A5 Cell Index Vector

Create, test, and coerce A5 cell index vectors. Cells are stored as a record with eight raw-byte fields (b1–b8) representing the little-endian bytes of the u64 cell ID. This avoids the precision loss of floating-point storage and keeps memory compact.

Usage

a5_cell(x = character())

is_a5_cell(x)

as_a5_cell(x)

Arguments

x

A character vector of hex-encoded A5 cell IDs, or an object coercible to one.

Value

An a5_cell vector (a5_cell, as_a5_cell), or a logical scalar (is_a5_cell).

Details

Ids are hex strings of up to 16 digits, optionally prefixed with 0x. Shorter ids, as some A5 libraries write them, are padded with leading zeros, and a string that is not a hex id is an error. a5_cell() does not check that an id encodes an A5 cell, so an a5_cell vector can hold values that are not cells. Check ids from outside sources, such as a file or a database, with a5_is_valid_cell().

See also

a5_is_valid_cell() to check that values are A5 cells, and a5_is_valid() for any a5R object; a5_u64_to_hex() to convert back to hex strings; a5_migrate() for ids written by a5R before 1.0.

Examples

cells <- a5_cell(c("0800000000000006", "0800000000000016"))
cells
#> <a5_cell[2]>
#> [1] 0800000000000006 0800000000000016
a5_is_valid_cell(cells)
#> [1] TRUE TRUE

# a5_cell() does not validate: this value is not a cell
a5_is_valid_cell(a5_cell("fd00000000000000"))
#> [1] FALSE