On 11/6/05, Klaus Ostermann <[EMAIL PROTECTED]> wrote:
At this point, isConnectedTo knows nothing about the third argument except that it is an edge, and there's no reason to think that an Edge is a tuple. All you can say is that there are two functions, n1 and n2, which extract the nodes of the edge. Use those instead, for example
isConnectedTo g n p = n == n1 p || n == n2 p
Hopefully this error makes more sense now. It's saying that it expected something of type 'e', but it found a tuple.
regards,
instance Node Person where
isConnectedTo g n (p1,p2) = (p1 == n) || (p2 == n)
At this point, isConnectedTo knows nothing about the third argument except that it is an edge, and there's no reason to think that an Edge is a tuple. All you can say is that there are two functions, n1 and n2, which extract the nodes of the edge. Use those instead, for example
isConnectedTo g n p = n == n1 p || n == n2 p
Couldn't match the rigid variable `e' against `(a, b)'
`e' is bound by the type signature for `isConnectedTo'
Expected type: e
Inferred type: (a, b)
When checking the pattern: (p1, p2)
In the definition of `isConnectedTo':
isConnectedTo g n (p1, p2) = (p1 == n) || (p2 == n)
Hopefully this error makes more sense now. It's saying that it expected something of type 'e', but it found a tuple.
Fraser.
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