At 12:12 PM -0700 9/13/02, Richard Barth wrote:
I'm just learning Haskell with Hugs98. I can't understand why the line defining "foo" is acceptable while the line defining "bar" (only difference is the unary minus) generates the error message at the end. If someone could explain this, or, better yet, tell me how I can figure this out for myself. Thanks.
data Entry = Ent {date :: String, amount :: Double}
foo = [Ent "baz" 1.0]
bar = [Ent "baz" -1.0]
Type checking......
ERROR "...test.hs":7 - Unresolved top-level overloading
*** Binding : bar
*** Outstanding context : Fractional (Double -> Entry)
Recall that function application has a higher priority than all the operators --including unary (-). --Ham -- ------------------------------------------------------------------ Hamilton Richards Department of Computer Sciences Senior Lecturer The University of Texas at Austin 512-471-9525 1 University Station C0500 Taylor Hall 5.138 Austin, Texas 78712-1188 ham@cs.utexas.edu hrichrds@swbell.net ------------------------------------------------------------------