S. Alexander Jacobson writes:
> In principle I can do this, but:
> 1. how do I hide the import of show String to replace it w/ my own?
> 2. If I do replce show String what else will break?
I'd rather let the preprocessor insert calls to eshow, and leave show
as it is.
> 3. If instead I define an eshow function that strips "", how do I minimize
> the perforamnce hit of quote stripping?
Maybe you could make eshow a member in a class EShow, which defaults
to show, and make a special instance for Char (add a member eshowList).
> 4. If I want to share my code, I have to share both the actual codebase as
> well as the preprocessor code. This seems like sucha basic language
> syntax issue that I shouldn't have to worry about which version of haskell
> your collaborators are running. Everyone writing their own preprocessor
> will severely balkanize the language.
I think it's a good idea to use a preprocessor for experimenting with
your own language extensions. When (and if) the extensions settle and
turn out to be useful, you could consider proposing them as part of a
language definition.
> 5. How does the use of this pre-processor interact w/ tools like Derive
> and PolyP which are also implemented as preprocessors?
I don't know. Buth the HacWrite preprocessor is simpleminded, it only
looks for the new text lexemes, and doesn't know about the Haskell
syntax. If you run such a preprocessor first, I think it would work.
> That being said, I would be happy to take a shot at HacWrite if it had a
> shot of becoming part of the language definition (or if it was a standard
> part of the various haskell distributions: ghc, hugs, hbc,etc.) and if
> Magnus would allow it.
>
> Is there a good lanugage reason to object to this feature? It seems like
> a no brainer imprpovement.
I don't see any need to put something like this into the language
definition for the moment. But if you want to use HacWrite, I could
try to put it on some web page.
/M
>
> -Alex-
>
>
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> On Tue, 8 Jun 1999, Lennart Augustsson wrote:
>
> > "S. Alexander Jacobson" wrote:
> >
> > > HacWrite certainly seems like an improvement over Haskell.
> > > However, it is just not as good as the scripting languages.
> > > HacWrite still requires the author to differentiate between strings and
> > > other types, still requires explicit use of show and still requires more
> > > typing and curly balancing. Isn't this nicer?
> > >
> > > "insert into mytable values (NULL,'$var1','$(var2+var3)','$var3')
> > >
> >
> > So add your own little modification to HacWrite. It would be easy enough
> > to add $ interpolation.
> >
> > -- Lennart
> >
> >
