ResourceIdentifier.metadata Map and List

[dcharkes]

Allowed types are bool, int, double, and String.

https://pub.dev/documentation/meta/latest/meta/ResourceIdentifier/metadata.html

For dart-lang/native#1085, we need support for maps. (Which was discussed in https://dart-review.googlesource.com/c/sdk/+/355922, but not yet implemented.)

[lrhn]

Consider just allowing any JSON-shaped data. I expect that the maps you need are all string keyed.
(The documentation should probably also say that it allows null.)

How is the data "made available to post-compile steps"?
Do they have access to the source, or to a textual representation of the value?
If is textual, might as well but the bullet and allow full JSON, so people don't have to write it in a string.

[dcharkes]

JSON-shaped data makes sense. 👍

So we'd exclude support for:

• Sets
• Tuples
• Instance constants
• Maps with keys other than strings.

We could add support for those if we come up with some kind of encoding scheme, but so far I have not seen any use cases for non-JSON shaped data.

[dcharkes]

If we support multiple fields in subtypes of ResourceIdentifier (#55568), then we might not have a need to support maps.