#14551: GHCi ignores -XMonomorphismRestriction and -XNoExtendedDefaultRules -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: GHCi | Version: 8.2.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Other | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Description changed by dfeuer: Old description:
Because of the way the GHCi defaults are applied, specifying `-XMonomorphismRestriction` or `-XNoExtendedDefaultRules` on the GHCi command line doesn't actually make those take effect at the interactive prompt. They get reset to their interactive defaults afterwards. This is rather surprising, and I think it should be fixed.
One option is to dig through the parsed flags after setting the defaults to try to find these, but that sounds unpleasant. We're slowly accumulating hacks in this area, and it would be nice to find a better approach.
New description: Because of the way the GHCi defaults are applied, specifying `-XMonomorphismRestriction` or `-XNoExtendedDefaultRules` on the GHCi command line doesn't actually make those take effect at the interactive prompt. They get reset to their interactive defaults afterwards. This is rather surprising, and I think it should be fixed. {{{ dfeuer@squirrel> ghci -XMonomorphismRestriction Prelude> x = 3 Prelude> :t x x :: Num t => t -- What? I said I wanted the restriction! Prelude> :set -XMonomorphismRestriction Prelude> y = 3 Prelude> :t y y :: Integer }}} One option is to dig through the parsed flags after setting the defaults to try to find these, but that sounds unpleasant. We're slowly accumulating hacks in this area, and it would be nice to find a better approach. -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14551#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler