Replying to [comment:5 nomeata]:
In fact, what I do not like about {{{ ghci> minimumBy compare [] *** Exception: Prelude.foldr1: empty list CallStack: error, called at libraries/base/GHC/List.hs:999:3 in
}}} is that it leaks implementation details. This is great in your own code, but a polished library should _not_ leak a call stack about its
#11035: Add implicit call-stacks to partial functions in base -------------------------------------+------------------------------------- Reporter: gridaphobe | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 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 gridaphobe): Replying to [comment:10 goldfire]: base-4.8.2.0:GHC.List details; it should either print plain exception or the call stack that finishes at the library’s API. At least for “expected exceptions” like `"empty list"`.
I disagree with this push toward perfection. I understand what you're
getting at here, and I agree in principle. But I think this issue (which does seem to be independent from the original ticket) is not terribly important to solve. In other languages, I've seen standard libraries spill their implementation details all over the place in stack traces. I'm generally inclined to agree that there's no harm in spilling implementation details in the stack trace, I can't think of a single language that lets you do what Joachim is suggesting. That being said, it sounds like it could be a very lightweight extension of the existing machinery, so it might be interesting to experiment with. But it probably should be a separate ticket :) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11035#comment:14 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler