How can I tell pest.rs to flatten grammar?

Question

Let's say I have a rule like,

key = { ASCII_ALPHA ~ ( ASCII_ALPHA | "_" )+ }
value = { (!NEWLINE ~ ANY)+ }
keyvalue = { key ~ "=" ~ value?  }
option = { key }

This supports a

K=V
K=
K

Which is want to set/unset a key, and to specify an option, what I don't like is the syntax for option which produces an AST like this,

rule: option,
span: Span {
    str: "check_local_user",
    start: 302,
    end: 318,
},
inner: [
    Pair {
        rule: key,
        span: Span {
            str: "check_local_user",
            start: 302,
            end: 318,
        },
        inner: [],
    },
],

I don't like that my option has inner with key. I'm just wanting to the option to have the same grammar as a key. Is there any method in Pest.rs to write the grammar such that

inner { myStuff }
outer = { inner }

gets flattened to

outer = { myStuff }

Answer 1

Using the Atomic Parsing Token @, I could accomplish this.

option = @{ key }

It's documented as,

Any rules called by atomic rules do not generate token pairs.