H", "H000"],
       ["Ashcraft", "A261"],
       ["Ashcroft", "A261"],
       ["auerbach", "A612"],
       ["bar", "B600"],
       ["barre", "B600"],
       ["Baragwanath", "B625"],
       ["Burroughs", "B620"],
       ["Burrows", "B620"],
       ["C.I.A.", "C000"],
       ["coöp", "C100"],
       ["D-day", "D000"],
       ["d jay", "D200"],
       ["de la Rosa", "D462"],
       ["Donnell", "D540"],
       ["Dracula", "D624"],
       ["Drakula", "D624"],
       ["Du Pont", "D153"],
       ["Ekzampul", "E251"],
       ["example", "E251"],
       ["Ellery", "E460"],
       ["Euler", "E460"],
       ["F.B.I.", "F000"],
       ["Gauss", "G200"],
       ["Ghosh", "G200"],
       ["Gutierrez", "G362"],
       ["he", "H000"],
       ["Heilbronn", "H416"],
       ["Hilbert", "H416"],
       ["Jackson", "J250"],
       ["Johnny", "J500"],
       ["Jonny", "J500"],
       ["Kant", "K530"],
       ["Knuth", "K530"],
       ["Ladd", "L300"],
       ["Lloyd", "L300"],
       ["Lee", "L000"],
       ["Lissajous", "L222"],
       ["Lukasiewicz", "L222"],
       ["naïve", "N100"],
       ["Miller", "M460"],
       ["Moses", "M220"],
       ["Moskowitz", "M232"],
       ["Moskovitz", "M213"],
       ["O'Conner", "O256"],
       ["O'Connor", "O256"],
       ["O'Hara", "O600"],
       ["O'Mally", "O540"],
       ["Peters", "P362"],
       ["Peterson", "P362"],
       ["Pfister", "P236"],
       ["R2-D2", "R300"],
       ["rÄ≈sumÅ∙", "R250"],
       ["Robert", "R163"],
       ["Rupert", "R163"],
       ["Rubin", "R150"],
       ["Soundex", "S532"],
       ["sownteks", "S532"],
       ["Swhgler", "S460"],
       ["'til", "T400"],
       ["Tymczak", "T522"],
       ["Uhrbach", "U612"],
       ["Van de Graaff", "V532"],
       ["VanDeusen", "V532"],
       ["Washington", "W252"],
       ["Wheaton", "W350"],
       ["Williams", "W452"],
       ["Woolcock", "W422"]
   ].reduce((a, [name, naraCode]) => {
       const naraTest = naraSoundex(name),
           simpleTest = simpleSoundex(name);
       const logNara = naraTest !== naraCode ? (
               `${name} was ${naraTest} should be ${naraCode}`
           ) : ,
           logDelta = (naraTest !== simpleTest ? (
               `${name} -> NARA: ${naraTest} vs Simple: ${simpleTest}`
           ) : );
       return logNara.length || logDelta.length ? (
           a + [logNara, logDelta].join('\n')
       ) : a;
   }, );

})();</lang>

Output:
Ashcraft -> NARA: A261 vs Simple: A226
Ashcroft -> NARA: A261 vs Simple: A226
Burroughs -> NARA: B620 vs Simple: B622
Swhgler -> NARA: S460 vs Simple: S246

Kotlin

Translation of: VBScript

<lang scala>// version 1.1.2

fun getCode(c: Char) = when (c) {

   'B', 'F', 'P', 'V' -> "1"
   'C', 'G', 'J', 'K', 'Q', 'S', 'X', 'Z' -> "2"
   'D', 'T' -> "3"
   'L' -> "4"
   'M', 'N' -> "5"
   'R' -> "6"
   'H', 'W' -> "-"
   else -> ""

}

fun soundex(s: String): String {

   if (s == "") return ""
   val sb = StringBuilder().append(s[0].toUpperCase())
   var prev = getCode(sb[0])
   for (i in 1 until s.length) {
       val curr = getCode(s[i].toUpperCase())
       if (curr != "" && curr != "-" && curr != prev) sb.append(curr)
       if (curr != "-") prev = curr
   }
   return sb.toString().padEnd(4, '0').take(4)

}

fun main(args: Array<String>) {

   val pairs = arrayOf(
       "Ashcraft"  to "A261",
       "Ashcroft"  to "A261",
       "Gauss"     to "G200",
       "Ghosh"     to "G200",
       "Hilbert"   to "H416",
       "Heilbronn" to "H416",
       "Lee"       to "L000",
       "Lloyd"     to "L300",
       "Moses"     to "M220",
       "Pfister"   to "P236",
       "Robert"    to "R163",
       "Rupert"    to "R163",
       "Rubin"     to "R150",
       "Tymczak"   to "T522",
       "Soundex"   to "S532",
       "Example"   to "E251"
   )
   for (pair in pairs) {
       println("${pair.first.padEnd(9)} -> ${pair.second} -> ${soundex(pair.first) == pair.second}")
   }

}</lang>

Output:
Ashcraft  -> A261 -> true
Ashcroft  -> A261 -> true
Gauss     -> G200 -> true
Ghosh     -> G200 -> true
Hilbert   -> H416 -> true
Heilbronn -> H416 -> true
Lee       -> L000 -> true
Lloyd     -> L300 -> true
Moses     -> M220 -> true
Pfister   -> P236 -> true
Robert    -> R163 -> true
Rupert    -> R163 -> true
Rubin     -> R150 -> true
Tymczak   -> T522 -> true
Soundex   -> S532 -> true
Example   -> E251 -> true

Mathematica

<lang Mathematica>Soundex[ input_ ] := Module[{x = input, head, body}, {head, body} = {First@#, Rest@#}&@ToLowerCase@Characters@x; body = (Select[body, FreeQ[Characters["aeiouyhw"],#]&] /. {("b"|"f"|"p"|"v")->1, ("c"|"g"|"j"|"k"|"q"|"s"|"x"|"z")->2, ("d"|"t")->3,"l"->4 ,("m"|"n")->5, "r"->6}); If[Length[body] < 3,

body = PadRight[body, 3],
body = DeleteDuplicates[body]

]; StringJoin @@ ToString /@ PrependTo[ body1 ;; 3, ToUpperCase@head]]</lang> Example usage:

Map[Soundex,{"Soundex", "Sownteks", "Example", "Ekzampul"}]
-> {S532, S532, E251, E251}

MUMPS

<lang MUMPS>SOUNDEX(X,NARA=0)

;Converts a string to its Soundex value.
;Empty strings return "0000". Non-alphabetic ASCII characters are ignored.
;X is the name to be converted to Soundex
;NARA is a flag, defaulting to zero, for which implementation to perform.
;If NARA is 0, do what seems to be the Knuth implementation
;If NARA is a positive integer, do the NARA implementation.
; This varies the soundex rule for "W" and "H", and adds variants for prefixed names separated by carets.
; http://www.archives.gov/publications/general-info-leaflets/55-census.html
;Y is the string to be returned
;UP is the list of upper case letters
;LO is the list of lower case letters
;PREFIX is a list of prefixes to be stripped off
;X1 is the upper case version of X
;X2 is the name without a prefix
;Y2 is the soundex of a name without a prefix
;C is a loop variable
;DX is a list of Soundex values, in alphabetical order. Underscores are used for the NARA variation letters
;XD is a partially processed translation of X into soundex values
NEW Y,UP,LO,PREFIX,X1,X2,Y2,C,DX,XD
SET UP="ABCDEFGHIJKLMNOPQRSTUVWXYZ" ;Upper case characters
SET LO="abcdefghijklmnopqrstuvwxyz" ;Lower case characters
SET DX=" 123 12_ 22455 12623 1_2 2" ;Soundex values
SET PREFIX="VAN^CO^DE^LA^LE" ;Prefixes that could create an alternate soundex value
SET Y="" ;Y is the value to be returned
SET X1=$TRANSLATE(X,LO,UP) ;Make local copy, and force all letters to be upper case
SET XD=$TRANSLATE(X1,UP,DX) ;Soundex values for string
;
SET Y=$EXTRACT(X1,1,1) ;Get first character
FOR C=2:1:$LENGTH(X1) QUIT:$L(Y)>=4  DO
. ;ignore doubled letters OR and side-by-side soundex values OR same soundex on either side of "H" or "W"
. QUIT:($EXTRACT(X1,C,C)=$EXTRACT(X1,C-1,C-1))
. QUIT:($EXTRACT(XD,C,C)=$EXTRACT(XD,C-1,C-1))
. ;ignore non-alphabetic characters
. QUIT:UP'[($EXTRACT(X1,C,C))
. QUIT:NARA&(($EXTRACT(XD,C-1,C-1)="_")&(C>2))&($EXTRACT(XD,C,C)=$EXTRACT(XD,C-2,C-2))
. QUIT:" _"[$EXTRACT(XD,C,C)
. SET Y=Y_$EXTRACT(XD,C,C)
; Pad with "0" so string length is 4
IF $LENGTH(Y)<4 FOR C=$L(Y):1:3 SET Y=Y_"0"
IF NARA DO
. FOR C=1:1:$LENGTH(PREFIX,"^") DO
. . IF $EXTRACT(X1,1,$LENGTH($PIECE(PREFIX,"^",C)))=$PIECE(PREFIX,"^",C) DO
. . . ;Take off the prefix, and any leading spaces
. . . SET X2=$EXTRACT(X1,$LENGTH($PIECE(PREFIX,"^",C))+1,$LENGTH(X1)-$PIECE(PREFIX,"^",C)) FOR  QUIT:UP[$E(X2,1,1)  SET X2=$E(X2,2,$L(X2))
. . . SET Y2=$$SOUNDEX(X2,NARA) SET Y=Y_"^"_Y2
KILL UP,LO,PREFIX,X1,X2,Y2,C,DX,XD
QUIT Y

</lang>

Examples:

USER>W $$SOUNDEX^SOUNDEX("")
0000
USER>W $$SOUNDEX^SOUNDEX("ASHCROFT")
A226
USER>W $$SOUNDEX^SOUNDEX("ASHCROFT",1)
A261
USER>W $$SOUNDEX^SOUNDEX("EULER")
E460
USER>W $$SOUNDEX^SOUNDEX("O'HARA")
O600
USER>W $$SOUNDEX^SOUNDEX("naïve")
N100
USER>W $$SOUNDEX^SOUNDEX("Moses")
M220
USER>W $$SOUNDEX^SOUNDEX("Omalley")
O540
USER>W $$SOUNDEX^SOUNDEX("O'Malley")
O540
USER>W $$SOUNDEX^SOUNDEX("Delarosa")
D462
USER>W $$SOUNDEX^SOUNDEX("Delarosa",1)
D462^L620^R200
USER>W $$SOUNDEX^SOUNDEX("De la Rosa")
D462
USER>W $$SOUNDEX^SOUNDEX("de la Rosa",1)
D462^L620^R200
USER>W $$SOUNDEX^SOUNDEX("Van de Graaff")
V532
USER>W $$SOUNDEX^SOUNDEX("Van de Graaff",1)
V532^D261^G610

There's just one small problem...

