Christopher Done
Hi all,
I'm attempting to make a simple evaluator for GHC core, but I'm not clear on how to reliably looking up names. I'm compiling each of ghc-prim, integer-simple and base with a patched version of GHC which performs an extra output step with the Core AST to a file for each module.
...
Two questions:
1) How do I recognize class methods when I see one, like the "main:Main:foo" above?
Maybe this? isClassOpId_maybe :: Id -> Maybe Class
Is an "op" what GHC calls type-class methods?
Yes, I believe this will do what you are looking for.
2) If I compile e.g. ghc-prim and that generates a binding Name with ID 123, and then I compile base -- will the ID 123 be re-used by base for something else, or will any reference to 123 in the compiled Names for base refer ONLY to that one in ghc-prim? In other words, when GHC loads the iface for ghc-prim, does it generate a fresh set of names for everything in ghc-prim, or does it load them from file?
Perhaps I am misunderstanding Csaba's point, but I don't believe you can rely on uniques here. Except in the case of known key things (which is certainly the minority of things), uniques are generated afresh with every GHC compilation. While it's possible that the same compiler run will happen to produce the same Name/Unique correspondence, this is not guaranteed and may be broken by GHC `-j`, different recompilation-checker conditions, etc. The only part of the name that we guarantee will be stable across compiler sessions is the OccName of Names coming from interface files. The uniqueness of these names is ensured when we create the interface file by TidyPgm.chooseExternalIds. In principle you could do something similar to the entire Core program before you dump it. Cheers, - Ben