As people have suggested on this list, in order to write a haskell program you need to develop a mathematical model which requires some serious up front thinking.  Writing java code on the other hand is more about "coding"  and then "re-factoring".  'Thinking" is discouraged (agile), as the design is more about how you organize your objects for the illusive "reuse" and "future requirements" than anything else.  The approach make sense  if you consider design as an excersize in object organization as you would have better idea on the object organization (aka design) as you plow through the code.

On the other hand if you have a mathematical idea, then a language like java doesn't give you the abstraction tools necessary to implement it as well as a language like Haskell.  But if you don't have a model, then java's approach may be more natural (as is evenident by its popularity)

It seems to me that the two can work side by side if you model your application in  Service Oriented Architecture.   I think the boundries of the services should be thought of as langauges rather than api (function calls).  Two different examples that comes to mind are the SQL and Google Chart.  A Java programmer doesn't care about the SQL Server implementation, but it depends on its query langauge to create the tables, populate them, and issue rather complicated queries on them.     Google Chart is interesting in that it porvideds a language in a URL to implement a service that has been traditionally considered as library.  I would think if you can defines such services in your application then you can define a langaugage and mathematical model around it to implement the service in Haskell. 

Daryoush




--
Daryoush

Weblog: http://perlustration.blogspot.com/