"Ronald J. Legere" wrote:
>
> SUMMARY: How about a supplement to the standard that contains the
> 'standard' extensions that everyone uses.
One problem I have with this is that "unsafe" operations, being unsafe,
are difficult to fit in with the rest of the language. For example
a common use of unsafePerformIO is to set up global variables:
counter :: MVar Int
counter = unsafePerformIO(newMVar 0)
What exactly does this mean? I presumably want only one counter for the
whole program. But what is a program? Suppose "counter" is declared as
part of a "where" clause in a bigger function. Is the compiler allowed
to lift it so that there is only one counter, or should it create only one?
And so on. I think the current situation, where such functions are only
supplied as extensions with "caveat emptor" implied, is probably best.
I agree with Lennart Augustsson that such features are best avoided
completely if reasonably possible, but for me this would not be easy.
A possible way out would be the extension of Haskell to include
those implicit variables someone recommended a while back . . .