USER>W $$SOUNDEX^SOUNDEX("fish")
F200
USER>W $$SOUNDEX^SOUNDEX("ghoti")
G300

OCaml

Here is an implementation:

<lang ocaml>let c2d = function

 | 'B' | 'F' | 'P' | 'V' -> "1"
 | 'C' | 'G' | 'J' | 'K' | 'Q' | 'S' | 'X' | 'Z' -> "2"
 | 'D' | 'T' -> "3"
 | 'L' -> "4"
 | 'M' | 'N' -> "5"
 | 'R' -> "6"
 | _ -> ""

let rec dbl acc = function

 | [] -> (List.rev acc)
 | [c] -> List.rev(c::acc)
 | c1::(c2::_ as tl) ->
     if c1 = c2
     then dbl acc tl
     else dbl (c1::acc) tl

let pad s =

 match String.length s with
 | 0 -> s ^ "000"
 | 1 -> s ^ "00"
 | 2 -> s ^ "0"
 | 3 -> s
 | _ -> String.sub s 0 3

let soundex_aux rem =

 pad(String.concat "" (dbl [] (List.map c2d rem)))

let soundex s =

 let s = String.uppercase s in
 let cl = ref [] in
 String.iter (fun c -> cl := c :: !cl) s;
 match dbl [] (List.rev !cl) with
 | c::rem -> (String.make 1 c) ^ (soundex_aux rem)
 | [] -> invalid_arg "soundex"</lang>

Test our implementation:

<lang ocaml>let tests = [

 "Soundex",     "S532";
 "Example",     "E251";
 "Sownteks",    "S532";
 "Ekzampul",    "E251";
 "Euler",       "E460";
 "Gauss",       "G200";
 "Hilbert",     "H416";
 "Knuth",       "K530";
 "Lloyd",       "L300";
 "Lukasiewicz", "L222";
 "Ellery",      "E460";
 "Ghosh",       "G200";
 "Heilbronn",   "H416";
 "Kant",        "K530";
 "Ladd",        "L300";
 "Lissajous",   "L222";
 "Wheaton",     "W350";
 "Ashcraft",    "A226";
 "Burroughs",   "B622";
 "Burrows",     "B620";
 "O'Hara",      "O600";
 ]

let () =

 print_endline " Word   \t Code  Found Status";
 List.iter (fun (word, code1) ->
   let code2 = soundex word in
   let status = if code1 = code2 then "OK " else "Arg" in
   Printf.printf " \"%s\" \t %s  %s  %s\n" word code1 code2 status
 ) tests</lang>
Output:
 Word            Code  Found Status
 "Soundex"       S532  S532  OK 
 "Example"       E251  E251  OK 
 "Sownteks"      S532  S532  OK 
 "Ekzampul"      E251  E251  OK 
 "Euler"         E460  E460  OK 
 "Gauss"         G200  G200  OK 
 "Hilbert"       H416  H416  OK 
 "Knuth"         K530  K530  OK 
 "Lloyd"         L300  L300  OK 
 "Lukasiewicz"   L222  L222  OK 
 "Ellery"        E460  E460  OK 
 "Ghosh"         G200  G200  OK 
 "Heilbronn"     H416  H416  OK 
 "Kant"          K530  K530  OK 
 "Ladd"          L300  L300  OK 
 "Lissajous"     L222  L222  OK 
 "Wheaton"       W350  W350  OK 
 "Ashcraft"      A226  A226  OK 
 "Burroughs"     B622  B622  OK 
 "Burrows"       B620  B620  OK 
 "O'Hara"        O600  O600  OK

See Soundex/OCaml for a version that can switch the language (English, French...) with a type which definition is hidden in the interface.

Pascal

Works with: Free Pascal version 2.6.2

<lang Pascal>program Soundex;

{$mode objfpc}{$H+}

uses

 {$IFDEF UNIX}{$IFDEF UseCThreads}
 cthreads,
 {$ENDIF}{$ENDIF}
  SysUtils;

type

 TLang=(en,fr,de);

const

  Examples : array[1..16, 1..2] of string =
    (('Ashcraft', 'A261')
    ,('Ashcroft', 'A261')
    ,('Gauss', 'G200')
    ,('Ghosh', 'G200')
    ,('Hilbert', 'H416')
    ,('Heilbronn', 'H416')
    ,('Lee', 'L000')
    ,('Lloyd', 'L300')
    ,('Moses', 'M220')
    ,('Pfister', 'P236')
    ,('Robert', 'R163')
    ,('Rupert', 'R163')
    ,('Rubin', 'R150')
    ,('Tymczak', 'T522')
    ,('Soundex', 'S532')
    ,('Example', 'E251')
    );

// For Ansi Str function Soundex(Value: String; Lang: TLang) : String; const

 // Thx to WP.
 Map: array[TLang, 0..2] of String =(
   // Deals with accented, to improve
   ('abcdefghijklmnopqrstuvwxyz'
   ,'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
   ,' 123 12- 22455 12623 1-2 2'),
   ('aàâäbcçdeéèêëfghiîjklmnoöôpqrstuùûüvwxyz' // all chars with accented
   ,'AAAABCCDEEEEEFGHIIJKLMNOOOPQRSTUUUUVWXYZ' // uppercased
   ,' 123 97- 72455 12683 9-8 8'),             // coding
   ('abcdefghijklmnopqrstuvwxyz'
   ,'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
   ,' 123 12- 22455 12623 1-2 2')
   );

var

 i: Integer;
 c, cOld: Char;
 function Normalize(const s: string): string;
 var
   c: Char;
   p: Integer;
 begin
   result := ;
   for c in LowerCase(s) do
   begin
     p := Pos(c, Map[Lang,0]);
     // unmapped chars are ignored
     if p > 0 then
       Result := Result + Map[Lang, 1][p];
   end;
 End;
 function GetCode(c: Char): Char;
 begin
   Result := Map[Lang, 2][Ord(c)-Ord('A')+1];
 End;

begin

 Value := Trim(Value);
 if Value =  then
 begin
   Result := '0000';
   exit;
 end;
 Value := Normalize(Value);
 Result := Value[1];
 cOld := GetCode(Value[1]);
 for i := 2 to length(Value) do
 begin
   c := GetCode(Value[i]);
   if (c <> ' ') and (c <> '-') and (c <> cOld) then
     Result := Result + c;
   if c <> '-' then
     cOld := c;
 end;
 Result := Copy(Result+'0000', 1, 4);

End;

const

 Status : array[boolean] of string = ('KO', 'OK');

var

 Found: String;
 tab: array[1..2] of String;

begin

 WriteLn('Word                : Code   Found   Status');
 for tab in Examples do
 begin
   Found := Soundex(tab[1], en);
   WriteLn(Format('%-20s: %s   %s    %s',[tab[1], tab[2], Found, Status[Found = tab[2]]]))
 end;
 ReadLn;

End.</lang>

Output:
Word                : Code   Found   Status
Ashcraft            : A261   A261    OK
Ashcroft            : A261   A261    OK
Gauss               : G200   G200    OK
Ghosh               : G200   G200    OK
Hilbert             : H416   H416    OK
Heilbronn           : H416   H416    OK
Lee                 : L000   L000    OK
Lloyd               : L300   L300    OK
Moses               : M220   M220    OK
Pfister             : P236   P236    OK
Robert              : R163   R163    OK
Rupert              : R163   R163    OK
Rubin               : R150   R150    OK
Tymczak             : T522   T522    OK
Soundex             : S532   S532    OK
Example             : E251   E251    OK

Perl

The Text::Soundex core module supports various soundex algorithms. <lang perl>use Text::Soundex; print soundex("Soundex"), "\n"; # S532 print soundex("Example"), "\n"; # E251 print soundex("Sownteks"), "\n"; # S532 print soundex("Ekzampul"), "\n"; # E251</lang>

Perl 6

US census algorithm, so "Ashcraft" and "Burroughs" adjusted to match. We fake up a first consonant in some cases to make up for the fact that we always trim the first numeric code (so that the 'l' of 'Lloyd' is properly deleted). <lang perl6>sub soundex ($name --> Str) {

   my $first = substr($name,0,1).uc;
   gather {
       take $first;
       my $fakefirst = ;
       $fakefirst = "de " if $first ~~ /^ <[AEIOUWH]> /;
       "$fakefirst$name".lc.trans('wh' => ) ~~ /
           ^
           [
               [
               | <[ bfpv     ]>+ { take 1 }
               | <[ cgjkqsxz ]>+ { take 2 }
               | <[ dt       ]>+ { take 3 }
               | <[ l        ]>+ { take 4 }
               | <[ mn       ]>+ { take 5 }
               | <[ r        ]>+ { take 6 }
               ]
           || .
           ]+
           $ { take 0,0,0 }
       /;
   }.flat.[0,2,3,4].join;

