Give civilised error messages when desugaring Template Haskell brackets
DsMeta fails with a panic if it encounters something it can't desugar into TH syntax. This is bad: the error should be civilised. But there's no current provision for desugarer *errors*, only *warnings*.
Add errors, and perhaps promote the error/warning box into the part that is shared between all uses of IOEnv (renamer, typechecker, desugarer)
Nothing hard, a bit tedious.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 6.4.1 |
| Type | Task |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | Unknown |
| Architecture | Unknown |