Trait MissingPolicy 

pub trait MissingPolicy<A: Alignment, S: SourceDomain>:
    Send
    + Sync
    + Clone
    + 'static
    + Explain
    + PlanIdentity
    + PlanInputs {
    type Retention: Retention;
    type Prepared<'a>: Clone + 'a
       where Self: 'a;

    // Required methods
    fn prepare<'a>(
        &'a self,
        graphrecord: &'a GraphRecord,
        cache: &'a EvaluationCache<'a>,
    ) -> QueryResult<Self::Prepared<'a>>;
    fn resolve_absent<'a>(
        prepared: &Self::Prepared<'a>,
        address: &A::Address<'a>,
        label: &'static str,
    ) -> <Self::Retention as ElementEmission>::Step<QueryResult<<S::ValueDomain as ValueDomain>::Value<'a>>>
       where S: 'a;
}

Required Associated Types

type Retention: Retention

type Prepared<'a>: Clone + 'a where Self: 'a

Required Methods

fn prepare<'a>( &'a self, graphrecord: &'a GraphRecord, cache: &'a EvaluationCache<'a>, ) -> QueryResult<Self::Prepared<'a>>

fn resolve_absent<'a>( prepared: &Self::Prepared<'a>, address: &A::Address<'a>, label: &'static str, ) -> <Self::Retention as ElementEmission>::Step<QueryResult<<S::ValueDomain as ValueDomain>::Value<'a>>>

where S: 'a,

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl<A, S, R> MissingPolicy<A, S> for Replace<R>

where A: Alignment, S: SourceDomain, R: ArgumentSource<A, S::ValueDomain> + Clone,

type Prepared<'a> = <R as Prepare>::Prepared<'a>

type Retention = <R as ArgumentSource<A, <S as SourceDomain>::ValueDomain>>::Retention

impl<A: Alignment, S: SourceDomain> MissingPolicy<A, S> for Drop

type Prepared<'a> = ()

type Retention = Dropping