#11970: Simplify Parent for patten synonyms -------------------------------------+------------------------------------- Reporter: simonpj | Owner: mpickering Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by mpickering): Firstly, Simon and I talked this morning about this and he suggested my problem was because the constructor names were in the wrong namespace. His hunch was correct. However, there is an unforseen problem with this approach. Say that both modules `M` and `N` export symbols which have the same name, if one of them is a record selector and we try and export it with its parent then we can an ambiguous name warning. Concretely {{{ module M where data T = T { f :: Int } }}} {{{ module N where f = "f" }}} {{{ module Foo (T(f)) where import M import N }}} In this example, `f` is looked up but it is ambiguous whether it should be `N.f` or `M.T.f`. This currently works because renaming for children in export lists is a bit weird and converts the RdrNames to FastStrings and only checks that they are indeed children of the parent without using any of the `lookup*` functions. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11970#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler