Functions such as array:put, array:replace, array:insert-before, array:head, array:tail continue to perform bound checking.

To improve symmetry with sequences, I think we should get rid of the checks for all read function, including array:head and array:tail, to ensure that expressions like $array(1) and array:head($array) can be mutually rewritten (both by users and optimizers). But I agree it’s a good idea to keep the checks for updates.

In discussion on 2025-02-18, there were considerable reservations about the backwards compatibility impact.

One proposal that may be sufficient to get the proposal through is to add an option in the static context to control this.

Other suggestions were about doing this as an option on individual operations (which we have already tried with array:get) or as a property of the array itself. My own feeling is that such options would be too intrusive.

Marking the PR as blocked awaiting revision.

I have read the meeting summary (thanks, @ndw).

I wonder which other cases exist, apart from try/catch clauses, in which backwards compatibility would be an issue? If it’s only try/catch, I am sure we will have other 4.0 changes that are much more consequential (first of all, the disallowance of keywords for names in node constructors).