proposal: Better way of handling nil maps

[guettli]

Proposal Details

For slices, the handling of nil is easy:

s = append(s, foo)

Above code works fine if s is nil.

But for maps, this does not work.

Checking if a map is nil, and if it is, doing make(...) is not convenient.

I propose to extend append() to maps:

m = append(m, key, value)

Above should work, even if m is nil.

I am looking to a solution to the overall goal (Better way of handling nil maps).

Maybe there is a better syntax to do that....

What alternatives to m = append(m, key, value) do you suggest?

[gabyhelp]

Related Issues and Documentation

• proposal: extend the "append" built-in to work with maps #17350 (closed)
• proposal: runtime: mapaccess shouldn’t panic on nil map #29631 (closed)

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[seankhliao]

Duplicate of #17350

[guettli]

The duplicate is eight years old. Maybe it’s time to think about this again? Why not make Go more newbie-friendly?

[seankhliao]

While the previous issue is old, the points discussed there still hold. Without significant new information, a rehash of a previous discussion is just going to end up with the same decision.