Types don't match expressions in type error
Frederik Eaton points out in the thread starting http://www.haskell.org/pipermail/glasgow-haskell-bugs/2007-March/008748.html that with this program:
a x = x True ++ [1]
-- ok
b = a (const [2])
-- uninformative error message
c = a y
-- more informative
d = a ()
y = const ()in the type error, for b the type doesn't match the expression: y has type
a -> () but it claims to have infered () for it:
v.hs:8:6:
Couldn't match expected type `[a]' against inferred type `()'
In the first argument of `a', namely `y'
In the expression: a y
In the definition of `c': c = a y(this example should be made into a testcase once we know what the error will look like).
Trac metadata
| Trac field | Value |
|---|---|
| Version | 6.6 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler (Type checker) |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | Unknown |
| Architecture | Unknown |