Orientation of given `Coercible` constraints
Prelude> :m + GHC.Exts
Prelude GHC.Exts> let f :: Coercible a b => b -> a ; f = coerce
<interactive>:3:40:
Could not coerce from ‛b’ to ‛a’
because ‛b’ and ‛a’ are different types.
arising from a use of ‛coerce’
from the context (Coercible a b)
bound by the type signature for f :: Coercible a b => b -> a
at <interactive>:3:10-32
In the expression: coerce
In an equation for ‛f’: f = coerce
Something better could be done here (but its not clear what exactly, and to what general extend).
Trac metadata
Trac field | Value |
---|---|
Version | 7.6.3 |
Type | FeatureRequest |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler (Type checker) |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |