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Module bitmask_view

minarrow::structs::views

Module bitmask_view 

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§BitmaskV Module - Windowed View over an Bitmask

BitmaskV is a logical, zero-copy, read-only window into a contiguous region of a Bitmask.

§Purpose

  • Indexable and bounds-checked access to a subset of a bit-packed mask.
  • All logical indices are relative to the window.
  • Avoids copying - borrows the parent mask by reference.

§Behaviour

  • All operations remap indices internally to the correct positions in the parent mask.
  • Window slicing (slice) is O(1) - pointer and metadata updates only.
  • Uses a lifetime which can be elided in many engine cases. However, if one needs to copy it from there it is a deep clone. Given the backing buffer is a bitpacked u8, this is a materially smaller penalty compared to other Minarrow buffers. This design avoids otherwise threading Arc<Bitmask> through every strongly typed array variant which penalises the default case disproportionately.
  • Use to_bitmask for a materialised copy of the view.

§Threading

  • Thread-safe by virtue of immutability - no interior mutability.

§Performance Notes

  • The view borrows the parent mask, so constructing or slicing it avoids allocating. Materialise with to_bitmask when an owned, windowed copy is required.

Structs§

BitmaskV
BitmaskView