}

for < Soundex S532

     Example     E251
     Sownteks    S532
     Ekzampul    E251
     Euler       E460
     Gauss       G200
     Hilbert     H416
     Knuth       K530
     Lloyd       L300
     Lukasiewicz L222
     Ellery      E460
     Ghosh       G200
     Heilbronn   H416
     Kant        K530
     Ladd        L300
     Lissajous   L222
     Wheaton     W350
     Ashcraft    A261
     Burroughs   B620
     Burrows     B620
     O'Hara      O600 >

-> $n, $s {

   my $s2 = soundex($n);
   say $n.fmt("%16s "), $s, $s eq $s2 ?? " OK" !! " NOT OK $s2";

}</lang>

Output:
         Soundex S532 OK
         Example E251 OK
        Sownteks S532 OK
        Ekzampul E251 OK
           Euler E460 OK
           Gauss G200 OK
         Hilbert H416 OK
           Knuth K530 OK
           Lloyd L300 OK
     Lukasiewicz L222 OK
          Ellery E460 OK
           Ghosh G200 OK
       Heilbronn H416 OK
            Kant K530 OK
            Ladd L300 OK
       Lissajous L222 OK
         Wheaton W350 OK
        Ashcraft A261 OK
       Burroughs B620 OK
         Burrows B620 OK
          O'Hara O600 OK

PHP

PHP already has a built-in soundex() function: <lang php><?php echo soundex("Soundex"), "\n"; // S532 echo soundex("Example"), "\n"; // E251 echo soundex("Sownteks"), "\n"; // S532 echo soundex("Ekzampul"), "\n"; // E251 ?></lang>

PicoLisp

Simple: <lang PicoLisp>(de soundex (Str)

  (pack
     (pad -4
        (cons
           (uppc (char (char Str)))
           (head 3
              (let Last NIL
                 (extract
                    '((C)
                       (and
                          (setq C
                             (case (uppc C)
                                (`(chop "BFPV") "1")
                                (`(chop "CGJKQSXZ") "2")
                                (("D" "T") "3")
                                ("L" "4")
                                (("M" "N") "5")
                                ("R" "6") ) )
                          (<> Last C)
                          (setq Last C) ) )
                    (cdr (chop Str)) ) ) ) ) ) ) )</lang>

NARA: <lang PicoLisp>(de soundex (Str)

  (let (Str (chop Str) Last)
     (pack
        (pad
           -4
           (cons
              (uppc (car Str))
              (head
                 3
                 (filter
                    gt0
                    (cdr
                       (mapcar
                          '((C)
                             (and
                                (setq C
                                   (case (uppc C)
                                      (`(chop "AEIOUY") 0)
                                      (`(chop "BFPV") 1)
                                      (`(chop "CGJKQSXZ") 2)
                                      (("D" "T") 3)
                                      ("L" 4)
                                      (("M" "N") 5)
                                      ("R" 6) ) )
                                (<> Last C)
                                (setq Last C) ) )
                          Str ) ) ) ) ) ) ) ) )</lang>

PL/I

<lang PL/I>Soundex: procedure (pword) returns (character(4));

  declare pword character (*) varying, value character (length(pword)) varying;
  declare word character (length(pword));
  declare (prevCode, currCode) character (1);
  declare alphabet CHARACTER (26) STATIC INITIAL ('AEIOUHWYBFPVCGJKQSXZDTLMNR');
  declare replace  character (26) static initial ('00000000111122222222334556');
  declare i fixed binary;
  word = pword;
  /* Buffer to build up with character codes */
  value = ; 
  /* Make sure the word is at least two characters in length. */
  if length(word) <= 1 then return (word);
  word = uppercase(word); /* Convert to uppercase. */
  /* The current and previous character codes */
  prevCode = '0'; 
  value = substr(word, 1, 1); /* The first character is unchanged. */
  word = Translate (word, replace, alphabet);
  /* Loop through the remaining characters ... */
  do i = 2 to length(word);
     currCode = substr(word, i, 1);
     /* Check to see if the current code is the same as the last one */
     if currCode ^= prevCode & currCode ^= '0' then
        /* If the current code is a vowel, ignore it. */
        value = value || currCode;
     /* Set the new previous character code */
     prevCode = currCode; 
  end; /* of do i = ... */
  return ( left(value, 4, '0') ); /* Pad, if necessary. */
        

end Soundex;</lang>

PowerShell

Works with: PowerShell 3.0

<lang PowerShell> function Get-Soundex {

   [CmdletBinding()]
   [OutputType([PSCustomObject])]
   Param
   (
       [Parameter(Mandatory=$true,
                  ValueFromPipeline=$true,
                  ValueFromPipelineByPropertyName=$true, 
                  Position=0)]
       [string[]]
       $InputObject
   )
   Begin
   {
       $characterGroup = [PSCustomObject]@{
           1 = @('B','F','P','V')
           2 = @('C','G','J','K','Q','S','X','Z')
           3 = @('D','T')
           4 = @('L')
           5 = @('M','N')
           6 = @('R')
       }
       function ConvertTo-SoundexDigit ([char]$Character)
       {
           switch ($Character)
           {
               {$_ -in $characterGroup.1} {return 1}
               {$_ -in $characterGroup.2} {return 2}
               {$_ -in $characterGroup.3} {return 3}
               {$_ -in $characterGroup.4} {return 4}
               {$_ -in $characterGroup.5} {return 5}
               {$_ -in $characterGroup.6} {return 6}
               Default                    {return 0}
           }
       }
   }
   Process
   {
       foreach ($String in $InputObject)
       {
           $originalString = $String
           $String = $String.ToUpper()
           $isHorWcharacter = $false
           $soundex = New-Object -TypeName System.Text.StringBuilder
           $soundex.Append($String[0]) | Out-Null
           for ($i = 1; $i -lt $String.Length; $i++)
           { 
               $currentCharacterDigit = ConvertTo-SoundexDigit $String[$i]
               if ($currentCharacterDigit -ne 0)
               {
                   if ($i -eq (ConvertTo-SoundexDigit $String[$i-1]))
                   {
                       continue
                   }
                   if (($i -gt 2) -and ($isHorWcharacter) -and ($currentCharacterDigit -eq (ConvertTo-SoundexDigit $String[$i-2])))
                   {
                       continue
                   }
                   $soundex.Append($currentCharacterDigit) | Out-Null
               }
               $isHorWcharacter = $String[$i] -in @('H','W')
           }
           $soundexTail = ($soundex.ToString().Substring(1)).TrimStart((ConvertTo-SoundexDigit $String[0]).ToString())
           [PSCustomObject]@{
               String  = $originalString
               Soundex = ($soundex[0] + $soundexTail).PadRight(4,"0").Substring(0,4)
           }
       }
   }

} </lang> <lang PowerShell> "Ashcraft", "Ashcroft", "Gauss", "Ghosh", "Hilbert", "Heilbronn", "Lee", "Lloyd", "Moses", "Pfister", "Robert", "Rupert", "Rubin", "Tymczak", "Soundex", "Example" | Get-Soundex </lang>

Output:
String    Soundex
------    -------
Ashcraft  A261   
Ashcroft  A261   
Gauss     G000   
Ghosh     G000   
Hilbert   H416   
Heilbronn H465   
Lee       L000   
Lloyd     L300   
Moses     M220   
Pfister   P236   
Robert    R163   
Rupert    R163   
Rubin     R150   
Tymczak   T522   
Soundex   S532   
Example   E251   

Prolog

Note: Rather than produce a terse and incomprehensible example, this demonstrates how simply a set of logical rules can be translated into Prolog. <lang Prolog>%____________________________________________________________________ % Implements the American soundex algorithm % as described at https://en.wikipedia.org/wiki/Soundex % In SWI Prolog, a 'string' is specified in 'single quotes', % while a "list of codes" may be specified in "double quotes". % So, "abc" is equivalent to [97, 98, 99], while % 'abc' = abc (an atom), and 'Abc' is also an atom. There are % conversion methods that can produce lists of characters: %  ?- atom_chars('Abc', X). % X = ['A', b, c]. % or lists of codes (mapping to unicode code points): %  ?- atom_codes('Abc', X). % X = [65, 98, 99]. % and the conversion predicates are bidirectional. %  ?- atom_codes(A, [65, 98, 99]). % A = 'Abc'. % A single character code may be specified as 0'C, where C is the % character you want to convert to a code. %~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

% Relates groups of consonants to representative digits creplace(Ch, 0'1) :- member(Ch, "bfpv"). creplace(Ch, 0'2) :- member(Ch, "cgjkqsxz"). creplace(Ch, 0'3) :- member(Ch, "dt"). creplace(0'l, 0'4). creplace(Ch, 0'5) :- member(Ch, "mn"). creplace(0'r, 0'6).

% strips elements contained in <Set> from a string strip(Set, [H|T], Tr) :- memberchk(H, Set), !, strip(Set, T, Tr). strip(Set, [H|T], [H|Tr]) :- !, strip(Set, T, Tr). strip(_, [], []).

% Replace consonants with appropriate digits consonants([H|T], [Ch|Tr]) :- creplace(H, Ch), !, consonants(T, Tr). consonants([H|T], [H|Tr]) :- !, consonants(T, Tr). consonants([], []).

% Replace adjacent digits with single digit adjacent([Ch, Ch|T], [Ch|Tr]) :- between(0'0, 0'9, Ch), !, adjacent(T, Tr). adjacent([H|T], [H|Tr]) :- !, adjacent(T, Tr). adjacent([], []).

% Replace first character with original one if its a digit chk_digit([H,D|T], [H|T]) :- between(0'0, 0'9, D), !. chk_digit([_,H|T], [H|T]).

