[Haskell-cafe] Process properties as global values

Jan-Willem Maessen - Sun Labs East Janwillem.Maessen at Sun.COM
Mon Jul 12 13:10:36 EDT 2004

Alastair Reid wrote:
>>I'm just wondering, why haven't process properties (such as the command
>>line arguments, or the parent process id), which are inherently global,
>>been made global values in the Haskell standard? You could avoid
>>needlessly carrying around these values, you wouldn't need to lift some
>>functions into the IO monad...
> This is true and you don't break purity and common programming tasks become a 
> bit easier because you need less plumbing.  One argument against doing so is 
> that it will make data dependencies less obvious.

An ironic historical footnote here: Back in the ancient days, only hbc 
provided access to command line arguments and environment variables, 
and it did so through a global.

The argument on this subject happened back then, too  (in the early 
days of the Haskell mailing list!).  I have no idea if there are 
archives from back then...

-Jan-Willem Maessen

More information about the Haskell-Cafe mailing list