array::at() method returns INDEX_OUT_OF_BOUNDS

[ksandro]

array::at() method returns INDEX_OUT_OF_BOUNDS

[lemire]

Do you refer to this function in our On Demand API?

  /**
   * Get the value at the given index. This function has linear-time complexity.
   * This function should only be called once on an array instance.
   */
  simdjson_inline simdjson_result<value> at(size_t index) noexcept;

You have taken into account that you should call once on an array instance?

This function is very specialized, it is meant to be used only when you need just one entry. We deliberately disallow repeated calls to it.

It is stated explicitly in our main documentation:

Maybe you mean to use our DOM API?

https://github.com/simdjson/simdjson/blob/master/doc/dom.md

[lemire]

I removed the bug label since the provided code sample violates the function specification.

[lemire]

The code sample uses count_elements(), please refer to the documentation on its usage:

Users should be aware that the count_elements method can be costly since it requires scanning the whole array. You should only call count_elements as a last resort as it may require scanning the document twice or more.

[ksandro]

Ok, now I see that it is really mentioned in the documentation. Sorry, I missed it.
But it is non intuitive, that this function can not be called two times, and in some cases it works. If I call at(0) than at(1) gives correct result in my example. Maybe it is possible somehow to forbid incorrect usage, but it is not important I think the issue can be closed.

I used count_elements() just for debugging, to be sure that array really contains required number of elements, it is not used in production code.

[lemire]

Closing.

Pull requests are always invited.