Hi David, it looks like Rustom's aware that haskell's not lisp. What he
really wants methinks is a way to suppress type classes altogether! That or
a NoOverloadedNumerals extension.
-- Kim-Ee
On Thu, Dec 27, 2012 at 4:03 PM, David Virebayre wrote: Prelude> :t [[1,2],3] you have a list with 2 elements:
- [1,2]
- 3
the type of [1,2] is [Integer]
the type of 3 is Integer But all elements in a list must have the same type. 2012/12/27 Rustom Mody On Thu, Dec 27, 2012 at 1:48 AM, Roman Cheplyaka * Rustom Mody So is there any set of flags to make haskell literals less wrote:
polymorphic? Yes, there is! % ghci -XRebindableSyntax
GHCi, version 7.6.1: http://www.haskell.org/ghc/ :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done. import Prelude hiding (fromInteger)
Prelude> let fromInteger = id
Prelude> :t 3
3 :: Integer Roman Thanks Roman -- that helps.
And yet the ghci error is much more obscure than the gofer error: --- contents of .ghci ---
:set -XRebindableSyntax
let fromInteger = id
------ ghci session -----
$ ghci
GHCi, version 7.4.1: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Prelude> :t 5
5 :: Integer
Prelude> :t [[1,2],3] <interactive>:1:8:
Couldn't match expected type `[Integer]' with actual type `Integer'
Expected type: Integer -> [Integer]
Actual type: Integer -> Integer
In the expression: 3
In the expression: [[1, 2], 3] ----- The same in gofer -----
Gofer session for:
pustd.pre
? :t [[1,2],3] ERROR: Type error in list
*** expression : [[1,2],3] *** term : 3
*** type : Int
*** does not match : [Int]
--------------
So the error is occurring at the point of the fromInteger (= id) but the
message does not indicate that --
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