On 1/25/06, Jeffrey Yasskin
I think it's a neat feature, but:
Using _ seems to conflict with a Jhc extension in which "Using underscore in an expression expands to bottom with an error message giving the current file and line number." http://repetae.net/john/computer/jhc/jhc.html
For one thing, JHC clearly goes beyond Haskell '98 here, and for another, it clearly has no point using syntax where a reserved word would do just fine.
Scheme has a similar feature called (cut) documented at http://srfi.schemers.org/srfi-26/srfi-26.html. I haven't read the SRFI, but it would make sense to incorporate their experience in any new feature for Haskell.
For what I understand from the document, their experience suggests that it is a useful feature, if anything :)
Jeffrey Yasskin
Cheers, Dinko