{
  "id": "s2_cell_token",
  "name": "S2 cell token",
  "status": "draft",
  "doc": "Token of a cell of the S2 Geometry library, which projects the sphere onto the six faces of a cube and divides each face into a hierarchy of cells along a Hilbert curve. The token is the 64-bit cell id in lowercase hexadecimal with the trailing zeros removed, so larger cells have shorter tokens, up to 16 characters. The top three bits hold the cube face (0 to 5), so a token begins with 0-9, a or b and does not end in 0; the id 0 is written X. The regexp only checks this shape, so it also matches other short hexadecimal strings.",
  "categories": [
    {
      "id": "geo",
      "name": "Geographic identifiers"
    }
  ],
  "langs": [
    {
      "id": "common",
      "name": "Common to most languages"
    }
  ],
  "is_pii": false,
  "classification": "identifier",
  "regexp": "^(?:[1-9ab]|[0-9ab][0-9a-f]{0,14}[1-9a-f])$",
  "examples": [
    {
      "value": "89c25",
      "description": "Token used in the S2 library tests"
    },
    {
      "value": "X",
      "valid": false,
      "description": "Token of the invalid cell id 0"
    },
    {
      "value": "89c250",
      "valid": false,
      "description": "Trailing zeros are removed"
    }
  ],
  "links": [
    {
      "type": "doc",
      "url": "http://s2geometry.io/devguide/s2cell_hierarchy"
    },
    {
      "type": "doc",
      "url": "https://github.com/google/s2geometry/blob/master/src/s2/s2cell_id.h"
    }
  ],
  "type": "datatype",
  "translations": {}
}