Beginner: error when using multiple where stmts in hugs98
Matthias Kilian
kili@outback.escape.de
Fri, 1 Dec 2000 22:28:37 +0100 (CET)
On Fri, 1 Dec 2000, Guy Lapalme wrote:
> this explanation is very good but the real confusion comes from the fact
> that probably there were some TAB characters in the original program. In =
the
> text editor used for typing the program the tabs stops were 4 spaces apar=
t
> as they are usually nowadays because otherwise programs become too wide..=
=2E
>
[...]
>
> Concrete suggestions about this any one?
Nothing which has to with Haskell, but:
I think it's a bad idea to expand tabstops to something other then the
"standard" (historic?) positions, i.e. 8 spaces apart. Nearly every editor =
can
handle indentation independent of the TAB character, for example indentatio=
n
in vi (^T) uses the parameter "shiftwidth" for indentation. Then, *leading*
spaces are compressed to tabstops, if appropriate. For example,
=09 this line has been indented three times with ^T,
where shiftwidth is 4. The line should start with a tabstop, followed by 4
spaces.
Regarding to the layout rule, many people think that it's a horror from a
sound syntax lover's point of view. Some years ago, when I wrote a Haskell
parser for fun, I shared this opinion.
However, although the layout rule is a nightmare to implement, it makes als=
o
Haskell programs not only easy to read, but sometimes to look even beautyfu=
l
(wrt to programs in other languages).
Bye,
=09Kili
ps: apropos beauty of programs: does anyone here ever heared of the
language called "J"?
--=20
Nunja! Wenn man erst einmal anf=E4ngt zu denken, dann ist es wie
eine Sucht. Man kommt nicht mehr los davon.
[WoKo in dag=B0, 28.11.2000]