[Haskell-cafe] how unsafe is this?

[Ben Clifford]

I've defined a helper function to let me do regexps in functional style:

> sed exp str = unsafePerformIO $ do
>  regexp <- regcomp exp 0
>  regexec regexp str

Is this always safe? or where is it not?

(I'm using any one regexp more than once so it doesn't bother me that it 
compiles each time)

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