Changelog

Source: NEWS.md

a5R 0.6.0

• Updated the bundled ‘A5’ Rust crate to 0.10.0. The lattice curve is now laid out with an L-system and the equal-area projection is more efficient; upstream reports large speed-ups for a5_polygon_to_cells(), a5_grid_disk(), a5_spherical_cap() and a5_cell_to_lonlat(). Cell identifiers are unchanged: all existing results and snapshots are bit-for-bit identical.
• a5_polygon_to_cells() gains a containment argument. The default, "centre", keeps the existing centre-in-polygon behaviour. The new "overlapping" mode additionally returns every cell that touches the polygon boundary, giving gap-free coverage; the result is a superset of the centre set. Hole interiors are still excluded in both modes. This restores the boundary-intersection use case previously served by the removed a5_grid().
• New a5_cell_edge_length_avg() returns the average edge length of a cell at a given resolution, as a units vector (metres by default). Individual edges vary from the average by roughly +/-10%.

a5R 0.5.0

CRAN release: 2026-07-02

• Removed a5_grid(), deprecated since 0.4.0. Use a5_polygon_to_cells() instead. Note the semantics differ: a5_grid() selected every cell a geometry touched (boundary intersection), whereas a5_polygon_to_cells() selects cells whose centre lies inside the geometry. For a bounding box, pass a closed polygon, e.g. a5_polygon_to_cells(wk::rct(xmin, ymin, xmax, ymax), res).
• Dropped the lifecycle R dependency and the wkt Rust dependency, both of which were only needed by a5_grid().
• Replaced the heavy geo Rust dependency with the lightweight geographiclib-rs crate for a5_cell_distance(). The haversine and rhumb methods are now computed directly; the geodesic method continues to use Karney’s algorithm. Distance results are unchanged. This removes 33 transitive crates and shrinks the vendored sources substantially.
• Updated the bundled ‘A5’ Rust crate to 0.9.0, bringing a faster polyhedral projection and an EqualAreaProjection refactor.
• a5_polygon_to_cells() now delegates hole handling to the upstream crate, which excludes hole interiors natively rather than subtracting hole-ring cells in R. Results are unchanged; the implementation is simpler and avoids an uncompact/recompact round-trip for single-part polygons.

a5R 0.4.0

CRAN release: 2026-05-14

• a5_grid() is soft-deprecated in favour of a5_polygon_to_cells(). Calling it now emits a lifecycle::deprecate_warn() with guidance: use a5_polygon_to_cells() for geometry inputs (centre-in-polygon containment), or pass a wk::rct() bounding box for the bbox use case. Note that the two functions are not semantically identical: a5_grid() uses boundary intersection (any cell touched by the geometry), whereas a5_polygon_to_cells() uses centre-point containment (cells whose centroid lies inside).
• New a5_polygon_to_cells() returns the A5 cells whose centres lie inside a polygon. Distinct from a5_grid(), which uses boundary-intersection semantics. Accepts wk-handleable geometries (including MULTIPOLYGON and sfc of several polygons), terra SpatVector objects, numeric matrices, or data.frame(lon, lat). Multi-part inputs are handled natively: per polygon part the outer ring’s cells are computed and any hole-ring cells are subtracted, then the results are unioned across parts and recompacted.
• New a5_linestring_to_cells() returns the A5 cells whose pentagons are intersected by a great-circle polyline, in discovery order along the path. Accepts the same input shapes as a5_polygon_to_cells(), including MULTILINESTRING, sfcs of multiple linestrings, and terra SpatVector objects; per-feature outputs are concatenated with first-seen deduplication.
• Bumped the embedded a5 Rust crate from 0.7.0 to 0.8.0. Transparent improvements inherited from upstream: resolution-30 (de)serialisation (a5 0.7.1), neighbour functions at resolutions 0 and 1 (a5 0.7.2), longitude normalisation in cell_to_lonlat (a5 0.7.3), faster cell_to_parent, and a polar-region spiral fix in grid_disk and spherical_cap.
• Breaking: a5_cell_to_lonlat() replaces its normalise argument with as_dataframe (default FALSE). When FALSE, centroids are returned as a wk::xy() vector with WGS 84 CRS; when TRUE, as a base data.frame with lon/lat columns. The previous normalise argument toggled longitude normalisation, but upstream a5 (>= 0.7.3) always returns normalised longitudes, so the flag’s effective job collapsed to “what container?”. as_dataframe makes that explicit. Defaults are unchanged for users who never set normalise (still returns wk::xy); explicit normalise = TRUE/FALSE calls now error and must be updated.
• New lifecycle dependency added to Imports.

a5R 0.3.1

CRAN release: 2026-03-26

• a5_cell() now requires hex strings to be exactly 16 characters, preventing silent construction of wrong cells from truncated input.
• Improved vignettes covering the new a5_cell representation and Arrow integration.

a5R 0.3.0

• a5_cell internal representation now uses 8 parallel raw byte vectors instead of hex strings, reducing memory from ~80 bytes/cell to 8 bytes/cell (#12).
• a5_cell gains vec_proxy_compare() and vec_proxy_order() methods, enabling sort(), order(), unique(), duplicated(), match(), and %in% (#12).
• a5_cell gains an is.na() method (#12).
• New a5_cell_from_arrow() and a5_cell_to_arrow() for lossless conversion between a5_cell and Arrow uint64 arrays, enabling zero-copy Parquet I/O (#12).
• New a5_u64_to_hex() and a5_hex_to_u64() for explicit conversion between a5_cell vectors and hex strings.
• a5_is_cell() has been renamed to a5_is_valid() and now accepts both a5_cell vectors and character hex strings.
• a5_cell_distance() and a5_cell_area() gain a units = NULL option to return plain numeric vectors without units class overhead.
• New vignettes: vignette("internal-cell-representation") and vignette("arrow-parquet").

a5R 0.2.0

CRAN release: 2026-03-16

• Initial CRAN submission.