#9256: Support automatic derivation of an hs-boot file from an hs file -------------------------------------+------------------------------------ Reporter: ezyang | Owner: ezyang Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.2 Resolution: | Keywords: backpack Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Comment (by ezyang): Replying to [comment:3 goldfire]:
Where is augustss's proposal in #1409? There's ''lots'' of text there.
What is a "mutual recursion breaker"? Is it something that ''does'' appear in the hi-boot file? Or is it something that ''does not'' appear in
Are you proposing that every module, even in the absence of pragmas, now
Your proposal suggests that every top-level definition will now need a type signature, but I don't imagine you mean that. Is this only when some
I quoted his comment, but it's this one: https://ghc.haskell.org/trac/ghc/ticket/1409#comment:13 the hi-boot file? (Sounds like the latter.) Yep, the latter. produce both a hi and a hi-boot file? Hm, that's probably bad. It should only generate an hi-boot file if there is some pragma. pragma is specified? Yep.
Then, not quite understanding what breakers are, my understanding goes downhill from there.
In your summary, is there something that distinguishes a "hs to hs-boot file" from a normal hs file?
Sorry -- this is interesting to me, but I'm a little lost here. Thanks!
So let's be a bit more concrete about the use case. 1. You're writing a pair of modules A and B, and you realize that you want some mutual recursion. 2. In the old world order, you'd pick one module to be loop-breaker (say A), create a boot file (A.hs-boot), and modify B's import to be a SOURCE import. 3. In the new world order, you instead add a pragma to A.hs which specifies which identifies would have been placed in the A.hs-boot file. B still receives a SOURCE import as before. 4. Now, when performing `--make` compilation, we notice that A.hs has a pragma, so we pretend as if an hs-boot file existed, and first compile A.hs as a boot file, then compiling B.hs and then A.hs normally. I haven't worked out how to adjust one-shot compilation to work with this. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9256#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler