New implementation of dict.update

[inoas]

Replaces #610

[inoas]

I think this function should be called change.

I think the other implementation already done should be called update https://github.com/gleam-lang/stdlib/pull/610/files.

Update means that there already is something and it can fail to update. Update does not signal removal. Change signals removal. Change fits to this PR, update to the other.

[lpil]

Thank you

[inoas]

@lpil are you certain about this being named update rather than change?

[lpil]

What's the motivation for it being change. I thought we did the whole deprecation cycle to free up the name update?

[inoas]

What's the motivation for it being change. I thought we did the whole deprecation cycle to free up the name update?

1. update could be used for this impl if so desired https://github.com/gleam-lang/stdlib/pull/610/files#diff-8630634f9cc0ec3abcfa5aea55f3be0e549a2131a5cce9b7f551f880ceaaaac4R497-R502

2. More importantly, the word update signifies that a key-pair value should exist and is updated, but the impl in this PR here may insert even if there is no key or remove if there is a key (see the test suite in this PR for examples), all depending on the change function/callback.

   It changes the dict based on the function, so IMHO change is much clearer, whereas if I read dict.update I would not assume that afterwads a key-value pair is potentially removed from the dict (or added if not existing prior).

[inoas]

Because other functions usually return Result rather than Option, I have opted for the change function to return Result not Option as well.

I have added a unit test example to show what I mean.

Are you certain you want to return Option instead?

ref #659 (comment) cc @lpil

[inoas]

After feedback I made the changes to return Option rather than Result and tried to simplify the docs and the unit tests

[inoas]

This is still ready to be reviewed/merged unless you want me to rename this to change and have update do the other impl (see above). Please let me know if there are still things to do.

[inoas]

Any chance to get this into 0.42 with either name change or name update, it has been ready for a few month now @lpil

[inoas]

I have removed conflicts with recent changes on main branch

@lpil any news on this PR?

I am hoping for one of these:

• merge as is
• rename from update to change (my vote)
• discard PR

[inoas]

I have resolved the merge conflicts another time.

Is this desired (as update() or as change())?

[lpil]

Hello! Thank you for this but I've not yet had any reports of real applications feeling they need this yet so I would like to wait until that demand is clear.

[inoas]

Hello! Thank you for this but I've not yet had any reports of real applications feeling they need this yet so I would like to wait until that demand is clear.

OK, someone in future can implement it as change() (or update()) if demand is noticed.