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// Copyright 2013-2015 CoreOS, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Semantic Versions http://semver.org
package semver
import (
"bytes"
"errors"
"fmt"
"regexp"
"strconv"
"strings"
)
type Version struct {
Major int64
Minor int64
Patch int64
PreRelease PreRelease
Metadata string
}
type PreRelease string
func splitOff(input *string, delim string) (val string) {
parts := strings.SplitN(*input, delim, 2)
if len(parts) == 2 {
*input = parts[0]
val = parts[1]
}
return val
}
func New(version string) *Version {
return Must(NewVersion(version))
}
func NewVersion(version string) (*Version, error) {
v := Version{}
if err := v.Set(version); err != nil {
return nil, err
}
return &v, nil
}
// Must is a helper for wrapping NewVersion and will panic if err is not nil.
func Must(v *Version, err error) *Version {
if err != nil {
panic(err)
}
return v
}
// Set parses and updates v from the given version string. Implements flag.Value
func (v *Version) Set(version string) error {
metadata := splitOff(&version, "+")
preRelease := PreRelease(splitOff(&version, "-"))
dotParts := strings.SplitN(version, ".", 3)
if len(dotParts) != 3 {
return fmt.Errorf("%s is not in dotted-tri format", version)
}
if err := validateIdentifier(string(preRelease)); err != nil {
return fmt.Errorf("failed to validate pre-release: %v", err)
}
if err := validateIdentifier(metadata); err != nil {
return fmt.Errorf("failed to validate metadata: %v", err)
}
parsed := make([]int64, 3, 3)
for i, v := range dotParts[:3] {
val, err := strconv.ParseInt(v, 10, 64)
parsed[i] = val
if err != nil {
return err
}
}
v.Metadata = metadata
v.PreRelease = preRelease
v.Major = parsed[0]
v.Minor = parsed[1]
v.Patch = parsed[2]
return nil
}
func (v Version) String() string {
var buffer bytes.Buffer
fmt.Fprintf(&buffer, "%d.%d.%d", v.Major, v.Minor, v.Patch)
if v.PreRelease != "" {
fmt.Fprintf(&buffer, "-%s", v.PreRelease)
}
if v.Metadata != "" {
fmt.Fprintf(&buffer, "+%s", v.Metadata)
}
return buffer.String()
}
func (v *Version) UnmarshalYAML(unmarshal func(interface{}) error) error {
var data string
if err := unmarshal(&data); err != nil {
return err
}
return v.Set(data)
}
func (v Version) MarshalJSON() ([]byte, error) {
return []byte(`"` + v.String() + `"`), nil
}
func (v *Version) UnmarshalJSON(data []byte) error {
l := len(data)
if l == 0 || string(data) == `""` {
return nil
}
if l < 2 || data[0] != '"' || data[l-1] != '"' {
return errors.New("invalid semver string")
}
return v.Set(string(data[1 : l-1]))
}
// Compare tests if v is less than, equal to, or greater than versionB,
// returning -1, 0, or +1 respectively.
func (v Version) Compare(versionB Version) int {
if cmp := recursiveCompare(v.Slice(), versionB.Slice()); cmp != 0 {
return cmp
}
return preReleaseCompare(v, versionB)
}
// Equal tests if v is equal to versionB.
func (v Version) Equal(versionB Version) bool {
return v.Compare(versionB) == 0
}
// LessThan tests if v is less than versionB.
func (v Version) LessThan(versionB Version) bool {
return v.Compare(versionB) < 0
}
// Slice converts the comparable parts of the semver into a slice of integers.
func (v Version) Slice() []int64 {
return []int64{v.Major, v.Minor, v.Patch}
}
func (p PreRelease) Slice() []string {
preRelease := string(p)
return strings.Split(preRelease, ".")
}
func preReleaseCompare(versionA Version, versionB Version) int {
a := versionA.PreRelease
b := versionB.PreRelease
/* Handle the case where if two versions are otherwise equal it is the
* one without a PreRelease that is greater */
if len(a) == 0 && (len(b) > 0) {
return 1
} else if len(b) == 0 && (len(a) > 0) {
return -1
}
// If there is a prerelease, check and compare each part.
return recursivePreReleaseCompare(a.Slice(), b.Slice())
}
func recursiveCompare(versionA []int64, versionB []int64) int {
if len(versionA) == 0 {
return 0
}
a := versionA[0]
b := versionB[0]
if a > b {
return 1
} else if a < b {
return -1
}
return recursiveCompare(versionA[1:], versionB[1:])
}
func recursivePreReleaseCompare(versionA []string, versionB []string) int {
// A larger set of pre-release fields has a higher precedence than a smaller set,
// if all of the preceding identifiers are equal.
if len(versionA) == 0 {
if len(versionB) > 0 {
return -1
}
return 0
} else if len(versionB) == 0 {
// We're longer than versionB so return 1.
return 1
}
a := versionA[0]
b := versionB[0]
aInt := false
bInt := false
aI, err := strconv.Atoi(versionA[0])
if err == nil {
aInt = true
}
bI, err := strconv.Atoi(versionB[0])
if err == nil {
bInt = true
}
// Numeric identifiers always have lower precedence than non-numeric identifiers.
if aInt && !bInt {
return -1
} else if !aInt && bInt {
return 1
}
// Handle Integer Comparison
if aInt && bInt {
if aI > bI {
return 1
} else if aI < bI {
return -1
}
}
// Handle String Comparison
if a > b {
return 1
} else if a < b {
return -1
}
return recursivePreReleaseCompare(versionA[1:], versionB[1:])
}
// BumpMajor increments the Major field by 1 and resets all other fields to their default values
func (v *Version) BumpMajor() {
v.Major += 1
v.Minor = 0
v.Patch = 0
v.PreRelease = PreRelease("")
v.Metadata = ""
}
// BumpMinor increments the Minor field by 1 and resets all other fields to their default values
func (v *Version) BumpMinor() {
v.Minor += 1
v.Patch = 0
v.PreRelease = PreRelease("")
v.Metadata = ""
}
// BumpPatch increments the Patch field by 1 and resets all other fields to their default values
func (v *Version) BumpPatch() {
v.Patch += 1
v.PreRelease = PreRelease("")
v.Metadata = ""
}
// validateIdentifier makes sure the provided identifier satisfies semver spec
func validateIdentifier(id string) error {
if id != "" && !reIdentifier.MatchString(id) {
return fmt.Errorf("%s is not a valid semver identifier", id)
}
return nil
}
// reIdentifier is a regular expression used to check that pre-release and metadata
// identifiers satisfy the spec requirements
var reIdentifier = regexp.MustCompile(`^[0-9A-Za-z-]+(\.[0-9A-Za-z-]+)*$`)