`ApplicativeDo` needlessly uses `join` too much
foo = do
A 1
B 2
C 3
return () produces very different code than
foo = do
A 1
B 2
C 3for no good reason. Currently we check to see if the last clause is a return or something else, and then bolt a join in if it isn't return. But this check is too conservative. If it isn't a return but doesn't reference any of the variables above, you can still desugar it with (<*>).
We found this during a twitch livestream in front of an audience of 127 people. =)
Trac metadata
| Trac field | Value |
|---|---|
| Version | 8.4.2 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler (CodeGen) |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |