Replace bash release helper scripts with Go progam

cmd/gorepomod/internal/semver/semver.go

@@ -0,0 +1,98 @@
+package semver
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+// SemVer is the immutable semantic version per https://semver.org
+type SemVer struct {
+	major int
+	minor int
+	patch int
+}
+
+func New(major, minor, patch int) SemVer {
+	return SemVer{
+		major: major,
+		minor: minor,
+		patch: patch,
+	}
+}
+
+var zero = New(0, 0, 0)
+
+func Zero() SemVer {
+	return zero
+}
+
+// Versions implements sort.Interface to get decreasing order.
+type Versions []SemVer
+
+func (v Versions) Len() int           { return len(v) }
+func (v Versions) Less(i, j int) bool { return v[j].LessThan(v[i]) }
+func (v Versions) Swap(i, j int)      { v[i], v[j] = v[j], v[i] }
+
+func Parse(raw string) (SemVer, error) {
+	if len(raw) < 6 {
+		// e.g. minimal length is 6, e.g. "v1.2.3"
+		return zero, fmt.Errorf("%q too short to be a version", raw)
+	}
+	if raw[0] != 'v' {
+		return zero, fmt.Errorf("%q must start with letter 'v'", raw)
+	}
+	fields := strings.Split(raw[1:], ".")
+	if len(fields) < 3 {
+		return zero, fmt.Errorf("%q doesn't have the form v1.2.3", raw)
+	}
+	n := make([]int, 3)
+	for i := 0; i < 3; i++ {
+		var err error
+		n[i], err = strconv.Atoi(fields[i])
+		if err != nil {
+			return zero, err
+		}
+	}
+	return New(n[0], n[1], n[2]), nil
+}
+
+func (v SemVer) Bump(b SvBump) SemVer {
+	switch b {
+	case Major:
+		return New(v.major+1, 0, 0)
+	case Minor:
+		return New(v.major, v.minor+1, 0)
+	default:
+		return New(v.major, v.minor, v.patch+1)
+	}
+}
+
+func (v SemVer) BranchLabel() string {
+	return fmt.Sprintf("v%d.%d", v.major, v.minor)
+}
+
+func (v SemVer) String() string {
+	return fmt.Sprintf("v%d.%d.%d", v.major, v.minor, v.patch)
+}
+
+func (v SemVer) Pretty() string {
+	if v.IsZero() {
+		return ""
+	}
+	return v.String()
+}
+
+func (v SemVer) Equals(o SemVer) bool {
+	return v.major == o.major && v.minor == o.minor && v.patch == o.patch
+}
+
+func (v SemVer) LessThan(o SemVer) bool {
+	return v.major < o.major ||
+		(v.major == o.major && v.minor < o.minor) ||
+		(v.major == o.major && v.minor == o.minor && v.patch < o.patch)
+}
+
+func (v SemVer) IsZero() bool {
+	return v.Equals(zero)
+}