num-ordinal: ordinal number types in RustOrdinal numbers (first, second, third, ...) are usually represented as 0-based or 1-based integers. In English and most other natural languages, they're represented as 1-based numbers: first = 1st, second = 2nd, third = 3rd and so on. However, most programming languages are zero-based, i.e. when getting the first element in array or list, the index is 0. This is also true for Rust.
To make working with ordinal numbers more explicit and less error-prone, this library provides ordinal number types that can be converted to/from cardinal numbers while specifying if it is 0- or 1-based:
```rust use num_ordinal::{Ordinal, Osize};
// Osize is an ordinal usize let o = Osize::from0(3); asserteq!(&o.tostring(), "4th");
let o = Osize::from1(3); asserteq!(&o.tostring(), "third"); ```
There are also two convenience functions to create ordinal numbers when the return type can be inferred:
```rust use num_ordinal::{Osize, ordinal0, ordinal1};
// Osize is an ordinal usize let o: Osize = ordinal0(3); asserteq!(&o.tostring(), "4th");
let o: Osize = ordinal1(3); asserteq!(&o.tostring(), "third"); ```
And a macro:
```rust use num_ordinal::{O32, ordinal};
// type is inferred: let o: O32 = ordinal!(4-th);
// type can also be specified: let o = ordinal!(4-th O32); ```
Ordinal numbers implement a number of traits, so they can be compared, hashed, copied and formatted. Also, you can add or subtract an integer from an ordinal number:
```rust use num_ordinal::ordinal;
assert_eq!(ordinal!(5-th O32) - 3, ordinal!(second O32)); ```
Subtracting an ordinal from an ordinal produces an integer:
```rust use num_ordinal::ordinal;
assert_eq!(ordinal!(5-th O32) - ordinal!(second O32), 3); ```
The default value is first.
serde: Implement Serialize and Deserialize for ordinalsMIT