@Simon, The route you outline was the one we already use -- but that gives back the full name "Data.Set.Base.Set" (instead of "S.Set" or "Data.Set.Set"), as the module is "Data.Set.Base".
@Edward, Yes, I think your suggestion should work! This business of determining which packages/modules are hidden is exactly what we are trying to get around. (In this case, Data.Set.Base is hidden...) Thanks all! - Ranjit. On Wed, Jan 25, 2017 at 1:00 AM, Edward Z. Yang <ezy...@mit.edu> wrote: > Hi Ranjit, > > Unfortunately you need more information to do this, since the > set of modules which are available for import can vary depending > on whether or not packages are hidden or not (not even counting > whether or not a module is exposed or not!) > > The way GHC's pretty printer gives a good name is that it keeps > track of all of the names in scope and where they came from > in a GlobalRdrEnv. The relevant code is in 'mkPrintUnqualified' > in HscTypes, but if you pretty print using user-style with > an appropriately set up GlobalRdrEnv you should > get the things you want. > > Edward > > Excerpts from Ranjit Jhala's message of 2017-01-24 19:00:05 -0800: > > Dear Joachim, > > > > You are right -- some more context. > > > > Given > > > > tc :: TyCon > > m :: ModName > > env :: HscEnv > > > > I want to get a > > > > s :: String > > > > such that _in_ the context given by `m` and `env` I can resolve `s` to > get > > back the original `TyCon`, e.g. something like > > > > L _ rn <- hscParseIdentifier env s > > name <- lookupRdrName env modName rn > > > > would then return `name :: Name` which corresponds to the original > `TyCon`. > > > > That is, the goal is _not_ pretty printing, but "serialization" into a > > String > > representation that lets me recover the original `TyCon` later. > > > > (Consequently, `"Data.Set.Base.Set"` doesn't work as the `Data.Set.Base` > > module is hidden and hence, when I try the above, GHC complains that the > > name is not in scope. > > > > Does that clarify the problem? > > > > Thanks! > > > > - Ranjit. > > > > > > On Tue, Jan 24, 2017 at 6:11 PM, Joachim Breitner < > m...@joachim-breitner.de> > > wrote: > > > > > Hi Ranjit, > > > > > > Am Dienstag, den 24.01.2017, 16:09 -0800 schrieb Ranjit Jhala: > > > > My goal is to write a function > > > > > > > > tyconString :: TyCon -> String > > > > > > > > (perhaps with extra parameters) such that given the > > > > `TyCon` corresponding to `Set`, I get back the "original" > > > > name `S.Set`, or even `Data.Set.Set`. > > > > > > > > Everything I've tried, which is fiddling with different variants of > > > > `PprStyle`, end up giving me `Data.Set.Base.Set` > > > > > > > > Does anyone have a suggestion for how to proceed? > > > > > > in a way, `Data.Set.Base.Set` is the “original”, proper name for Set, > > > everything else is just a local view on the name. > > > > > > So, are you maybe looking for a way to get the “most natural way” to > > > print a name in a certain module context? > > > > > > This functionality must exist somewhere, as ghci is printing out errors > > > this way. But it certainly would require an additional argument to > > > tyconString, to specify in which module to print the name. > > > > > > Greetings, > > > Joachim > > > > > > > > > -- > > > Joachim “nomeata” Breitner > > > m...@joachim-breitner.de • https://www.joachim-breitner.de/ > > > XMPP: nome...@joachim-breitner.de • OpenPGP-Key: 0xF0FBF51F > > > Debian Developer: nome...@debian.org > > > _______________________________________________ > > > Glasgow-haskell-users mailing list > > > Glasgow-haskell-users@haskell.org > > > http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users > > > > > > >
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