Are you submitting a bug report or a feature request?

bug report

What is the current behavior?

toPath splits 'foo["bar.baz"]' to ['foo', '"bar', 'baz"']

It's impossible to use a nested object key with . in the name and messy to use a nested object key that's not a valid JS identifier. 'foo["bar.baz"]' is an idiomatic JS pathstring supported by libs like lodash.get:

_.get({foo: {"bar.baz": 3}}, 'foo["bar.baz"]') // 3

I have to use an arbitrary, user-entered string value as part of the nested object key, so I need final-form to support quoting and escaping properly here.

My field name that was working fine in redux-form and is now broken with final-form is "Channels["{\"type\":\"MetadataItem\",\"connectionId\":14,\"direction\":\"FROM_GATEWAY\",\"tag\":\"mqttChannel1\"}"].internalTag".
mqttChannel1 is the user-entered value, and I'm using JSON.stringify to safely escape the object that forms this key.

What is the expected behavior?

toPath splits 'foo["bar.baz"]' to ['foo', 'bar.baz']

What's your environment?

not relevant