This post originated from an RSS feed registered with Java Buzz by Brian McCallister. Original Post: Closure Recursion in Groovy Feed Title: Waste of Time Feed URL: http://kasparov.skife.org/blog/index.rss Feed Description: A simple waste of time and weblog experiment Latest Java Buzz Posts Latest Java Buzz Posts by Brian McCallister Latest Posts From Waste of Time

Wrote a fun little groovy script earlier today to copy IMAP messages to Exchange. JavaMail and Groovy made this pretty simple, so simple I had to do a bit of gold plating. Oh well =)

The fun part is in this snippet:

traverse = { folder, operation |
    traverse_subfolders = { folder, operation |
        recur = this
        folder.list().each { 
            operation(it)
            recur(it, operation)
        }
    }
    operation(folder)
    traverse_subfolders(folder, operation)
}

Groovy suffers from a cannot-call-closure-by-name-from-itself problem. Because the closure is a first class object though, you have access to it via this, so you can, in fact, recur on your closure.