carljv / soundex

An implementation of the Soundex algorithm in Elixir.

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