Deriving Data does not work for attached code
For attached code I get this error:
Test2.hs:19:48:
Could not deduce (Real r, Random r)
from the context (Data r, Typeable1 t)
arising from a use of `f'
Possible fix:
add (Real r, Random r) to the context of
the type signature for `dataCast1'
or the instance declaration
In the first argument of `gcast1', namely `f'
In the expression: gcast1 f
In an equation for `dataCast1': dataCast1 f = gcast1 f
Trac metadata
Trac field | Value |
---|---|
Version | 7.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler (Type checker) |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | mmitar@gmail.com |
Operating system | |
Architecture |