[Haskell-cafe] Re: [Haskell] Top Level <-
ganesh at earth.li
Sun Aug 31 10:29:35 EDT 2008
On Sun, 31 Aug 2008, Brandon S. Allbery KF8NH wrote:
> On 2008 Aug 31, at 10:20, Ganesh Sittampalam wrote:
>> I'm not sure of precisely what you mean here, but stdin, stdout and
>> stderr are things provided by the OS to a process. That's what defines
>> them as having process scope, not something the Haskell language or RTS
> But their representations in Haskell must have the same scope and are
> therefore de facto global variables.
Yep, but this is not Haskell providing a way to make global variables, it
is just providing an interface to ones that already exist. The point is
that the RTS can't provide (process-scope) global variables of its own
invention, because it can't guarantee to be running at the top-level of a
process, which it needs to be in order to control their construction.
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