Re: ghc should be able to deduce correct use of partial functions and not give a warning in such cases
Mark McConnell via Haskell-Cafe <[email protected]>
| Newsgroups | gmane.comp.lang.haskell.cafe |
|---|---|
| Message-ID | <[email protected]> |
This is what I was going to say. The original poster is right, but still, null is a function. It is one level of indirection away from pattern matching.
On Tuesday, April 16, 2024 at 10:46:56 AM EDT, Henning Thielemann <[email protected]> wrote:
On Tue, 16 Apr 2024, George Colpitts wrote:
> ghc should be able to deduce correct use of partial functions and not give a warning in such cases, e.g.
> in 9.8.2
>
> if null ys then [] else [(xs,tail ys)])
>
> gets a warning
>
> warning: [GHC-63394] [-Wx-partial]
>
> but it is clear that this use of tail will never be a problem so IMHO that line of code should not get a
> warning.
>
> Does anybody know if there is a plan or enhancement request to eliminate such warnings?
I would just use good old pattern matching:
case ys of
[] -> []
_:zs -> [(xs,zs)]_______________________________________________
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