Is this a weird compiler bug or am I missing something?

ntwilson · June 23, 2021, 4:12am

Sorry that this isn’t the smallest repro example you’ve ever seen. I’ve got a compiler error that I don’t think should be an error:

If I switch the order of my successfulAttempts/failedAttempts binding and wasSuccessful, then it compiles, but I get a warning:

but of course if I replace yes: successfulAttempts with yes: _, I get another error

My understanding is that either of the top two images should have compiled without any errors or warnings. Can somebody help me understand what’s going on?
The repro can be found at purs-syntax-err/Main.purs at main · ntwilson/purs-syntax-err · GitHub

ntwilson · June 23, 2021, 4:13am

I’m able to get it working without any warnings at all with this very specific setup:

kritzcreek · June 23, 2021, 8:23am

I think this is another instance of this compiler bug.

ntwilson · June 23, 2021, 2:31pm

Is the warning for “name … introduced but not used” part of that same bug? I can’t get the warning to go away just by reordering statements (I did get it to go away by splitting my declarations between let bindings and where bindings)

garyb · June 23, 2021, 8:44pm

I think that warning would be this bug, which should now be fixed for the next release thanks to @nwolverson.

nwolverson · June 23, 2021, 10:32pm

The warning is indeed the issue just fixed; if the binding ordering is considered to be a bug and fixed that warning will need to be fixed again, to my shame - I’ll make a note on that issue.