packer-cn/vendor/github.com/hashicorp/go-version

Versioning Library for Go

go-version is a library for parsing versions and version constraints, and verifying versions against a set of constraints. go-version can sort a collection of versions properly, handles prerelease/beta versions, can increment versions, etc.

Versions used with go-version must follow SemVer.

Installation and Usage

Package documentation can be found on GoDoc.

Installation can be done with a normal go get:

$ go get github.com/hashicorp/go-version

Version Parsing and Comparison

v1, err := version.NewVersion("1.2")
v2, err := version.NewVersion("1.5+metadata")

// Comparison example. There is also GreaterThan, Equal, and just
// a simple Compare that returns an int allowing easy >=, <=, etc.
if v1.LessThan(v2) {
    fmt.Printf("%s is less than %s", v1, v2)
}

Version Constraints

v1, err := version.NewVersion("1.2")

// Constraints example.
constraints, err := version.NewConstraint(">= 1.0, < 1.4")
if constraints.Check(v1) {
	fmt.Printf("%s satisfies constraints %s", v1, constraints)
}

Version Sorting

versionsRaw := []string{"1.1", "0.7.1", "1.4-beta", "1.4", "2"}
versions := make([]*version.Version, len(versionsRaw))
for i, raw := range versionsRaw {
    v, _ := version.NewVersion(raw)
    versions[i] = v
}

// After this, the versions are properly sorted
sort.Sort(version.Collection(versions))

Issues and Contributing

If you find an issue with this library, please report an issue. If you'd like, we welcome any contributions. Fork this library and submit a pull request.