#14161: Performance Problems on AST Dump -------------------------------------+------------------------------------- Reporter: h4ck3rm1k3 | Owner: dfeuer Type: bug | Status: new Priority: low | Milestone: 8.2.2 Component: Compiler | Version: 8.3 Resolution: | Keywords: Operating System: Linux | Architecture: x86_64 Type of failure: Compile-time | (amd64) performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by dfeuer): Actually, that's only one piece of the puzzle. Another major problem is that when `showAstData` is called in `HscMain`, its (`String`) result is converted to an `SDoc` using `text`. In order to even think about rendering that result, `Pretty` calculates its length. This forces the entire dump to be built in memory as a `String`. I don't have enough memory to do that on my system! I'm working on a patch to make `showAstData` produce a `Doc` right from the start rather than a `String`. Initial experiments suggest that this has a much better chance of working. One question: when should one produce a `Doc` and when should one produce an `SDoc`? I'm pretty unclear on that bit. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14161#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler