test_rows¶
Naming an arm’s rows: offsets always, values only when someone reads them.
Functions¶
The source a split between two engines that each hold the data wants: |
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Relative indices in, absolute offsets out: the offset is the number an |
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Refuse rather than approximate, and refuse rather than materialize the |
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An arm written against a row iterator would otherwise see no rows and |
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It lands in the refusal message above, and a six-million-row repr is |
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A caller who already has the rows pays nothing to hand them over -- |
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A degenerate share hands one arm everything; copying the caller's |
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Python slicing would clamp or wrap these; a boundary that arithmetic |
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Module Contents¶
- test_rows.test_a_range_is_two_integers_at_any_row_count() None¶
The source a split between two engines that each hold the data wants: six million rows and not one of them exists.
- test_rows.test_a_slice_carries_absolute_offsets() None¶
Relative indices in, absolute offsets out: the offset is the number an arm slices its own resident copy at, so it has to name the whole table.
- test_rows.test_a_range_refuses_the_arm_that_reads_values() None¶
Refuse rather than approximate, and refuse rather than materialize the table behind the caller’s back to keep an arm fed.
- test_rows.test_iterating_a_range_reaches_the_same_refusal() None¶
An arm written against a row iterator would otherwise see no rows and return a confident empty answer.
- test_rows.test_a_range_cannot_be_inverted() None¶
- test_rows.test_a_batch_repr_does_not_print_the_table() None¶
It lands in the refusal message above, and a six-million-row repr is not a message.
- test_rows.test_a_sequence_is_wrapped_in_place() None¶
A caller who already has the rows pays nothing to hand them over – identity is what pins that, because a copy compares equal and fails only
is.
- test_rows.test_a_whole_table_slice_does_not_copy() None¶
A degenerate share hands one arm everything; copying the caller’s sequence to say so is the same cost in miniature.
- test_rows.test_an_iterator_is_drained_because_it_cannot_serve_two_arms() None¶
- test_rows.test_a_sub_range_must_lie_inside_its_parent(bounds) None¶
Python slicing would clamp or wrap these; a boundary that arithmetic got wrong must refuse rather than hand an arm a different row set.
- test_rows.test_a_sub_range_may_be_empty_or_the_whole_parent() None¶
- test_rows.test_a_row_batch_refuses_a_negative_start() None¶