# Versions
[](https://github.com/fosskers/rs-versions/actions)
[](https://crates.io/crates/versions)
A library for parsing and comparing software version numbers.
We like to give version numbers to our software in a myriad of different
ways. Some ways follow strict guidelines for incrementing and comparison.
Some follow conventional wisdom and are generally self-consistent. Some are
just plain asinine. This library provides a means of parsing and comparing
*any* style of versioning, be it a nice Semantic Version like this:
> 1.2.3-r1
...or a monstrosity like this:
> 2:10.2+0.0093r3+1-1
## Usage
If you're parsing several version numbers that don't follow a single scheme
(say, as in system packages), then use the [`Versioning`] type and its
parser [`Versioning::new`]. Otherwise, each main type - [`SemVer`],
[`Version`], or [`Mess`] - can be parsed on their own via the `new` method
(e.g. [`SemVer::new`]).
## Examples
```rust
use versions::Versioning;
let good = Versioning::new("1.6.0").unwrap();
let evil = Versioning::new("1.6.0a+2014+m872b87e73dfb-1").unwrap();
assert!(good.is_ideal()); // It parsed as a `SemVer`.
assert!(evil.is_complex()); // It parsed as a `Mess`.
assert!(good > evil); // We can compare them anyway!
```
## Version Constraints
Tools like `cargo` also allow version constraints to be prepended to a
version number, like in `^1.2.3`.
```rust
use versions::{Requirement, Versioning};
let req = Requirement::new("^1.2.3").unwrap();
let ver = Versioning::new("1.2.4").unwrap();
assert!(req.matches(&ver));
```
In this case, the incoming version `1.2.4` satisfies the "caret" constraint,
which demands anything greater than or equal to `1.2.3`.
See the [`Requirement`] type for more details.
## Usage with `nom`
In constructing your own [`nom`](https://lib.rs/nom) parsers, you can
integrate the parsers used for the types in this crate via
[`Versioning::parse`], [`SemVer::parse`], [`Version::parse`], and
[`Mess::parse`].
## Features
You can enable [`Serde`](https://serde.rs/) support for serialization and
deserialization with the `serde` feature.
By default the version structs are serialized/deserialized as-is. If instead
you'd like to deserialize directly from a raw version string like `1.2.3`,
see [`Versioning::deserialize_pretty`].