Parse tags as semver

semver.go

@@ -0,0 +1,45 @@
+package main
+
+import (
+	//"fmt"
+	"regexp"
+
+	"github.com/coreos/go-semver/semver"
+)
+
+var (
+	rxSemVerPrefix = regexp.MustCompile(`^[^\d]*`)
+)
+
+type SemVerTag struct {
+	prefix string
+	version semver.Version
+}
+
+// Return a 
+// Returns nil if the tag did not parse as semver
+func parseTagAsSemVer(tag string) *SemVerTag {
+	var prefix string
+	loc := rxSemVerPrefix.FindStringIndex(tag)
+	if loc != nil {
+		prefix = tag[:loc[1]]
+		tag = tag[loc[1]:]
+	}
+
+	version, err := semver.NewVersion(tag)
+	if err != nil {
+		return nil
+	}
+
+	svt := SemVerTag {
+		prefix,
+		*version,
+	}
+
+	return &svt
+}
+
+func (SemVerTag) asTag() string {
+	return ""
+}
+