[jira] Commented: (CODEC-57) Metaphone.metaphone(String) returns an empty string when passed the word "why".

["Henri Yandell (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CODEC-57?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12560781#action_12560781 ] 

Henri Yandell commented on CODEC-57:
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Looking at the code; the first step it does is turn the WH into a W. 

Then later on, both W and Y are silent if they are not followed by a vowel.

Playing with the link above, it looks like WH is turned into H there. A quick look at the source code to PHP shows that it is indeed converted to H. Another quick look, this time at text.rubyforge shows that the Ruby version converts to W as we do [though it claims to compare with the PHP version for differences]. 

Looking at DoubleMetaphone, it handles WH differently. If ^WH, then it'll append an A.

Looking at the original BASIC code [as posted by aspell.sf.net]:

IF TWO = "WH" THEN ENAME = "W":ENAME[3,9999]

So it looks like PHP are the one with the bigger bug - a surname of WHYE should be YE and not HE. Then it seems that Metaphone itself is weak in that (my opinion) it should consider 'Y' a vowel when looking after 'W' for a vowel. 

I'm not sure what we should do though. The documentation at http://text.rubyforge.org/svn/lib/text/metaphone.rb also indicates that there are other bugs in the original BASIC compared to the original discussion (anyone got that magazine article? :) ). So this might just be a bug in the BASIC implementation rather than the original algorithm.

> Metaphone.metaphone(String) returns an empty string when passed the word "why".
> -------------------------------------------------------------------------------
>
>                 Key: CODEC-57
>                 URL: https://issues.apache.org/jira/browse/CODEC-57
>             Project: Commons Codec
>          Issue Type: Bug
>    Affects Versions: 1.3
>         Environment: Commons-codec built from source using jdk 1.4.2.
> OS: Windows XP
> Java Build: 1.4.2
>            Reporter: Adam Wilmore
>             Fix For: 1.4
>
>
> An empty string is returned from the Metaphone.metaphone(String) method when passed the value "why". Variations on the value, such as "wwwhy" and "wwhhhy" also return empty strings.
> This appears to be an issue since other implementations of the metaphone algorithm, namely the PHP version, returns "H" when passed the value "why".

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