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Haskell Playground
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Is it possible to show the warning #38

Closed jappeace closed 1 year ago

jappeace commented 1 year ago

Feature request

I was trying to figure out if it's possible to add a warning to just an instance of a typeclass https://play.haskell.org/saved/4eguwdkk

however it appears af if the playground doesn't emit any warnings at all, I also added an unused module Data.Set and the playground doesn't emit this.

It'd be nice if it did this as well.

tomsmeding commented 1 year ago

however it appears af if the playground doesn't emit any warnings at all, I also added an unused module Data.Set and the playground doesn't emit this.

This is resolved by putting {-# OPTIONS -Wall #-} at the top of your program. :)

I guess you're suggesting to enable -Wall by default. I'm not sure this is a good idea, though I am a firm proponent of -Wall. I wonder what group would be good to poll on this.

Re your WARNING pragma: quoting from the docs we find:

Warnings and deprecations are not reported for (a) uses within the defining module, (b) defining a method in a class instance, and (c) uses in an export list. The latter reduces spurious complaints within a library in which one module gathers together and re-exports the exports of several others.

so this is expected behaviour.

jappeace commented 1 year ago

yeah, I need a seperate module, thanks anyway. -Wall makes it emit warings.