[Haskell-cafe] Re: looking for origin of quote on
preprocessors and language design
uzytkownik2 at gmail.com
Wed Jan 13 16:54:59 EST 2010
On Wed, 2010-01-13 at 22:42 +0100, Henning Thielemann wrote:
> Maciej Piechotka schrieb:
> > Not quite. While I agree that "the *frequent* need for a preprocessor
> > shows omissions in (the design of) a language." it is not necessary the
> > case. Preprocessor may be useful if:
> > - there is a new beatyful feature in newer version of compiler but you
> > still want to have backward compatibility.
> > - there are compiler or platform dependant elements. For example if you
> > write a driver in Haskell you may want to share code as much as possible
> > but you need to know 1) the size of registers and 2) the platform you're
> > writing as Windows have quite different API then Linux or BSD.
> > - You need to enable/disable features at build-time. It is not frequent
> > at closed-source system but it is frequent on OpenSource systems. For
> > example I might need to have minimal program for embedded system but
> > with full feature set it likly conquer the desktops
> Many of these problems are solved by preprocessor intervention in C/C++,
> but there is often no need to do so. You could also write system
> dependent modules, where the right module for your system is included by
> the build system. I hope the build system does not count as a
> preprocessor. In Haskell it is however still no fun to support multiple
> versions of the base libraries, not to speak of different compilers -
> and their set of libraries.
> Unfortunately, the original question is still not answered.
Hmm. May I ask how to do for example something depending on POSIX or
WinAPI? I am sorry but I cannot see how any of the above problems could
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Size: 198 bytes
Desc: This is a digitally signed message part
Url : http://www.haskell.org/pipermail/haskell-cafe/attachments/20100113/e6e917f7/attachment.bin
More information about the Haskell-Cafe