Soundex

An module for computing the Soundex codes of strings.

Soundex is an algorithm for representing (mainly English) names as short phonetic codes. A Soundex code begins with the first letter of the name, followed by three digits. They are typically used to match like-sounding names.

For more information, see the Wikipedia entry.

Examples:

iex> Soundex.soundex("Morris")
"M620"

iex> Soundex.soundex("Harris")
"H620"  

iex> Soundex.soundex("Morrison")
"M625"

iex> Soundex.soundex("Smith")
"S530"

iex> Soundex.soundex("Smithie")
"S530"           

Details

Soundex only encodes letters from the English alphabet. So, for example, punctuation in names is ignored:

iex> Soundex.soundex("O'Brien") == Soundex.soundex("OBrien")
true

As are spaces:

iex> Soundex.soundex("Van Dyke") == Soundex.soundex("Vandyke")

Unicode letters are also ignored:

iex> Soundex.soundex("Piñata") == Soundex.soundex("Pinata")
false

iex> Soundex.soundex("Piñata") == Soundex.soundex("Piata")
true

One exception to this is the German esszet, which Unicode treats as two S's:

iex> Soundex.soundex("Straßer") == Soundex.soundex("Strasser")
true