#9207: Detect obvious cases of infinite recursion. -------------------------------------+------------------------------------- Reporter: mrugiero | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.4.4 Resolution: | Keywords: infinite | recursion 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 svenpanne): OK, let's forget about the warning caused by not using `loadImg` for a moment. Why should a compiler warn about the body of `loadImage`? I seriously hope that it doesn't warn, because `liftIO` is a method of the `MonadIO` type class, so the compiler has no knowledge whatsoever about it, apart from its type. So passing `loadImage fpath` to it might actually make sense, see the `repeat` example above. If you are lucky and the compiler uses enough optimizations, you might get a warning at `loadImage`'s use sites, because then it might see enough context, but the function alone is perfectly OK from a compiler's point of view. In a lazy language, it's quite hard to distinguish between "wanted infinite recursion" and "unwanted infinite recursion". -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9207#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler