readline: use logical assignment operators

[VoltrexKeyva]

With the addition of the new logical assignment operators
(||=, ??= and &&=), we could use them here.

[VoltrexKeyva]

On a note, if these changes are alright; could we change this PR to make use of the operators in all the lib modules instead of just this one? Or should we make several different PRs for it?

[aduh95]

After what we learned in #38245, I think we should be extra cautious when making this kind of change to existing code. The risk of introducing perf regressions for the sake of a small (debatable) improvement in the readability of code seems like a pretty bad deal IMHO, I would be -1 for anything that touches a hot code path (in the case of readline, I'm -0).

I don't think we should land this kind of change until:

1. perf concerns have been addressed by V8.
2. there's a lint rule to enforce it.

could we change this PR to make use of the operators in all the lib modules instead of just this one? Or should we make several different PRs for it?

Keeping the PRs minimal would be the right way to go: it's easier to review, has less risk of getting conflicts with other PRs, and easier to revert.

[VoltrexKeyva]

After what we learned in #38245, I think we should be extra cautious when making this kind of change to existing code. The risk of introducing perf regressions for the sake of a small (debatable) improvement in the readability of code seems like a pretty bad deal IMHO, I would be -1 for anything that touches a hot code path (in the case of readline, I'm -0).

I don't think we should land this kind of change until:

1. perf concerns have been addressed by V8.
2. there's a lint rule to enforce it.

could we change this PR to make use of the operators in all the lib modules instead of just this one? Or should we make several different PRs for it?

Keeping the PRs minimal would be the right way to go: it's easier to review, has less risk of getting conflicts with other PRs, and easier to revert.

Understandable, I don't think its worth it to land a small change like this that probably has a chance of either causing a perf regression or something similar until the rules you mentioned such as them being addressed by V8; closing.