Enum FilterKind 

pub enum FilterKind {
    Opaque,
    Range {
        bounds: Box<dyn Fn(&[&dyn Any]) -> Option<(Box<dyn Any>, Box<dyn Any>)>>,
    },
}

What shape of validation/derivation a Filter performs, beyond its opaque function — set by adam-lang’s compile phase when a filter’s expression matches a recognized structural form. Opaque carries no extra information; consumers that don’t care about structure treat every kind identically at write/propagate time — FilterKind is purely informational, queried by consumers like begin’s UI that want to render a specialized editor without inspecting the filter’s function.

Variants

Opaque

The filter’s expression wasn’t a recognized structural form.

Range

Compiled from a RangeInclusive<T>-typed expression (lo..=hi). bounds re-evaluates that expression against the filter’s current argument values, returning the resulting (lo, hi) as type-erased values of the filtered cell’s own type T, or None if the underlying expression fails to evaluate (e.g. a fallible arithmetic op in a range endpoint, such as a checked_* operation overflowing). The bound evaluator satisfies Filter’s purity and invocation contract.

Fields

bounds: Box<dyn Fn(&[&dyn Any]) -> Option<(Box<dyn Any>, Box<dyn Any>)>>

Re-evaluates the range expression, returning (lo, hi) as type-erased values, or None if evaluation fails.

Adam-compiled evaluators also return None for missing or extra arguments, incorrect scalar identities, or mismatched compound carriers or shapes. They validate every argument before binding raw addresses or evaluating, including on calls following a successful evaluation or rejection.