#14084: Strange behavior of GHC by writing the types in GHCi -------------------------------------+------------------------------------- Reporter: vanto | Owner: (none) Type: bug | Status: closed Priority: normal | Milestone: Component: GHCi | Version: 8.0.2 Resolution: invalid | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect result | Unknown/Multiple at runtime | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by hsyl20): @vanto
It can with numbers but it can not with characters.
It seems like you don't understand the type of numeric literals in Haskell. Please read https://www.haskell.org/onlinereport/basic.html#sect6.4.1 Then this will make sense: {{{#!hs
:t (:) (:) :: a -> [a] -> [a] :t 1 1 :: Num t => t :t (1:) (1:) :: Num a => [a] -> [a] :t (1:2) (1:2) :: (Num [a], Num a) => [a] }}}
The ML and Miranda compilers, for example, do not manage to evaluate this kind of poorly written list, as well as with numbers or characters.
Probably because they aren't compilers for the same language. AFAIK ML compilers don't allow `1` to be used as a Float literal, we have to use `1.` instead. Different trade offs... -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14084#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler