Support intersection arrow syntax in playground

[tstirrat15]

Description

Copy and paste this schema in:

definition user {}

definition group {
    relation user: user

    permission view = user
}

definition thing {
    relation group: group

    permission view = group.all(view)
}

See that you get:

Expected end of statement or definition, found: TokenTypePeriod

Note

This is a known issue; we have a beta that we're testing with it now.