[Haskell] No Pattern Guards

Malcolm Wallace Malcolm.Wallace at cs.york.ac.uk
Mon Mar 28 08:56:13 EST 2005

John Meacham <john at repetae.net> writes:

> Oddly enough, I was looking over the old Haskell discussions, and
> pattern guards were supposed to make it into Haskell 98 according to the
> decision. Any idea what happened? did someone just forget to write them
> up or was there further discussion elsewhere? Old mailing list archives
> seem to be hard to come by.
>  http://www.cs.chalmers.se/~rjmh/Haskell/Messages/Decisions.cgi

The Haskell'98 committee discussion /started/ on that message board,
but unfortunately it records neither the complete discussion, nor the
real final decisions.  For various personal reasons, the editorship of
the standard passed from John Hughes to Simon Peyton Jones towards the
end of 1997.  I believe the remainder of the discussions and decisions
were made in public on the Haskell mailing list.  Simon kept a firm
hand on the tiller, sticking closely to the mandate for Standard Haskell,
namely to fix bugs, remove traps for the unwary, and lift restrictions.
New extensions were explicitly excluded.

To find list archives for the relevant period (Jan-Dec 1998), you will have
to search at <http://mail-archive.com/haskell@haskell.org/>.  There does not
appear to be an easy way to get a date-sorted segment of the archive
without clicking 'earlier' several hundred times.  :-(

Here is at least some of the discussion on pattern guards:


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