Give more helpful comparisons on incorrectly used functions?

[adabe588@…]

It is fairly hard to find errors when you call functions incorrectly, it would be nice to be able to get a unified comparison with more precise info for this. Here's an example of a current error message I got:

Error: No matching function found for AvlTree.foldLeftWith(I.add1, 0, tree)
of type
  .AvlTree.foldLeftWith<function>(foldLeftWithFunction:.I.add1<function>(x:#Integer, el:#Integer) => #Integer, foldAccum:Integer, avlTree:tuple<.I.Compare<function>(x:#Integer, y:#Integer) => Ordering.Ordering, I.Node>) => polymorphic<B> in component <NO COMPONENT>
candidates are 
  .AvlTree.foldLeftWith<function>(foldLeftWithFunction:.Collection.FoldLeftWithFunction<function>(inAccum:polymorphic<FoldAccum>, foldIn:polymorphic<Element>) => polymorphic<FoldAccum>, foldAccum:polymorphic<B>, avlTree:tuple<.AvlTree.Compare<function>(x:polymorphic<A>, y:polymorphic<A>) => Ordering.Ordering, AvlTree.Node>) => polymorphic<B>

Since the candidates are separated from the original call and the candidate types are still generic it is hard to spot the error. It would be nice to get the actual parameter(s) that caused this problem, something along the line of AvlTree.foldLeftWith argument foldAccum cannot unify actual Integer with expected polymorphic<B> if that's where the issue occured.

[Martin Sjölund]

As a first step, rewrite the function matching so that if there is only one candidate, print error-messages for the argument that triggered the error :)

[Martin Sjölund]

Postponed until 1.9.1

[Martin Sjölund]

This ticket was not closed for 1.9.1, which has now been released. It was batch modified for milestone 1.9.2 (but maybe an empty milestone was more appropriate; feel free to change it).

[Martin Sjölund]

Milestone changed to 1.9.3 since 1.9.2 was released.

[Martin Sjölund]

Moved to new milestone 1.9.4

[Martin Sjölund]

Milestone pushed to 1.9.5

[Martin Sjölund]

Milestone renamed

[Martin Sjölund]

Ticket retargeted after milestone closed

[Martin Sjölund]

Milestone moved to 1.12.0 due to 1.11.0 already being released.

[Francesco Casella]

The milestone of this ticket has been reassigned to "Future".

If you think the issue is still valid and relevant for you, please select milestone 1.13.0 for back-end, code generation and run-time issues, or 2.0.0 for front-end issues.

If you are aware that the problem is no longer present, please select the milestone corresponding to the version of OMC you used to check that, and set the status to "worksforme".

In both cases, a short informative comment would be welcome.