Haskell report (August release)
Fri, 28 Sep 2001 05:48:47 -0700
A reasonable suggestion, but I'm afraid I don't want
to make structural changes to the Report.
| -----Original Message-----
| From: Mark Tullsen [mailto:email@example.com]=20
| Sent: 27 September 2001 20:35
| To: Simon Peyton-Jones
| Cc: firstname.lastname@example.org
| Subject: Re: Haskell report (August release)
| Here's a minor quibble with the organization of the Report=20
| and Library, not with the content. Sorry if this has been=20
| brought up before.
| In section 4.3.3, Derived Instances, of the Report there is
| The only classes in the Prelude for which derived instances are
| allowed are Eq, Ord, Enum, Bounded, Show, and Read, all mentioned in
| Figure 5, ... Classes defined by the standard libraries may also be
| In the introduction to the Library Report there is
| Classes defined in libraries may be derivable. This report includes
| the derivation of such classes when appropriate.
| Now, unless I missed something, the only class in the Library=20
| Report which is derivable is Ix.
| I would argue for bringing the Ix class into the Report for=20
| these reasons
| * One does not have to search through the Library Report to=20
| what is derivable.
| * I think one would expect that the Libraries contain stuff=20
| that could be
| implemented in Haskell by the user. Until Haskell has=20
| the ability=20
| to allow for user-defined derivable classes, Ix cannot be
| defined by the user.
| - Mark