Error when accessing index 0 is confusing

[necessarily-equal]

In cases where one tries to access the index of a sequence, no nice error message is printed but the frontend “panics” and prints a generic error message instead:

It could print a nice error message such as “tried to access index 0 of a sequence, in JSONiq indexes start at 1.”
This may affect arrays also, I didn't test that case.

[ghislainfourny]

Thanks @necessarily-equal for this feedback. You are correct that this should not fail with such an error. We will address this.

[mschoeb]

Thanks for the report, turns out it was not just a bad error message but also a bug underneath. The fix for it is now commited in our non-public repo and will be merged sometime in the future