#13054: Generating unique names with template haskell -------------------------------------+------------------------------------- Reporter: tim-m89 | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Template Haskell | Version: 8.0.1 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 RyanGlScott): I also agree that `newName`s should not be exportable! Moreover, I don't think you really should be exporting `newGlobalName`s either—but that doesn't mean it's a non-use-case! Quite often in Template Haskell code you'll want to define top-level functions that are used across other functions. For example, in my [http://hackage.haskell.org/package /deriving-compat-0.3.6/docs/Data-Enum-Deriving.html deriving-compat] library, I've found myself wanting to define a function: {{{#!hs con2tagFoo :: Foo -> Int# }}} Like what happens when you derive `Enum` in GHC today, only in Template Haskell. This needs to be a top-level identifier, however, since `con2tag` functions also get used across multiple `Enum` methods, so I need to ensure that this `con2TagFoo` name is globally unique. However, it certainly doesn't need to be exported. Currently, the only way to do this is with something like `newUniqueName` from comment:2, which isn't robust against things like infix names. I imagine tim-m89's use case would also be served by `newGlobalName`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13054#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler