Crate pep440_rs

A library for python version numbers and specifiers, implementing PEP 440

use std::str::FromStr;
use pep440_rs::{VersionSpecifiers, Version, VersionSpecifier};

let version = Version::from_str("1.19").unwrap();
let version_specifier = VersionSpecifier::from_str("== 1.*").unwrap();
assert!(version_specifier.contains(&version));
let version_specifiers = VersionSpecifiers::from_str(">=1.16, <2.0").unwrap();
assert!(version_specifiers.contains(&version));

PEP 440 has a lot of unintuitive features, including:

• An epoch that you can prefix the version which, e.g. 1!1.2.3. Lower epoch always means lower version (1.0 <=2!0.1)
• post versions, which can be attached to both stable releases and pre-releases
• dev versions, which can be attached to both table releases and pre-releases. When attached to a pre-release the dev version is ordered just below the normal pre-release, however when attached to a stable version, the dev version is sorted before a pre-releases
• pre-release handling is a mess: “Pre-releases of any kind, including developmental releases, are implicitly excluded from all version specifiers, unless they are already present on the system, explicitly requested by the user, or if the only available version that satisfies the version specifier is a pre-release.”. This means that we can’t say whether a specifier matches without also looking at the environment
• pre-release vs. pre-release incl. dev is fuzzy
• local versions on top of all the others, which are added with a + and have implicitly typed string and number segments
• no semver-caret (^), but a pseudo-semver tilde (~=)
• ordering contradicts matching: We have e.g. 1.0+local > 1.0 when sorting, but ==1.0 matches 1.0+local. While the ordering of versions itself is a total order the version matching needs to catch all sorts of special cases

Structs

OperatorParseError

An error that occurs when parsing an invalid version specifier operator.

Prerelease

An optional pre-release modifier and number applied to a version.

Version

A version number such as 1.2.3 or 4!5.6.7-a8.post9.dev0.

VersionParseError

An error that occurs when parsing a Version string fails.

VersionPattern

A version number pattern.

VersionPatternParseError

An error that occurs when parsing a VersionPattern string fails.

VersionSpecifier

A version range such as >1.2.3, <=4!5.6.7-a8.post9.dev0 or == 4.1.*. Parse with VersionSpecifier::from_str

VersionSpecifierBuildError

An error that can occur when constructing a version specifier.

VersionSpecifiers

Sorted version specifiers, such as >=2.1,<3.

VersionSpecifiersParseError

Error with span information (unicode width) inside the parsed line

Enums

LocalSegment

A part of the local version identifier

Operator

One of ~= == != <= >= < > ===

PrereleaseKind

Optional pre-release modifier (alpha, beta or release candidate) appended to version

Statics

MIN_VERSION

The minimum version that can be represented by a Version: 0a0.dev0.