1 unstable release
Uses old Rust 2015
0.9.0 | Jan 8, 2020 |
---|
#2957 in Parser implementations
Used in alt_cargo_metadata
73KB
1.5K
SLoC
semver
Semantic version parsing and comparison.
Semantic versioning (see https://semver.org/) is a set of rules for assigning version numbers.
SemVer and the Rust ecosystem
Rust itself follows the SemVer specification, as does its standard libraries. The two are not tied together.
Cargo, Rust's package manager, uses SemVer to determine which versions of packages you need installed.
Installation
To use semver
, add this to your [dependencies]
section:
semver = "0.9.0"
And this to your crate root:
extern crate semver;
Versions
At its simplest, the semver
crate allows you to construct Version
objects using the parse
method:
use semver::Version;
assert!(Version::parse("1.2.3") == Ok(Version {
major: 1,
minor: 2,
patch: 3,
pre: vec!(),
build: vec!(),
}));
If you have multiple Version
s, you can use the usual comparison operators to compare them:
use semver::Version;
assert!(Version::parse("1.2.3-alpha") != Version::parse("1.2.3-beta"));
assert!(Version::parse("1.2.3-alpha2") > Version::parse("1.2.0"));
Requirements
The semver
crate also provides the ability to compare requirements, which are more complex
comparisons.
For example, creating a requirement that only matches versions greater than or equal to 1.0.0:
use semver::Version;
use semver::VersionReq;
let r = VersionReq::parse(">= 1.0.0").unwrap();
let v = Version::parse("1.0.0").unwrap();
assert!(r.to_string() == ">= 1.0.0".to_string());
assert!(r.matches(&v))
It also allows parsing of ~x.y.z
and ^x.y.z
requirements as defined at
https://www.npmjs.org/doc/misc/semver.html
Tilde requirements specify a minimal version with some updates:
~1.2.3 := >=1.2.3 <1.3.0
~1.2 := >=1.2.0 <1.3.0
~1 := >=1.0.0 <2.0.0
Caret requirements allow SemVer compatible updates to a specified version,
0.x
and 0.x+1
are not considered compatible, but 1.x
and 1.x+1
are.
0.0.x
is not considered compatible with any other version.
Missing minor and patch versions are desugared to 0
but allow flexibility for that value.
^1.2.3 := >=1.2.3 <2.0.0
^0.2.3 := >=0.2.3 <0.3.0
^0.0.3 := >=0.0.3 <0.0.4
^0.0 := >=0.0.0 <0.1.0
^0 := >=0.0.0 <1.0.0
Dependencies
~0.1–4MB
~75K SLoC