Doesn't Haskell already implement the 3-valued logic (True, False, NULL), that Karl Fant proposes (see papers at http://www.theseusresearch.com/invocation%20model.htm) as an alternative to centralised clock-based coordination, by postulating that every data type includes the bottom value? I like his concept that: "concurrency is simple and primitive and sequentiality is a complex and risky derivative of concurrency." Can someone remind me why, in a language like Haskell that is referentially transparent and therefore inherently 'concurrent', we need explicit concurrency (threads, etc.) ? titto On Monday 09 July 2007 06:48:03 Donald Bruce Stewart wrote:
drtomc:
I don't know if you saw the following linked off /.
http://www.itwire.com.au/content/view/13339/53/
An amazon link for the book is here:
http://www.amazon.com/Computer-Science-Reconsidered-Invocation-Expression /dp/0471798142
The basic claim appears to be that discrete mathematics is a bad foundation for computer science. I suspect the subscribers to this list would beg to disagree.
Enjoy,
:-)
And he's patented it...
http://www.patentstorm.us/patents/5355496-description.html
SUMMARY OF THE INVENTION
A method and system for process expression and resolution is described. A first language structure comprising a possibility expression having at least one definition which is inherently and generally concurrent is provided. Further, a second language structure comprising an actuality expression including a fully formed input data name to be resolved is provided. Furthermore, a third language structure comprising an active expression initially having at least one invocation, the invocation comprising an association with a particular definition and the fully formed input data name of the actuality expression is provided. Subsequently, the process of resolving invocations begins in the active expression with fully formed input data names in relation to their associated definition to produce at least one or both of the following: (1) an invocation with a fully formed input data name and (2) a result data name.
Interesting...
-- Don _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe