Allow configuration of error message printing
This MR implements the idea of #21731 (closed) that the printing of a diagnostic method should be configurable at the printing time.
The interface of the Diagnostic
class is modified from:
class Diagnostic a where
diagnosticMessage :: a -> DecoratedSDoc
diagnosticReason :: a -> DiagnosticReason
diagnosticHints :: a -> [GhcHint]
to
class Diagnostic a where
type DiagnosticOpts a
defaultDiagnosticOpts :: DiagnosticOpts a
diagnosticMessage :: DiagnosticOpts a -> a -> DecoratedSDoc
diagnosticReason :: a -> DiagnosticReason
diagnosticHints :: a -> [GhcHint]
and so each Diagnostic
can implement their own configuration record which can then be supplied by a client in order to dictate how to print out the error message.
At the moment this only allows us to implement #21722 (closed) nicely but in future it is more natural to separate the configuration of how much information we put into an error message and how much we decide to print out of it.
Edited by sheaf