% Faithul representation of soundex rules: % 1: Save 1st letter, strip "hw" % 2: Replace consonants with appropriate digits % 3: Replace adjacent digits with single occurrence % 4: Remove vowels except 1st letter % 5: If 1st symbol is a digit, replace it with saved 1st letter % 6: Ensure trailing zeroes do_soundex([H|T], Res) :- strip("hw", T, Ts), consonants([H|Ts], Tc), adjacent(Tc, [C|Ta]), strip("aeiouy", Ta, Tv), chk_digit([H,C|Tv], Td), append(Td, "0000", Tr), atom_codes(Tf, Tr), sub_string(Tf, 0, 4, _, Res).

% Prepare string, convert to lower case and do the soundex alogorithm soundex(Text, Res) :- downcase_atom(Text, Lower), atom_codes(Lower, T), do_soundex(T, Res).

% Perform tests to check that the right values are produced test(S,V) :- not(soundex(S,V)), writef('%w failed\n', [S]). test :- test('Robert', 'r163'), !, fail. test :- test('Rupert', 'r163'), !, fail. test :- test('Rubin', 'r150'), !, fail. test :- test('Ashcroft', 'a261'), !, fail. test :- test('Ashcraft', 'a261'), !, fail. test :- test('Tymczak', 't522'), !, fail. test :- test('Pfister', 'p236'), !, fail. test.  % Succeeds only if all the tests succeed</lang>

PureBasic

<lang PureBasic>Procedure.s getCode(c.s)

   Protected  getCode.s = ""
    
   If FindString("BFPV", c ,1)     : getCode = "1" : EndIf
   If FindString("CGJKQSXZ", c ,1) : getCode = "2" : EndIf 
   If FindString("DT", c ,1)       : getCode = "3" : EndIf
   If "L" = c                      : getCode = "4" : EndIf
   If FindString("MN", c ,1)       : getCode = "5" : EndIf
   If "R" = c                      : getCode = "6" : EndIf 
   If FindString("HW", c ,1)       : getCode = "." : EndIf
   ProcedureReturn getCode

EndProcedure

Procedure.s soundex(word.s)

   Protected.s previous.s = "" , code.s , current , soundex
   Protected.i i
   
   word = UCase(word)
   code = Mid(word,1,1)
   previous = ""
   For i = 2 To (Len(word) + 1)
       current = getCode(Mid(word, i, 1))
       If current = "." : Continue : EndIf
       If Len(current) > 0 And current <> previous
           code + current
       EndIf
       previous = current
       If Len(code) = 4
         Break
       EndIf  
   Next
   If Len(code) < 4 
       code = LSet(code, 4,"0")
   EndIf
   ProcedureReturn code

EndProcedure

OpenConsole()

PrintN (soundex("Lukasiewicz")) PrintN("Press any key to exit"): Repeat: Until Inkey() <> ""</lang>

Python

<lang python>from itertools import groupby

def soundex(word):

  codes = ("bfpv","cgjkqsxz", "dt", "l", "mn", "r")
  soundDict = dict((ch, str(ix+1)) for ix,cod in enumerate(codes) for ch in cod)
  cmap2 = lambda kar: soundDict.get(kar, '9')
  sdx =  .join(cmap2(kar) for kar in word.lower())
  sdx2 = word[0].upper() + .join(k for k,g in list(groupby(sdx))[1:] if k!='9')
  sdx3 = sdx2[0:4].ljust(4,'0')
  return sdx3

</lang>

Output:

<lang Python>>>>print soundex("soundex") S532 >>>print soundex("example") E251 >>>print soundex("ciondecks") C532 >>>print soundex("ekzampul") E251</lang>

Racket

The Scheme solution runs as is in Racket.

REXX

Some assumptions made:

  •   rules are from the algorithm for the American Soundex.
  •   rules were taken from the Wikipedia article: http://en.wikipedia.org/wiki/Soundex
  •   multiple words   (like Van de Graaff)   are treated as one word.
  •   anything that's not a letter of the Latin alphabet is ignored.
  •   words starting with a non-letter are processed.
  •   letters of the ASCII-extended character set are ignored.
  •   ASCII-extended characters (ÇüéâäàåçêëèïîìÄÅÉæÆôöòûùÿÖÜíóúñÑ) could be added to the program easily.

<lang rexx>/*REXX program demonstrates Soundex codes from some words or from the command line.*/ _=; @.= /*set a couple of vars to "null".*/ parse arg @.0 . /*allow input from command line. */

                          @.1   = "12346"         ;        #.1   = '0000'
                          @.4   = "4-H"           ;        #.4   = 'H000'
                          @.11  = "Ashcraft"      ;        #.11  = 'A261'
                          @.12  = "Ashcroft"      ;        #.12  = 'A261'
                          @.18  = "auerbach"      ;        #.18  = 'A612'
                          @.20  = "Baragwanath"   ;        #.20  = 'B625'
                          @.22  = "bar"           ;        #.22  = 'B600'
                          @.23  = "barre"         ;        #.23  = 'B600'
                          @.20  = "Baragwanath"   ;        #.20  = 'B625'
                          @.28  = "Burroughs"     ;        #.28  = 'B620'
                          @.29  = "Burrows"       ;        #.29  = 'B620'
                          @.30  = "C.I.A."        ;        #.30  = 'C000'
                          @.37  = "coöp"          ;        #.37  = 'C100'
                          @.43  = "D-day"         ;        #.43  = 'D000'
                          @.44  = "d jay"         ;        #.44  = 'D200'
                          @.45  = "de la Rosa"    ;        #.45  = 'D462'
                          @.46  = "Donnell"       ;        #.46  = 'D540'
                          @.47  = "Dracula"       ;        #.47  = 'D624'
                          @.48  = "Drakula"       ;        #.48  = 'D624'
                          @.49  = "Du Pont"       ;        #.49  = 'D153'
                          @.50  = "Ekzampul"      ;        #.50  = 'E251'
                          @.51  = "example"       ;        #.51  = 'E251'
                          @.55  = "Ellery"        ;        #.55  = 'E460'
                          @.59  = "Euler"         ;        #.59  = 'E460'
                          @.60  = "F.B.I."        ;        #.60  = 'F000'
                          @.70  = "Gauss"         ;        #.70  = 'G200'
                          @.71  = "Ghosh"         ;        #.71  = 'G200'
                          @.72  = "Gutierrez"     ;        #.72  = 'G362'
                          @.80  = "he"            ;        #.80  = 'H000'
                          @.81  = "Heilbronn"     ;        #.81  = 'H416'
                          @.84  = "Hilbert"       ;        #.84  = 'H416'
                          @.100 = "Jackson"       ;        #.100 = 'J250'
                          @.104 = "Johnny"        ;        #.104 = 'J500'
                          @.105 = "Jonny"         ;        #.105 = 'J500'
                          @.110 = "Kant"          ;        #.110 = 'K530'
                          @.116 = "Knuth"         ;        #.116 = 'K530'
                          @.120 = "Ladd"          ;        #.120 = 'L300'
                          @.124 = "Llyod"         ;        #.124 = 'L300'
                          @.125 = "Lee"           ;        #.125 = 'L000'
                          @.126 = "Lissajous"     ;        #.126 = 'L222'
                          @.128 = "Lukasiewicz"   ;        #.128 = 'L222'
                          @.130 = "naïve"         ;        #.130 = 'N100'
                          @.141 = "Miller"        ;        #.141 = 'M460'
                          @.143 = "Moses"         ;        #.143 = 'M220'
                          @.146 = "Moskowitz"     ;        #.146 = 'M232'
                          @.147 = "Moskovitz"     ;        #.147 = 'M213'
                          @.150 = "O'Conner"      ;        #.150 = 'O256'
                          @.151 = "O'Connor"      ;        #.151 = 'O256'
                          @.152 = "O'Hara"        ;        #.152 = 'O600'
                          @.153 = "O'Mally"       ;        #.153 = 'O540'
                          @.161 = "Peters"        ;        #.161 = 'P362'
                          @.162 = "Peterson"      ;        #.162 = 'P362'
                          @.165 = "Pfister"       ;        #.165 = 'P236'
                          @.180 = "R2-D2"         ;        #.180 = 'R300'
                          @.182 = "rÄ≈sumÅ∙"      ;        #.182 = 'R250'
                          @.184 = "Robert"        ;        #.184 = 'R163'
                          @.185 = "Rupert"        ;        #.185 = 'R163'
                          @.187 = "Rubin"         ;        #.187 = 'R150'
                          @.191 = "Soundex"       ;        #.191 = 'S532'
                          @.192 = "sownteks"      ;        #.192 = 'S532'
                          @.199 = "Swhgler"       ;        #.199 = 'S460'
                          @.202 = "'til"          ;        #.202 = 'T400'
                          @.208 = "Tymczak"       ;        #.208 = 'T522'
                          @.216 = "Uhrbach"       ;        #.216 = 'U612'
                          @.221 = "Van de Graaff" ;        #.221 = 'V532'
                          @.222 = "VanDeusen"     ;        #.222 = 'V532'
                          @.230 = "Washington"    ;        #.230 = 'W252'
                          @.233 = "Wheaton"       ;        #.233 = 'W350'
                          @.234 = "Williams"      ;        #.234 = 'W452'
                          @.236 = "Woolcock"      ;        #.236 = 'W422'
     do k=0  for 300;     if @.k==  then iterate;        $=soundex(@.k)
     say word('nope [ok]', 1 +($==#.k | k==0))   _   $   "is the Soundex for"   @.k
     if k==0  then leave
     end   /*k*/

exit /*stick a fork in it, we're done.*/ /*──────────────────────────────────────────────────────────────────────────────────────*/ soundex: procedure; arg x /*ARG uppercases the var X. */

        old_alphabet= 'AEIOUYHWBFPVCGJKQSXZDTLMNR'
        new_alphabet= '@@@@@@**111122222222334556'
        word=                                            /* [+]  exclude  non-letters. */
               do i=1  for length(x);  _=substr(x, i, 1) /*obtain a character from word*/
               if datatype(_,'M')  then word=word || _   /*Upper/lower letter?  Then OK*/
               end   /*i*/
        value=strip(left(word, 1))                       /*1st character is left alone.*/
        word=translate(word, new_alphabet, old_alphabet) /*define the current  word.   */
        prev=translate(value,new_alphabet, old_alphabet) /*   "    "  previous   "     */
          do j=2  to length(word)                        /*process remainder of word.  */
          ?=substr(word, j, 1)
          if ?\==prev & datatype(?,'W')  then do;  value=value || ?;  prev=?;  end
                                         else if ?=='@'  then prev=?
          end   /*j*/
        return left(value,4,0)                           /*padded value with zeroes.   */</lang>

output   when using the default (internal) inputs:

[ok]  0000 is the Soundex for 12346
[ok]  H000 is the Soundex for 4-H
[ok]  A261 is the Soundex for Ashcraft
[ok]  A261 is the Soundex for Ashcroft
[ok]  A612 is the Soundex for auerbach
[ok]  B625 is the Soundex for Baragwanath
[ok]  B600 is the Soundex for bar
[ok]  B600 is the Soundex for barre
[ok]  B620 is the Soundex for Burroughs
[ok]  B620 is the Soundex for Burrows
[ok]  C000 is the Soundex for C.I.A.
[ok]  C100 is the Soundex for coöp
[ok]  D000 is the Soundex for d-day
[ok]  D200 is the Soundex for d jay
[ok]  D462 is the Soundex for de la Rosa
[ok]  D540 is the Soundex for Donnell
[ok]  D624 is the Soundex for Dracula
[ok]  D624 is the Soundex for Drakula
[ok]  D153 is the Soundex for Du Pont
[ok]  E251 is the Soundex for Ekzampul
[ok]  E251 is the Soundex for example
[ok]  E460 is the Soundex for Ellery
[ok]  E460 is the Soundex for Euler
[ok]  F000 is the Soundex for F.B.I.
[ok]  G200 is the Soundex for Gauss
[ok]  G200 is the Soundex for Ghosh
[ok]  G362 is the Soundex for Gutierrez
[ok]  H000 is the Soundex for he
[ok]  H416 is the Soundex for Heilbronn
[ok]  H416 is the Soundex for Hilbert
[ok]  J250 is the Soundex for Jackson
[ok]  J500 is the Soundex for Johnny
[ok]  J500 is the Soundex for Jonny
[ok]  K530 is the Soundex for Kant
[ok]  K530 is the Soundex for Knuth
[ok]  L300 is the Soundex for Ladd
[ok]  L300 is the Soundex for Llyod
[ok]  L000 is the Soundex for Lee
[ok]  L222 is the Soundex for Lissajous
[ok]  L222 is the Soundex for Lukasiewicz
[ok]  N100 is the Soundex for naïve
[ok]  M460 is the Soundex for Miller
[ok]  M220 is the Soundex for Moses
[ok]  M232 is the Soundex for Moskowitz
[ok]  M213 is the Soundex for Moskovitz
[ok]  O256 is the Soundex for O'Conner
[ok]  O256 is the Soundex for O'Connor
[ok]  O600 is the Soundex for O'Hara
[ok]  O540 is the Soundex for O'Mally
[ok]  P362 is the Soundex for Peters
[ok]  P362 is the Soundex for Peterson
[ok]  P236 is the Soundex for Pfister
[ok]  R300 is the Soundex for R2-D2
[ok]  R250 is the Soundex for rÄ≈sumÅ∙
[ok]  R163 is the Soundex for Robert
[ok]  R163 is the Soundex for Rupert
[ok]  R150 is the Soundex for Rubin
[ok]  S532 is the Soundex for Soundex
[ok]  S532 is the Soundex for sownteks
[ok]  S460 is the Soundex for Swhgler
[ok]  T400 is the Soundex for 'til
[ok]  T522 is the Soundex for Tymczak
[ok]  U612 is the Soundex for Uhrbach
[ok]  V532 is the Soundex for Van de Graaff
[ok]  V532 is the Soundex for VanDeusen
[ok]  W252 is the Soundex for Washington
[ok]  W350 is the Soundex for Wheaton
[ok]  W452 is the Soundex for Williams
[ok]  W422 is the Soundex for Woolcock

Ruby

Courtesy http://snippets.dzone.com/posts/show/4530 <lang ruby>class String

 SoundexChars = 'BFPVCGJKQSXZDTLMNR'
 SoundexNums  = '111122222222334556'
 SoundexCharsEx = '^' + SoundexChars
 SoundexCharsDel = '^A-Z'
 # desc: http://en.wikipedia.org/wiki/Soundex
 def soundex(census = true)
   str = self.upcase.delete(SoundexCharsDel)
   str[0,1] + str[1..-1].delete(SoundexCharsEx).
                         tr_s(SoundexChars, SoundexNums)\
                         [0 .. (census ? 2 : -1)].
                         ljust(3, '0') rescue 
 end
 def sounds_like(other)
   self.soundex == other.soundex
 end

end

%w(Soundex Sownteks Example Ekzampul foo bar).each_slice(2) do |word1, word2|

 [word1, word2].each {|word| puts '%-8s -> %s' % [word, word.soundex]}
 print "'#{word1}' "
 print word1.sounds_like(word2) ? "sounds" : "does not sound"
 print " like '#{word2}'\n"

end</lang>

Soundex  -> S532
Sownteks -> S532
'Soundex' sounds like 'Sownteks'
Example  -> E251
Ekzampul -> E251
'Example' sounds like 'Ekzampul'
foo      -> F000
bar      -> B600
'foo' does not sound like 'bar'

Run BASIC

Courtesy http://dkokenge.com/rbp <lang runbasic>global val$ val$(1) = "BPFV" val$(2) = "CSGJKQXZ" val$(3) = "DT" val$(4) = "L" val$(5) = "MN" val$(6) = "R"

' --------------------------------- ' show soundex on these words ' --------------------------------- w$(1) = "Robert" 'R163 w$(2) = "Rupert" 'R163 w$(3) = "Rubin" 'R150 w$(4) = "moses" 'M220 w$(5) = "O'Mally" 'O540 w$(6) = "d jay" 'D200

for i = 1 to 6

 print w$(i);" soundex:";soundex$(w$(i))

next i wait

' --------------------------------- ' Return soundex of word ' --------------------------------- function soundex$(a$) a$ = upper$(a$) for i = 2 to len(a$)

 theLtr$ = mid$(a$,i,1)
 s$      = "0"
 if instr("AEIOUYHW |",theLtr$) <> 0 then s$ = ""
 if theLtr$ <> preLtr$ then
   for j = 1 to 6
    if instr(val$(j),theLtr$) <> 0 then s$ = str$(j)
   next j
 end if
 sdx$    = sdx$ + s$
 preLtr$ = theLtr$

next i soundex$ = left$(a$,1) + left$(sdx$;"000",3) end function</lang>

Robert soundex:R163
Rupert soundex:R163
Rubin soundex:R150
moses soundex:M220
O'Mally soundex:O054
d jay soundex:D200

Scala

<lang scala>def soundex(s:String)={

  var code=s.head.toUpper.toString
  var previous=getCode(code.head)
  for(ch <- s.drop(1); current=getCode(ch.toUpper)){
     if (!current.isEmpty && current!=previous)
        code+=current
     previous=current
  }
  code+="0000"
  code.slice(0,4)

}

def getCode(c:Char)={

  val code=Map("1"->List('B','F','P','V'),
     "2"->List('C','G','J','K','Q','S','X','Z'),
     "3"->List('D', 'T'),
     "4"->List('L'),
     "5"->List('M', 'N'),
     "6"->List('R'))
  code.find(_._2.exists(_==c)) match {
     case Some((k,_)) => k
     case _ => ""
  }

}</lang>

<lang scala>def main(args: Array[String]): Unit = {

  val tests=Map(
     "Soundex"     -> "S532",
     "Euler"	    -> "E460",
     "Gauss"	    -> "G200",
     "Hilbert"	    -> "H416",
     "Knuth"	    -> "K530",
     "Lloyd"	    -> "L300",
     "Lukasiewicz" -> "L222",
     "Ellery"	    -> "E460",
     "Ghosh"	    -> "G200",
     "Heilbronn"   -> "H416",
     "Kant"	    -> "K530",
     "Ladd"	    -> "L300",
     "Lissajous"   -> "L222",
     "Wheaton"	    -> "W350",
     "Ashcraft"    -> "A226",
     "Burroughs"   -> "B622",
     "Burrows"	    -> "B620",
     "O'Hara"	    -> "O600")
  tests.foreach{(v)=>
     val code=soundex(v._1)
     val status=if (code==v._2) "OK" else "ERROR"
     printf("Name: %-20s  Code: %s   Found: %s  - %s\n", v._1, v._2, code, status)
  }

}</lang>

Scheme

This implements American Soundex as described at [3].

Works with: any R6RS Scheme

<lang scheme>;; The American Soundex System

The soundex code consist of the first letter of the name followed
by three digits. These three digits are determined by dropping the
letters a, e, i, o, u, h, w and y and adding three digits from the
remaining letters of the name according to the table below. There
are only two additional rules. (1) If two or more consecutive
letters have the same code, they are coded as one letter. (2) If
there are an insufficient numbers of letters to make the three
digits, the remaining digits are set to zero.
Soundex Table
1 b,f,p,v
2 c,g,j,k,q,s,x,z
3 d, t
4 l
5 m, n
6 r
Examples
Miller M460
Peterson P362
Peters P362
Auerbach A612
Uhrbach U612
Moskowitz M232
Moskovitz M213

(define (char->soundex c)

 (case (char-upcase c)
   ((#\B #\F #\P #\V) #\1)
   ((#\C #\G #\J #\K #\Q #\S #\X #\Z) #\2)
   ((#\D #\T) #\3)
   ((#\L) #\4)
   ((#\M #\N) #\5)
   ((#\R) #\6)
   (else #\nul)))

(define (collapse-dups lst)

 (if (= (length lst) 1) lst
     (if (equal? (car lst) (cadr lst))

(collapse-dups (cdr lst)) (cons (car lst) (collapse-dups (cdr lst))))))

(define (remove-nul lst)

 (filter (lambda (c)

(not (equal? c #\nul))) lst))

(define (force-len n lst)

 (cond ((= n 0) '())

((null? lst) (force-len n (list #\0))) (else (cons (car lst) (force-len (- n 1) (cdr lst))))))

(define (soundex s)

 (let ((slst (string->list s)))
   (force-len 4 (cons (char-upcase (car slst))

(remove-nul (collapse-dups (map char->soundex (cdr slst))))))))

(soundex "miller") (soundex "Peterson") (soundex "PETERS") (soundex "auerbach") (soundex "Uhrbach") (soundex "Moskowitz") (soundex "Moskovitz")</lang>

Output:
> "M460"
> "P362"
> "P362"
> "A612"
> "U612"
> "M232"
> "M213"

Sidef

<lang ruby>func soundex(word, length=3) {

   # Uppercase the argument passed in to normalize it
   # and drop any non-alphabetic characters
   word.uc!.tr!('A-Z', , 'cd')
   # Return if word does not contain 'A-Z'
   return(nil) if (word.is_empty)
   var firstLetter = word.char(0)
   # Replace letters with corresponding number values
   word.tr!('BFPV',     '1', 's')
   word.tr!('CGJKQSXZ', '2', 's')
   word.tr!('DT',       '3', 's')
   word.tr!('L',        '4', 's')
   word.tr!('MN',       '5', 's')
   word.tr!('R',        '6', 's')
   # Discard the first letter
   word.ft!(1)
   # Remove A, E, H, I, O, U, W, and Y
   word.tr!('AEHIOUWY', , 'd')
   # Return the soundex code
   firstLetter + (word.chars + length.of('0') -> first(length).join)

}

func testSoundex {

   # Key-value pairs of names and corresponding Soundex codes
   var sndx = Hash(
               "Euler"                => "E4600",
               "Gauss"                => "G2000",
               "Hilbert"              => "H4163",
               "Knuth"                => "K5300",
               "Lloyd"                => "L3000",
               "Lukasieicz"           => "L2220",
               'fulkerson'            => 'F4262',
               'faulkersuhn'          => 'F4262',
               'fpfffffauhlkkersssin' => 'F4262',
               'Aaeh'                 => 'A0000',
              )
   sndx.keys.sort.each { |name|
       var findSdx = soundex(name, 4)
       say "The soundex for #{name} should be #{sndx{name}} and is #{findSdx}"
       if (findSdx != sndx{name}) {
           say "\tHowever, that is incorrect!\n"
       }
   }

}

testSoundex()</lang>

SNOBOL4

Works with: Macro Spitbol
Works with: Snobol4+
Works with: CSnobol

US National Archives (NARA) Soundex. Includes the "HW" rule omitted by Knuth and many other implementations.

<lang SNOBOL4>* # Soundex coding

  • # ABCDEFGHIJKLMNOPQRSTUVWXYZ
  • # 01230127022455012623017202
       define('soundex(str)init,ch') :(soundex_end)

soundex sdxmap = '01230127022455012623017202'

       str = replace(str,&lcase,&ucase)

sdx1 str notany(&ucase) = :s(sdx1)

       init = substr(str,1,1)
       str = replace(str,&ucase,sdxmap)

sdx2 str len(1) $ ch span(*ch) = ch :s(sdx2)

  • # Omit next line for Knuth's simple Soundex

sdx3 str len(1) $ ch ('7' *ch) = ch :s(sdx3)

       str len(1) = init

sdx4 str any('07') = :s(sdx4)

       str = substr(str,1,4)
       str = lt(size(str),4) str dupl('0',4 - size(str))
       soundex = str :(return)

soundex_end

  • # Test and display
       test = " Washington Lee Gutierrez Pfister Jackson Tymczak"

+ " Ashcroft Swhgler O'Connor Rhys-Davies" loop test span(' ') break(' ') . name = :f(end)

       output = soundex(name) ' ' name :(loop)

end</lang>

Output:
W252 Washington
L000 Lee
G362 Gutierrez
P236 Pfister
J250 Jackson
T522 Tymczak
A261 Ashcroft
S460 Swhgler
O256 O'Connor

Smalltalk

Works with: Smalltalk/X

using a builtin utility: <lang smalltalk>PhoneticStringUtilities soundexCodeOf: 'Soundex' "-> S532"</lang>

Standard ML

This implementation uses datatypes to encode the different rules for handling duplicate digits when different characters appear in the input: <lang sml>(* There are 3 kinds of letters:

*   h and w are ignored completely (letters separated by h or w are considered
*     adjacent, or merged together)
*   vowels are ignored, but letters separated by a vowel are split apart.
*   All consonants but h and w map to a digit *)

datatype code =

        Merge
      | Split
      | Digit of char

(* Encodes which characters map to which codes *) val codeTable =

[([#"H", #"W"], Merge),
 ([#"A",#"E",#"I", #"O",#"U",#"Y"], Split),
 ([#"B",#"F",#"P",#"V"], Digit #"1"),
 ([#"C",#"G",#"J",#"K",#"Q",#"S",#"X",#"Z"], Digit #"2"),
 ([#"D",#"T"], Digit #"3"),
 ([#"L"], Digit #"4"),
 ([#"M",#"N"], Digit #"5"),
 ([#"R"], Digit #"6")]

(* Find the code that matches a given character *) fun codeOf (c : char) =

   #2 (valOf (List.find (fn (L,_) => isSome(List.find (fn c' => c = c') L)) codeTable))

(* Remove all the non-digit codes, combining like digits when appropriate. *) fun collapse (c :: Merge :: cs) = collapse (c :: cs)

 | collapse (Digit d :: Split :: cs) = Digit d :: collapse cs
 | collapse (Digit d :: (cs' as Digit d' :: cs)) =
   if d = d' then collapse (Digit d :: cs)
   else Digit d :: collapse cs'
 | collapse [Digit d] = [Digit d]
 | collapse (c::cs) = collapse cs
 | collapse _ = []

(* dropWhile f L removes the initial elements of L that satisfy f and returns

* the rest *)

fun dropWhile f [] = []

 | dropWhile f (x::xs) =
   if f x then dropWhile f xs
   else x::xs

fun soundex (s : string) =

   let
     (* Normalize the string to uppercase letters only *)
     val c::cs = map (Char.toUpper) (filter Char.isAlpha(String.explode s))
     fun first3 L = map (fn Digit c => c) (List.take(L,3))
     val padding = [Digit #"0", Digit #"0", Digit #"0"]
     (* Remove any initial section that has the same code as the first character.
      * This comes up in the "Pfister" test case. *)
     val codes = dropWhile (fn Merge => true | Digit d => Digit d = codeOf c | Split => false)
                           (map codeOf (c::cs))
   in
     String.implode(c::first3(collapse codes@padding))
   end

(* Some test cases from Wikipedia *) fun test input output =

   if soundex input = output then ()
   else raise Fail ("Soundex of " ^ input ^ " should be " ^ output ^ ", not " ^ soundex input)

val () = test "Rupert" "R163" val () = test "Robert" "R163" val () = test "Rubin" "R150" val () = test "Tymczak" "T522" val () = test "Pfister" "P236"</lang>

Tcl

Library: Tcllib (Package: soundex)
contains an implementation of Knuth's soundex algorithm.

<lang tcl>package require soundex

foreach string {"Soundex" "Example" "Sownteks" "Ekzampul"} {

   set soundexCode [soundex::knuth $string]
   puts "\"$string\" has code $soundexCode"

}</lang>

Output:
"Soundex" has code S532
"Example" has code E251
"Sownteks" has code S532
"Ekzampul" has code E251

TSE SAL

<lang TSE SAL>

// library: string: get: soundex <description></description> <version>1.0.0.0.35</version> <version control></version control> (filenamemacro=getstgso.s) [kn, ri, sa, 15-10-2011 18:23:04] STRING PROC FNStringGetSoundexS( STRING inS )

// Except the first character, you replace each character in the string with its corresponding mapping number
// Idea is that you give characters with the same sound the same mapping number (e.g. 'c' is replaced by '2'. And 'k' which might sound the same as a 'c' is also replaced by the same '2'
STRING map1S[255] = "AEHIOUWYBFPVCGJKQSXZDTLMNR"
STRING map2S[255] = "00000000111122222222334556"
STRING s[255] = Upper( inS )
STRING soundexS[255] = ""
STRING characterCurrentS[255] = ""
STRING characterPreviousS[255] = "?"
STRING characterMapS[255] = ""
INTEGER mapPositionI = 0
INTEGER minI = 1
INTEGER I = minI
INTEGER maxI = Length( s )
I = minI
characterCurrentS = SubStr( s, I, 1 )
mapPositionI = Pos( characterCurrentS, map1S )
WHILE ( ( I <= maxI ) AND ( Length( soundexS ) < 4 ) AND ( NOT ( mapPositionI == 0 ) ) )
 // Skip double letters, like CC, KK, PP, ...
 IF ( NOT ( mapPositionI == 0 ) ) AND ( NOT ( characterCurrentS == characterPreviousS ) )
  characterPreviousS = characterCurrentS
  // First character is extracted unchanged, for sorting purposes.
  IF ( I == minI )
   soundexS = Format( soundexS, characterCurrentS )
  ELSE
   mapPositionI = Pos( characterCurrentS, map1S )
   IF ( NOT ( mapPositionI == 0 ) )
    characterMapS = SubStr( map2S, mapPositionI, 1 )
    // skip vowels A, E, I, O, U, further also H, W and Y. In general all characters which have a mapping value of "0"
    IF ( NOT ( characterMapS == "0" ) )
     soundexS = Format( soundexS, characterMapS )
    ENDIF
   ENDIF
  ENDIF
 ENDIF
 I = I + 1
 characterCurrentS = SubStr( s, I, 1 )
ENDWHILE
IF ( NOT ( soundexS == "" ) )
 WHILE ( Length( soundexS ) < 4 )
  soundexS = Format( soundexS, "0" )
 ENDWHILE
ENDIF
RETURN( soundexS )

END

PROC Main()

STRING s1[255] = "John Doe"
// Warn( Format( FNStringGetSoundexS( "Ashcraft" ) ) ) // gives e.g. "A226" // using another rule the value might be "A261" (see Wikipedia, soundex)
// Warn( Format( FNStringGetSoundexS( "Ashcroft" ) ) ) // gives e.g. "A226" // using another rule the value might be "A261" (see Wikipedia, soundex)
// Warn( Format( FNStringGetSoundexS( "Davidson, Greg" ) ) ) // gives e.g. "D132"
// Warn( Format( FNStringGetSoundexS( "Dracula" ) ) ) // gives e.g. "D624"
// Warn( Format( FNStringGetSoundexS( "Drakula" ) ) ) // gives e.g. "D624"
// Warn( Format( FNStringGetSoundexS( "Darwin" ) ) ) // gives e.g. "D650"
// Warn( Format( FNStringGetSoundexS( "Darwin, Daemon" ) ) ) // gives e.g. "D650"
// Warn( Format( FNStringGetSoundexS( "Darwin, Ian" ) ) ) // gives e.g. "D650"
// Warn( Format( FNStringGetSoundexS( "Derwin" ) ) ) // gives e.g. "D650"
// Warn( Format( FNStringGetSoundexS( "Darwent, William" ) ) ) // gives e.g. "D653"
// Warn( Format( FNStringGetSoundexS( "Ellery" ) ) ) // gives e.g. "E460"
// Warn( Format( FNStringGetSoundexS( "Euler" ) ) ) // gives e.g. "E460"
// Warn( Format( FNStringGetSoundexS( "Ghosh" ) ) ) // gives e.g. "G200"
// Warn( Format( FNStringGetSoundexS( "Gauss" ) ) ) // gives e.g. "G200"
// Warn( Format( FNStringGetSoundexS( "Heilbronn" ) ) ) // gives e.g. "H416"
// Warn( Format( FNStringGetSoundexS( "Hilbert" ) ) ) // gives e.g. "H416"
// Warn( Format( FNStringGetSoundexS( "Johnny" ) ) ) // gives e.g. "J500"
// Warn( Format( FNStringGetSoundexS( "Jonny" ) ) ) // gives e.g. "J500"
// Warn( Format( FNStringGetSoundexS( "Kant" ) ) ) // gives e.g. "K530"
// Warn( Format( FNStringGetSoundexS( "Knuth" ) ) ) // gives e.g. "K530"
// Warn( Format( FNStringGetSoundexS( "Lissajous" ) ) ) // gives e.g. "L222"
// Warn( Format( FNStringGetSoundexS( "Lukasiewicz" ) ) ) // gives e.g. "L222"
// Warn( Format( FNStringGetSoundexS( "Ladd" ) ) ) // gives e.g. "L300"
// Warn( Format( FNStringGetSoundexS( "Lloyd" ) ) ) // gives e.g. "L300"
// Warn( Format( FNStringGetSoundexS( "Rubin" ) ) ) // gives e.g. "R150"
// Warn( Format( FNStringGetSoundexS( "Robert" ) ) ) // gives e.g. "R163"
// Warn( Format( FNStringGetSoundexS( "Rupert" ) ) ) // gives e.g. "R163"
REPEAT
 IF ( NOT ( Ask( "string: get: soundex = ", s1, _EDIT_HISTORY_ ) ) AND ( Length( s1 ) > 0 ) ) RETURN() ENDIF
 Warn( Format( FNStringGetSoundexS( s1 ) ) )
UNTIL FALSE

END

</lang>


TUSCRIPT

<lang tuscript> $$ MODE DATA

$$ BUILD X_TABLE soundex = *

b:1:f:1:p:1:v:1:
c:2:g:2:j:2:k:2:1:2:s:2:x:2:z:2:
d:3:t:3:
l:4:
m:5:n:5:
r:6:

$$ names="Christiansen'Kris Jenson'soundex'Lloyd'Woolcock'Donnell'Baragwanath'Williams'Ashcroft'Euler'Ellery'Gauss'Ghosh'Hilbert'Heilbronn'Knuth'Kant'Ladd'Lukasiewicz'Lissajous'Wheaton'Burroughs'Burrows"

$$ MODE TUSCRIPT,{} LOOP/CLEAR n=names

first=EXTRACT (n,1,2),second=EXTRACT (n,2,3)
IF (first==second) THEN
 rest=EXTRACT (n,3,0)
ELSE
 rest=EXTRACT (n,2,0)
ENDIF
soundex=EXCHANGE (rest,soundex)
soundex=STRINGS  (soundex,":{\0}:a:e:i:o:u:")
soundex=REDUCE   (soundex)
soundex=STRINGS  (soundex,":{\0}:",0,0,1,0,"")
soundex=CONCAT   (soundex,"000")
soundex=EXTRACT  (soundex,0,4)
PRINT first,soundex,"=",n

ENDLOOP </lang>

Output:
C623=Christiansen
K625=Kris Jenson
s532=soundex
L300=Lloyd
W422=Woolcock
D540=Donnell
B625=Baragwanath
W452=Williams
A261=Ashcroft
E460=Euler
E460=Ellery
G200=Gauss
G200=Ghosh
H416=Hilbert
H416=Heilbronn
K530=Knuth
K530=Kant
L300=Ladd
L222=Lukasiewicz
L222=Lissajous
W350=Wheaton
B620=Burroughs
B620=Burrows

TXR

TXR Pattern Language

This implements the full Soundex described in [U.S. National Archives Website]. Doubled letters are condensed before separating the first letter, so that for instance "Lloyd" is not treated as L followed by the coding of LOYD but as L followed by the coding of OYD. Consecutive consonants which map to the same code are not condensed to a single occurrence of the code if they are separated by vowels, but separating W and H do not thus intervene. Names with common prefixes are encoded in two ways.

<lang txr>@(next :args) @### @# soundex-related filters @### @(deffilter remdbl ("AA" "A") ("BB" "B") ("CC" "C") ("DD" "D") ("EE" "E")

                  ("FF" "F") ("GG" "G") ("HH" "H") ("II" "I") ("JJ" "J")
                  ("KK" "K") ("LL" "L") ("MM" "M") ("NN" "N") ("OO" "O")
                  ("PP" "P") ("QQ" "Q") ("RR" "R") ("SS" "S") ("TT" "T")
                  ("UU" "U") ("VV" "V") ("WW" "W") ("XX" "X") ("YY" "Y")
                  ("ZZ" "Z"))

@(deffilter code ("B" "F" "P" "V" "1")

                ("C" "G" "J" "K" "Q" "S" "X" "Z" "2")
                ("D" "T" "3") ("L" "4") ("M" "N" "5")
                ("R" "6") ("A" "E" "I" "O" "U" "Y" "0") ("H" "W" ""))

@(deffilter squeeze ("11" "111" "1111" "11111" "1")

                   ("22" "222" "2222" "22222" "2")
                   ("33" "333" "3333" "33333" "3")
                   ("44" "444" "4444" "44444" "4")
                   ("55" "555" "5555" "55555" "5")
                   ("66" "666" "6666" "66666" "6"))

@(bind prefix ("VAN" "CON" "DE" "DI" "LA" "LE")) @(deffilter remzero ("0" "")) @### @# soundex function @### @(define soundex (in out)) @ (local nodouble letters remainder first rest coded) @ (next :string in) @ (coll)@{letters /[A-Za-z]+/}@(end) @ (cat letters "") @ (output :into nodouble :filter (:upcase remdbl)) @letters @ (end) @ (next :list nodouble) @ (maybe) @prefix@remainder @ (output :into nodouble) @nodouble @remainder @ (end) @ (end) @ (next :list nodouble) @ (collect) @{first 1}@rest @ (output :filter (code squeeze remzero) :into coded) @{rest}000 @ (end) @ (next :list coded) @{digits 3}@(skip) @ (end) @ (output :into out) @ (rep):@first@digits@(first)@first@digits@(end) @ (end) @ (cat out) @(end) @### @# process arguments and list soundex codes @### @(collect :vars ()) @input @ (output :filter (:fun soundex)) @input @ (end) @(end) @### @# compare first and second argument under soundex @### @(bind (first_arg second_arg . rest_args) input) @(cases) @ (bind first_arg second_arg :filter (:fun soundex)) @ (output) "@first_arg" and "@second_arg" match under soundex @ (end) @(end)</lang>

Run:

$ txr soundex.txr example soundex Lloyd lee guttierez o\'hara vandeusen dimeola
E251
E251
S532
L300
L000
G362
O600
V532:D250
D540:M400
"example" and "egsampul" match under soundex

With TXR Lisp

This solution is similar to some of the solutions in other languages. Its treatment of the algorithm is not as complete as the above solution.

<lang txr>@(do (defun get-code (c)

      (caseq c
        ((#\B #\F #\P #\V) #\1)
        ((#\C #\G #\J #\K #\Q #\S #\X #\Z) #\2)
        ((#\D #\T) #\3)
        (#\L #\4)
        ((#\M #\N) #\5)
        (#\R #\6)))
    (defun soundex (s)
      (if (zerop (length s))
        ""
        (let* ((su (upcase-str s))
               (o [su 0]))
          (for ((i 1) (l (length su)) cp cg)
               ((< i l) [`@{o}000` 0 4])
               ((inc i) (set cp cg))
            (set cg (get-code [su i]))
            (if (and cg (not (eql cg cp)))
              (set o `@o@cg`)))))))

@(next :args) @(repeat) @arg @ (output) @arg -> @(soundex arg) @ (end) @(end)</lang>

Run:

$ ./txr soundex-lisp.txr  soundex sowndex
soundex -> S532
sowndex -> S532

UNIX Shell

Works with: Bourne Again SHell version 4

The following functions require this associative array to be declared:

<lang bash>declare -A value=(

   [B]=1 [F]=1 [P]=1 [V]=1
   [C]=2 [G]=2 [J]=2 [K]=2 [Q]=2 [S]=2 [X]=2 [Z]=2
   [D]=3 [T]=3
   [L]=4
   [M]=5 [N]=5
   [R]=6

)</lang>

The first algorithm described at https://en.wikipedia.org/wiki/Soundex#American_Soundex can be implemented like this:

<lang bash>soundex() {

   local -u word=${1//[^[:alpha:]]/.}
   local letter=${word:0:1}
   local soundex=$letter 
   local previous=$letter
   word=${word:1}
   word=${word//[AEIOUY]/.}
   word=${word//[WH]/=}
   while [[ ${#soundex} -lt 4 && -n $word ]]; do
       letter=${word:0:1}
       if $letter == "." ; then
           previous=""
       elif $letter == "=" ; then
           if [[ $previous == [A-Z] && ${word:1:1} == [A-Z] ]] &&
              [[ ${value[$previous]} -eq ${value[${word:1:1}]} ]]
           then
               word=${word:1}
           fi
       elif -z $previous  || 
            [[ $letter != $previous && ${value[$letter]} -ne ${value[$previous]} ]] 
       then
           previous=$letter
           soundex+=${value[$letter]}
       fi
       word=${word:1}
   done
   # right pad with zeros
   soundex+="000"
   echo "${soundex:0:4}"

}</lang>

The "simplified" algorithm can be implemented like this:

<lang bash>soundex2() {

   local -u word=${1//[^[:alpha:]]/}
   # 1. Save the first letter. Remove all occurrences of 'h' and 'w' except first letter.
   local first=${word:0:1}
   word=${word:1}
   word=$first${word//[HW]/}
   # 2. Replace all consonants (include the first letter) with digits as in [2.] above.
   local consonants=$(IFS=; echo "${!value[*]}")
   local tmp letter
   local -i i
   for ((i=0; i < ${#word}; i++)); do
       letter=${word:i:1}
       if $consonants == *$letter* ; then
           tmp+=${value[$letter]}
       else
           tmp+=$letter
       fi
   done
   word=$tmp
   # 3. Replace all adjacent same digits with one digit.
   local char
   tmp=${word:0:1}
   local previous=${word:0:1}
   for ((i=1; i < ${#word}; i++)); do
       char=${word:i:1}
       [[ $char != digit: || $char != $previous ]] && tmp+=$char
       previous=$char
   done
   word=$tmp
   # 4. Remove all occurrences of a, e, i, o, u, y except first letter.
   tmp=${word:1}
   word=${word:0:1}${tmp//[AEIOUY]/}
   # 5. If first symbol is a digit replace it with letter saved on step 1.
   [[ $word == digit:* ]] && word=$first${word:1}
   # 6. right pad with zeros
   word+="000"
   echo "${word:0:4}"

}</lang>

If we cheat a bit and allow calling out to `tr`, we can do:

<lang bash>soundex3() {

   local -u word=${1//[^[:alpha:]]/}
   # 1. Save the first letter. Remove all occurrences of 'h' and 'w' except first letter.
   local first=${word:0:1}
   word=$first$( tr -d "HW" <<< "${word:1}" )
   # 2. Replace all consonants (include the first letter) with digits as in [2.] above.
   # 3. Replace all adjacent same digits with one digit.
   local consonants=$( IFS=; echo "${!value[*]}" )
   local values=$( IFS=; echo "${value[*]}" )
   word=$( tr -s "$consonants" "$values" <<< "$word" )
   # 4. Remove all occurrences of a, e, i, o, u, y except first letter.
   # 5. If first symbol is a digit replace it with letter saved on step 1.
   word=$first$( tr -d "AEIOUY" <<< "${word:1}" )
   # 6. right pad with zeros
   word+="000"
   echo "${word:0:4}"

}</lang>

And some testing code:

<lang bash>declare -A tests=(

   [Soundex]=S532     [Example]=E251      [Sownteks]=S532   [Ekzampul]=E251
   [Euler]=E460       [Gauss]=G200        [Hilbert]=H416    [Knuth]=K530
   [Lloyd]=L300       [Lukasiewicz]=L222  [Ellery]=E460     [Ghosh]=G200
   [Heilbronn]=H416   [Kant]=K530         [Ladd]=L300       [Lissajous]=L222
   [Wheaton]=W350     [Burroughs]=B620    [Burrows]=B620    ["O'Hara"]=O600
   [Washington]=W252  [Lee]=L000          [Gutierrez]=G362  [Pfister]=P236
   [Jackson]=J250     [Tymczak]=T522      [VanDeusen]=V532  [Ashcraft]=A261

)

run_tests() {

   local func=$1
   echo "Testing with function $func"
   local -i all=0 fail=0
   for name in "${!tests[@]}"; do
       s=$($func "$name")
       if [[ $s != "${tests[$name]}" ]]; then
           echo "FAIL - $s - $name -- EXPECTING ${tests[$name]}"
           ((fail++))
       fi
       ((all++))
   done
   echo "$fail out of $all failures"

}

run_tests soundex run_tests soundex2 run_tests soundex3</lang>

Output:
Testing with function soundex
0 out of 28 failures
Testing with function soundex2
0 out of 28 failures
Testing with function soundex3
0 out of 28 failures

VBScript

<lang vb>' Soundex

   tt=array( _
     "Ashcraft","Ashcroft","Gauss","Ghosh","Hilbert","Heilbronn","Lee","Lloyd", _
     "Moses","Pfister","Robert","Rupert","Rubin","Tymczak","Soundex","Example")
   tv=array( _
     "A261","A261","G200","G200","H416","H416","L000","L300", _
     "M220","P236","R163","R163","R150","T522","S532","E251")
   For i=lbound(tt) To ubound(tt)
       ts=soundex(tt(i))
       If ts<>tv(i) Then ok=" KO "& tv(i) Else ok=""
       Wscript.echo right(" "& i ,2) & " " & left( tt(i) &space(12),12) & " " & ts & ok
   Next 'i
   

Function getCode(c)

   Select Case c
       Case "B", "F", "P", "V"
           getCode = "1"
       Case "C", "G", "J", "K", "Q", "S", "X", "Z"
           getCode = "2"
       Case "D", "T"
           getCode = "3"
       Case "L"
           getCode = "4"
       Case "M", "N"
           getCode = "5"
       Case "R"
           getCode = "6"
       Case "W","H"
           getCode = "-"
   End Select

End Function 'getCode

Function soundex(s)

   Dim code, previous, i
   code = UCase(Mid(s, 1, 1))
   previous = getCode(UCase(Mid(s, 1, 1)))
   For i = 2 To Len(s)
       current = getCode(UCase(Mid(s, i, 1)))
       If current <> "" And current <> "-" And current <> previous Then code = code & current
       If current <> "-" Then previous = current
   Next 'i
   soundex = Mid(code & "000", 1, 4)

End Function 'soundex </lang>

Output:
 0 Ashcraft     A261
 1 Ashcroft     A261
 2 Gauss        G200
 3 Ghosh        G200
 4 Hilbert      H416
 5 Heilbronn    H416
 6 Lee          L000
 7 Lloyd        L300
 8 Moses        M220
 9 Pfister      P236
10 Robert       R163
11 Rupert       R163
12 Rubin        R150
13 Tymczak      T522
14 Soundex      S532
15 Example      E251

XPL0

<lang XPL0>code CrLf=9, Text=12; string 0; \use zero-terminated strings

func Soundex(S1); \Convert name to Soundex string (e.g: Rubin = R150) char S1; char S2(80), Tbl; int I, J, Char, Dig, Dig0; [ \abcdefghijklmnopqrstuvwxyz Tbl:= "01230120022455012623010202"; I:= 0; J:= 0; \convert all letters to digits repeat Char:= S1(I); I:= I+1;

       if Char>=^A & Char<=^Z then             \convert letter to lowercase
           Char:= Char + $20;
       if Char>=^a & Char<=^z &                \eliminate non letters
          Char#^h & Char#^w then               \eliminate h and w
           [Dig:= Tbl(Char-^a);                \convert letter to digit
           if Dig#^0 & Dig#Dig0 ! J=0 then     \filter out zeros and doubles
               [S2(J):= Dig;  J:= J+1];        \ but always store first digit
           Dig0:= Dig;                         \save digit to detect doubles
           ];

until S1(I) = 0; while J<4 do [S2(J):= ^0; J:= J+1]; \pad with zeros to get 3 digits S2(0):= S1(0) & ~$20; S2(4):= 0; \insert first letter & terminate return S2; \BEWARE: very temporary string ];

int I, Name; [Name:=["Ashcraft", "Ashcroft", "de la Rosa", "Gauss", "Ghosh", "Heilbronn",

       "Hilbert", "Knuth", "Lee", "Lloyd", "Moses", "O'Hara", "Pfister",
       "R2-D2", "Robert", "Rubin", "Rupert", "Tymczak", "Soundex", "Example"];

for I:= 0 to 20-1 do

       [Text(0, Soundex(Name(I)));  Text(0, " ");
       Text(0, Name(I));  CrLf(0);
       ];

]</lang>

Output:
A261 Ashcraft
A261 Ashcroft
D462 de la Rosa
G200 Gauss
G200 Ghosh
H416 Heilbronn
H416 Hilbert
K530 Knuth
L000 Lee
L300 Lloyd
M220 Moses
O600 O'Hara
P236 Pfister
R300 R2-D2
R163 Robert
R150 Rubin
R163 Rupert
T522 Tymczak
S532 Soundex
E251 Example