A semi-infinite-precision integer type, implemented in Rust.

let a = Infinint::new();
assert_eq!(a.negative(), false);
assert_eq!(a.digits(), [0]);

let b = Infinint::from(123_456);
assert_eq!(b.digits(), [6, 5, 4, 3, 2, 1]);

The Infinint struct contains two elements: a boolean to identify the integer as positive or negative, and a vector of bytes containing the decimal digits. Each byte in the vector holds data for two decimal digits: one in the upper nybble, and one in the lower. The decimal digits are stored in little-endian order.

For example, the decimal number 1998 would be stored as the following two bytes:

[1000_1001, 1001_0001]

which represent these decimal digit pairs:

[(8, 9), (9, 1)]

If the number of decimal digits is uneven, the lower nybble of the final byte will be 0. For example:

137 = [0111_0011, 0001_0000] = [(7, 3), (1, 0)]