monad library

Iavor Diatchki
Thu, 31 Jul 2003 17:07:56 +0000


Simon Marlow wrote:
> So are you saying that it won't break much code, or it won't break any
> code?  Either way, I'd be happy for it to be brought in without
> providing the old version - we make minor changes to library APIs all
> the time (only in new major releases of GHC, though).
unfortunately it is not 100% compatable with the old library and some 
code will probably be broken.  the more important changes are described 
in the README file in CVS, and also most of the library is documented
(one could always write more of cousre :-)
in short the main changes are probably the behaviour of "listen" in 
general, and the definitions of "fail","mzero", and "mplus" for some of 
the transformers  (Error in particular).  also since there are some new 
functions, they could clash with already existing names in a module. 
and the module structure is changed to "column" format rather than the 
"diagonal" used in the old library.  so i think code may break or not 
depending on what exactly was used, but it should not be hard to fix. 
of course people don't usually want to go and fix old code.


| Iavor S. Diatchki, Ph.D. student               |
| Department of Computer Science and Engineering |
| School of OGI at OHSU                          |
|               |