A couple of basic implementations of an arbitrary precision integer in Rust.
Only positive integers are supported and only sum and product are implemented.
Numbers are represented as binary integers and stored in an array of u8 (one digit per byte).
Parsing from a string containing a number in binary format is implemented.
Numbers are represented as integers in base 2^32 and stored in an array of u32
(hence memory usage is optimal).
Parsing from a string containing a number in decimal format is implemented.