[GHC] #7727: Nonsense evaluation: sequence [] = []

GHC cvs-ghc at haskell.org
Thu Feb 28 01:16:04 CET 2013


#7727: Nonsense evaluation: sequence [] = []
-----------------------------+----------------------------------------------
Reporter:  drb226            |          Owner:                  
    Type:  bug               |         Status:  new             
Priority:  normal            |      Component:  Compiler        
 Version:  7.6.2             |       Keywords:                  
      Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple
 Failure:  None/Unknown      |      Blockedby:                  
Blocking:                    |        Related:                  
-----------------------------+----------------------------------------------
 {{{
 $ ghci-7.6.2
 GHCi, version 7.6.2: http://www.haskell.org/ghc/  :? for help
 Loading package ghc-prim ... linking ... done.
 Loading package integer-gmp ... linking ... done.
 Loading package base ... linking ... done.
 >>> sequence []
 []
 >>> :t it
 it :: [()]
 >>> sequence [] :: [()]

 <interactive>:4:1:
     Couldn't match type `[a0]' with `()'
     Expected type: [()]
       Actual type: [[a0]]
     In the return type of a call of `sequence'
     In the expression: sequence [] :: [()]
     In an equation for `it': it = sequence [] :: [()]

 }}}


 Wat. Where on earth did ghci get the idea that {{{ sequence [] = [] }}}?

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7727>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler



More information about the ghc-tickets mailing list