converting capital letters into small letters

[Andy Moran]

Andrew J Bromage wrote:

> G'day all.

Avagoodweekend.

> On Fri, Jul 26, 2002 at 01:27:48AM +0000, Karen Y wrote:
> > 1. How would I convert capital letters into small letters?
> > 2. How would I remove vowels from a string?
>
> As you've probably found out, these are very hard problems.

i agree, and I also agree that Haskell hasn't got it quite right. Luckily=
 for=20
us, this problem has been around for a while now, and a solution may be f=
ound=20
in a C library, known as "ctype.h".  It provides this function:

       int tolower(int c);

So with a little foreign import magic, and a bit of map (details left to=20
reader), we're golden!  Caveat: this doesn't necessarily work for Unicode=
,=20
but it's a start.  And you've got to stay within the IO monad.  But them'=
s=20
the breaks.

As for removing vowels, instead of proposing a solution, I choose to disp=
ute=20
that the problem needs solving and claim victory.

Cheers,

Andy

--=20
Andy Moran                                              Ph.  (503) 526 34=
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