On Friday, May 27, 2016 at 1:38:36 PM UTC-5, David Kraeutmann wrote:
GHCi enables -XExtendedDefaultRules, which cause read "2" to default to ().
Ah - thank you very much! Indeed it is a consequence of the ExtendedDefaultRules option: GHCi, version 7.10.2: http://www.haskell.org/ghc/ :? for help Prelude> :set -XNoExtendedDefaultRules Prelude> read "2" <interactive>:3:1: No instance for (Read a0) arising from a use of ‘it’ On 5/27/2016 8:28 PM, Erik Rantapaa wrote:
Hi fellow Haskellers!
If I bring up ghci and evaluate `read 2` I get the error "Prelude.read: no parse"
GHCi, version 7.10.2: http://www.haskell.org/ghc/ :? for help Prelude> read "2" *** Exception: Prelude.read: no parse
Exactly how is this message coming about? I understand that `read` needs a return type in order to determine which type class instance to run. So, in this case, which type is `read` being asked to return?
Thanks, Erik
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