The Haskell Report

Simon Peyton-Jones [email protected]
Mon, 23 Jul 2001 09:49:42 -0700


You may be right, but the Report is neither confusing nor inconsistent
on this point, I think.  So I don't think it falls into the class of
things
that we can change for H98.

You'll just have to add parens!

Simon

| -----Original Message-----
| From: Ch. A. Herrmann [mailto:[email protected]]=20
| Sent: 23 July 2001 15:04
| To: [email protected]
| Subject: The Haskell Report
|=20
|=20
| Hi Haskellers,
|=20
| because I recognized that some people are discussing
| the Haskell report, I'd like to point out a problem
| concerning the operator precedences.
|=20
| At precedence level 9, there are the left associative
| operator (!!) and the right associative operator (.),
| but combining both directions doesn't make sense neither for me ..
|=20
| .. nor for ghci:=20
|    > gs !! i . f
|    > cannot mix `(!!)' [infixl 9] and `(.)' [infixr 9] in the=20
| same infix expression
| =20
| It appears sensible for me that (!!) associates to the
| left and I suppose that there is a strong requirement
| for (.), which is associative anyway (f.g).h =3D f.(g.h),=20
| to associate to the right, due to efficiency reasons.
| However, what's the problem with introducing a precedence=20
| level 10 and move (!!) upto it?
|=20
| Cheers
| Christoph
|=20
| _______________________________________________
| Haskell mailing list
| [email protected] http://www.haskell.org/mailman/listinfo/haskell
|=20