Function application signature help - improvements list

[cartermp]

This tracks improvements to the signature help feature for function applications.

• Tooltip disappears when typing out arguments in a function application

This one is tricky with the current implementation. We can either:

• Keep the tooltip up when typing out arguments to a function application
• Keep the tooltip up when typing out arguments in a method call

The latter has always worked, so it's currently implemented to do that. But it'll be more work to figure out how to do both.

• Still triggers unexpectedly inside of a parenthesized context

As of #10954 this should be improved a lot, since it covers parenthesized contexts that have a lambda. But it can still trigger in cases like this:

To address this, we'll need to figure out a way to generalize the parenthesized case for TryRangeOfFunctionOrMethodBeingApplied.

[cartermp]

For the general parenthesized case, it may be enough to get away with just two more matches; one on SynExpr.Parent(SynExpr.Paren(... and another on SynExpr.Paren(SynExpr.Tuple(.... I'll see if that feel sufficient or not.

[cartermp]

closing out for now