On 24-02-2015 11:15, Joachim Breitner wrote:
Hi,
Am Dienstag, den 24.02.2015, 11:11 +0100 schrieb Henning Thielemann:
On Mon, 23 Feb 2015, Erik de Castro Lopo wrote:
The idea would be to deprecate fromMaybe for 7.12 and remove it completely later.
I would deprecate it, but not remove it. Otherwise people will think that this obvious function is missing by accident. We would then encounter various discussions about adding it in the close future.
-1 to the original proposal. Obviously -- it would cause far too much breakage for very little upside.
that’s a more useful idea, but again: Why fromJust and not head etc..?
If you would continue this thought of line towards some consistency, then we’d need a way to annotate partial functions in general, and have a dedicated flag -fwarn-partial-functions. (It would behave just like deprecations – but reported separately.). This would go well with -fwarn-incomplete-patterns. Such a thing might be useful.
Yes, this would definitely be useful. (Should perhaps be turned on by default for non-ghci? That might usefull help prod unaware people in the direction of total functions.) Then in 2020 or 2025 or so someone could do a survey of github/hackage to see what the breakage would be from actually froming fromJust, &c. Regards,