object

`geohash`

Geohash encoder, decoder, adjacency, covering, hierarchy, integer conversion, bit-precision, and geometry covering predicates for geographic(Latitude,Longitude) coordinates.

Availability:

logtalk_load(geohash(loader))

Author: Paulo Moura
Version: 1:2:0
Date: 2026-05-11

Compilation flags:

static, context_switching_calls

Implements:

public geohash_protocol

Imports:

public options

Uses:

geospatial
list
type

Remarks:

Alphabet: Uses the standard geohash base-32 alphabet 0123456789bcdefghjkmnpqrstuvwxyz.

Encoding canonicalization: Encoding canonicalizes longitudes to the [-180.0,180.0[ range, treating 180.0 as -180.0 so equivalent dateline coordinates map to the same geohash.

Bounding boxes: Decoded cells are represented using bbox(geographic(MinLatitude,MinLongitude),geographic(MaxLatitude,MaxLongitude)).

Coverage: Bounding-box coverage accepts antimeridian-crossing boxes where the minimum longitude is greater than the maximum longitude.

Adaptive covering: Adaptive covers use max_precision/1 together with compact/1 and min_precision/1 options.

Integer representation: Integer geohashes are 5-bit packed base-32 values with an explicit precision argument preserving leading zero groups.

Geometry covering: Polygon and polyline covering predicates rely on generic geospatial geometry predicates and do not support antimeridian-crossing input geometries.