WEBVTT

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This overview explains when eager and lazy paths
perform the work required by a completed request.

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Deferring an operation can reduce unnecessary work,
but it cannot erase work the requested output still needs.

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Deferring an operation can reduce unnecessary work,
but it cannot erase work the requested output still needs.

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Suppose a caller requests the complete vector for A and B.

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The required output is zero zero zero one in the declared order.

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The comparison must end with those four bits available to the caller, regardless of how

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the method schedules its work.

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An eager path computes and stores the vector immediately.

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Its constructor or preparation step may therefore look expensive because it has already

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performed work that the caller ultimately needs.

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The timing boundary must make that work visible.

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A deferred path initially stores an operation describing the vector.

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This may be quick, but the four output bits have not yet been delivered.

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When the caller asks to read the vector, the pending work must run.

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Compare both paths through that materialization step.

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Compare both paths through that materialization step.

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Eager construction performs aligned array
work while building its representation.

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A lazy path defers work until the requested result needs materialization.

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The two timelines compare identical inputs and the same required output.

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Here, the four-input example requires all 16 truth outputs.

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The eager path performs construction and aligned
array work before the request completes.

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The lazy path first retains a deferred structure, then materializes
the full array when the complete output is requested.

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Both finished grids must agree at every
address, including 1011 with output one.

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A deferred cost has moved, not vanished.

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If a task never requests a full array, its
obligations differ from the task that does.

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Time preparation, request execution and

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extraction explicitly rather than crediting a lazy
path for leaving a required step unfinished.

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Return to the opening two-input rule F equals A and B.

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This is separate from the intervening four-input contract.

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The complete two-input vector is zero zero zero one.

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If this object is never read, deferred calculation can avoid work.

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We will next change the caller to a point query.

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If the caller only needs input one zero, a point evaluator can compute zero without delivering the whole vector.

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This is a legitimate task change, but a point answer cannot be reported as completion of the earlier full-vector request.

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Repeated full reads can favor retaining materialized data after the first read.

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The useful boundary depends on the object's lifetime and whether later reads actually reuse it.

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Deferred and eager describe scheduling choices; they are not permanent speed rankings.

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Deferred and eager describe scheduling choices; they are not permanent speed rankings.

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Compare the same delivered result.

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Include deferred materialization, extraction,
and preparation where the lifecycle requires them.