Immutable vnodes

[buntec]

Experiments in making vnodes immutable.

[buntec]

This is currently broken despite all tests passing. Yikes!

[buntec]

Looks better now, though the fact that the tests didn't catch these issues is disconcerting!

[buntec]

Tests are passing and some ff4s examples look ok, too. The biggest concern is probably performance, although the todo-mvc benchmark using ff4s barely budged after the change. Not sure what to make of that.

[armanbilge]

though the fact that the tests didn't catch these issues is disconcerting!

This would be my concern, would be nice to add some tests for these.

Unfortunately I don't think I can do an in-depth review of this one, but if it works it works :) 👍

[buntec]

though the fact that the tests didn't catch these issues is disconcerting!

This would be my concern, would be nice to add some tests for these.

Unfortunately I don't think I can do an in-depth review of this one, but if it works it works :) 👍

No worries! I'm aware that this is a big change, and one that marks a clear departure from the original snabbdom. Any high level feedback would still be appreciated ;). Having immutable vnodes is one of the things mentioned by @cornerman in this issue.

I'll try to increase test coverage to include the cases I came across when making these changes.