At 17:35 +0000 1999/01/20, Mark P Jones wrote:
>| With regard to this, I would like to suggest the addition of a new
>| command (:v) which could give the version number to the user...
..
> - Is a command the best way to provide this functionality? For
> example, if there was a standard library with a signature:
>
> module Haskell where -- Possible values:
> systemName :: String -- "Hugs", "GHC", "hbc", "nhc", "qhc",...
> haskellVersion :: Int -- 3, 14, 98, 99, 2000, 2, ...
> releaseDate :: Date -- ...
> version :: String -- some combination of the above
>
> then programs would be able to inspect and test which version of
> Haskell they were using at run-time, and a user could just evaluate
> Haskell.version in a Hugs session to find out which version they
> were using. Something like this might also form the basis for a
> conditional compilation mechanism, although that needs more thought
> and more careful design.
I think this is definitely the way, because I have encountered people
trying to combine different version number Hugs and Preludes (which does
not work).
I think this should be added to Haskell, so that the compiler can give an
error message at startup time. One can even think of giving Prelude files a
checksum number, so that the compiler can detect if the prelude file has
been changed, and give a warning if so is the case.
Hans Aberg
* Email: Hans Aberg <mailto:[EMAIL PROTECTED]>
* Home Page: <http://www.matematik.su.se/~haberg/>
* AMS member listing: <http://www.ams.org/cml/>
