Purging files by wildcard? Why doesn't 'tidy' have a purge attribute?

[pokemon.mas...@gmail.com]

  I'm on puppet 4.3.2 and having a difficult time trying to remove unmanaged files that follow a wildcard.  There are two options for removing files:

• The file resource, with an 'ignore' attribute and a purge attribute.  Ignore works well when you know the list of files you don't want to remove.  But since it's using ruby-globbing, using negation to only ignore files that don't contain a specific word is impossible
• The tidy resource, with a 'matches' attribute.  This give me the ability to specify a wildcard of what to remove but it doesn't have a 'purge' attribute, so it will even remove managed files.

  Am I missing something?