[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...
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