Top Level TWI's again was Re: [Haskell] Re: Parameterized Show
benjamin.franksen at bessy.de
Tue Nov 23 06:46:25 EST 2004
On Tuesday 23 November 2004 10:39, Keean Schupke wrote:
> Adrian Hey wrote:
> >This is one situation, but certainly not the only possible one. You have
> >the same problem with interfacing to any unique stateful resource (or
> >even if you have a multiple but finite supply of these resources).
> No you don't... Most devices have registers, those registers contain
> values, you can inspect those values to see if the device has been
> initialised. You can then write a guard on the initialisation that really
> checks if the device has (or hasn't) been initialised rather than rely
> on some
> 'shadow' copies in RAM.
Alas, unfortunately not every device is designed in this way (I can give
examples if you want). Adrian is right in that there is not only badly
designed C libraries but also badly designed hardware!
Top level things with identity are evil. -- Lennart Augustsson
More information about the Haskell