#16406: Array code works with GHC 8.4.4, hangs with GHC 8.6.4 -------------------------------------+------------------------------------- Reporter: arybczak | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: libraries | Version: 8.6.4 (other) | Resolution: | Keywords: array 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 bgamari): The report has this to say about accumArray:
If the accumulating function is strict, then accumArray is strict in the values, as well as the indices, in the association list. Thus, unlike ordinary arrays built with array, accumulated arrays should not in general be recursive.
It does sound like we are within our rights to be strict here. However, perhaps we should document this strictness a bit better -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16406#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler