Doc/lib/libsoundex.tex

   1 \section{Built-in Module \module{soundex}}
   2 \label{module-soundex}
   3 \bimodindex{soundex}
   4
   5
   6 The soundex algorithm takes an English word, and returns an
   7 easily-computed hash of it; this hash is intended to be the same for
   8 words that sound alike.  This module provides an interface to the
   9 soundex algorithm.
  10
  11 Note that the soundex algorithm is quite simple-minded, and isn't
  12 perfect by any measure.  Its main purpose is to help looking up names
  13 in databases, when the name may be misspelled --- soundex hashes common
  14 misspellings together.
  15
  16 \begin{funcdesc}{get_soundex}{string}
  17 Return the soundex hash value for a word; it will always be a
  18 6-character string.  \var{string} must contain the word to be hashed,
  19 with no leading whitespace; the case of the word is ignored.  (Note
  20 that the original algorithm produces a 4-character result.)
  21 \end{funcdesc}
  22
  23 \begin{funcdesc}{sound_similar}{string1, string2}
  24 Compare the word in \var{string1} with the word in \var{string2}; this
  25 is equivalent to
  26 \code{get_soundex(\var{string1})} \code{==}
  27 \code{get_soundex(\var{string2})}.
  28 \end{funcdesc}
  29
  30
  31 \begin{seealso}
  32
  33 \seetext{Donald E. Knuth, \emph{Sorting and Searching,} vol. 3 in
  34 ``The Art of Computer Programming.'' Addison-Wesley Publishing
  35 Company:  Reading, MA: 1973. pp.\ 391-392.  Discusses the origin and
  36 usefulness of the algorithm, as well as the algorithm itself.  Knuth
  37 gives his sources as \emph{U.S. Patents 1261167} (1918) and
  38 \emph{1435663} (1922), attributing the algorithm to Margaret K. Odell
  39 and Robert C. Russel.  Additional references are provided.}
  40
  41 \end{seealso}