Generalized phase control for GHC

[Simon Peyton-Jones]

| giving up. Admittedly I only have a superstition that this will be a
| practical problem.

I agree with Roman -- let's not bother with lenience until we need it

| > Secondly, I think it is quite
| > important to be able to specify dependencies for already declared phases.
| > That is, I (probably) want to be able to say in module C that phase X from
| > module A should come before phase Y from module B.
|
| This in interesting. You're right that it's not possible with this
| system: to support this you would need a more class + instance rather
| than single declaration flavour for phases. Do you have a practical
| example in mind of how you would use it?

Ah -- Roman you mean you want to add a phase-ordering constraint at some time *other* than when you declare one or other of the phases.  Are you sure this is important?  It's an awkward addition because, like orphan instances, it means there's an interface file with perhaps-vital info which you might have no other reason to visit.

Also, why do you want phase aliases?

Simon