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Boundedness

hydro_lang::live_collections::boundedness

Trait Boundedness 

Source 
pub trait Boundedness:
    SingletonBound<UnderlyingBound = Self>
    + KeyedSingletonBound<UnderlyingBound = Self>
    + OptionalBound<UnderlyingBound = Self>
    + Sealed {
    type AggregatedOptional: OptionalBound<UnderlyingBound = Self>;
    type PreserveOrderIfBounded<InO: Ordering>: Ordering;

    const BOUNDED: bool;
    const BOUND_KIND: BoundKind = _;
}
Expand description

A marker trait indicating whether a stream’s length is bounded (finite) or unbounded (potentially infinite).

Implementors of this trait use it to signal the boundedness property of a stream.

Required Associated Constants§

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const BOUNDED: bool

true if the bound is Bounded, false if it is Unbounded.

Provided Associated Constants§

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const BOUND_KIND: BoundKind = _

The BoundKind corresponding to this type.

Required Associated Types§

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type AggregatedOptional: OptionalBound<UnderlyingBound = Self>

The OptionalBound of an optional produced by aggregating a stream with this boundedness (e.g. reduce/max/min/first/last).

A Bounded stream yields a Bounded optional. An Unbounded stream yields an InitNone optional: such an aggregation is materialized at a top-level location where its state persists across ticks, so once the first element arrives the result becomes non-null and stays non-null (its value may still change).

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type PreserveOrderIfBounded<InO: Ordering>: Ordering

Determines the output ordering of a join based on this (right/build) side’s boundedness.

When this side is Bounded, the join accumulates this side first and then streams the left side through, preserving the left side’s ordering InO. When this side is Unbounded, a symmetric hash join is used and ordering is lost.

Dyn Compatibility§

This trait is not dyn compatible.

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

Implementors§