[docs] Dynamic fields example has errors

[SteVwonder]

What version of CUE are you using (cue version)?

❯ cue version
cue version v0.6.0

What did you do?

I copied the dynamic fields example from the docs at https://cuelang.org/docs/references/spec/#dynamic-fields

sherbein ~/scratchspace/cue-dynamic-fields
❯ cat test.cue                     
package test

a:   "foo"
b:   "bar"
(a): "baz"

(a+b): "qux"

(a)?: string
(b)!: string

What did you expect to see?

What is listed in the docs :

a:   "foo"
b:   "bar"
bar: "baz"

foobar: "qux"

foo?: string
bar!: string

What did you see instead?

sherbein ~/scratchspace/cue-dynamic-fields
❯ cue eval                         
a:      "foo"
b:      "bar"
foo:    "baz"

foobar: "qux"

bar!:   string

The output from the command is definitely correct and the mistake lies with the docs. Basically the docs should be updated so that the result of (a): "baz" is foo: "baz" not bar: "baz". The a: "foo in the docs example also needs a closing ".

I'm happy to post a PR once I confirm employer sign-off on contributions.

[mvdan]

Please do send a patch :) This looks wrong indeed. I also see a: "foo rather than a: "foo", a closing double quote is missing.