Struct OnlyRule 

pub struct OnlyRule {
    pub from: String,
    pub to: Vec<String>,
    pub raw: String,
}

⟨0.29⟩ One only <A> -> <B> [<C> …] PERMISSION rule (AS-EFF-011): a function in scope A may reach A itself and the listed scopes, and NOTHING else.

forbid FAILS OPEN; only FAILS SAFE, and that is the whole reason the form exists. A dependency you forgot to prohibit is silently permitted, so “this package is a leaf” can only be spelled by enumerating what it must not reach — a list that does not cover a package added later, and nothing says so. That is the allowlist hazard this project refuses everywhere in the analysis, living in the POLICY LANGUAGE instead. Under only, a dependency you forgot to permit is a loud violation.

Found by pointing candor’s own architecture gate at candor: the natural forbid io.poly.candor.model -> io.poly.candor SELF-FIRES at 58 violations, because a scope matches a contiguous run of segments and model sits under the very prefix it is trying to protect itself from.

THE WALK STOPS AT A PERMITTED SCOPE, and that is a semantic decision rather than an optimisation: a permitted callee’s own dependencies are governed by the rules about IT, not by this one. Descending past it would make only require the transitive closure of everything you permit — which is the enumeration-that-rots this form exists to replace, one level down.

Fields

from: String

The scope being constrained. It may always reach ITSELF: an explicit A -> A would be noise, and without the implicit permission the form is unusable for exactly the case it exists for.

to: Vec<String>

The scopes from may reach. At least one — only A -> with nothing after the arrow is DROPPED as malformed rather than read as “A may reach nothing at all”, which is a different rule (and one a reader is far more likely to have typed by accident than to have meant).

raw: String

Trait Implementations

impl Clone for OnlyRule

fn clone(&self) -> OnlyRule

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for OnlyRule

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.