imported vantiy 0.1.1 and updated debian package actually build from source

1 files changed, 143 insertions, 0 deletions

diff --git a/version.go b/version.go
new file mode 100644
index 0000000..6fcb9c1
--- /dev/null
+++ b/version.go
@@ -0,0 +1,143 @@
+package main
+
+import (
+	"fmt"
+)
+
+// Version represents a version number.
+// An element that is not present is represented as -1.
+type Version struct {
+	Major    int
+	Minor    int
+	Patch    int
+	Unstable bool
+}
+
+const unstableSuffix = "-unstable"
+
+func (v Version) String() string {
+	if v.Major < 0 {
+		panic(fmt.Sprintf("cannot stringify invalid version (major is %d)", v.Major))
+	}
+	suffix := ""
+	if v.Unstable {
+		suffix = unstableSuffix
+	}
+	if v.Minor < 0 {
+		return fmt.Sprintf("v%d%s", v.Major, suffix)
+	}
+	if v.Patch < 0 {
+		return fmt.Sprintf("v%d.%d%s", v.Major, v.Minor, suffix)
+	}
+	return fmt.Sprintf("v%d.%d.%d%s", v.Major, v.Minor, v.Patch, suffix)
+}
+
+// Less returns whether v is less than other.
+func (v Version) Less(other Version) bool {
+	if v.Major != other.Major {
+		return v.Major < other.Major
+	}
+	if v.Minor != other.Minor {
+		return v.Minor < other.Minor
+	}
+	if v.Patch != other.Patch {
+		return v.Patch < other.Patch
+	}
+	return v.Unstable && !other.Unstable
+}
+
+// Contains returns whether version v contains version other.
+// Version v is defined to contain version other when they both have the same Major
+// version and v.Minor and v.Patch are either undefined or are equal to other's.
+//
+// For example, Version{1, 1, -1} contains both Version{1, 1, -1} and Version{1, 1, 2},
+// but not Version{1, -1, -1} or Version{1, 2, -1}.
+//
+// Unstable versions (-unstable) only contain unstable versions, and stable
+// versions only contain stable versions.
+func (v Version) Contains(other Version) bool {
+	if v.Unstable != other.Unstable {
+		return false
+	}
+	if v.Patch != -1 {
+		return v == other
+	}
+	if v.Minor != -1 {
+		return v.Major == other.Major && v.Minor == other.Minor
+	}
+	return v.Major == other.Major
+}
+
+// IsValid returns trus if the version is valid.
+func (v Version) IsValid() bool {
+	return v != InvalidVersion
+}
+
+// InvalidVersion represents a version that can't be parsed.
+var InvalidVersion = Version{-1, -1, -1, false}
+
+func parseVersion(s string) (v Version, ok bool) {
+	v = InvalidVersion
+	if len(s) < 2 {
+		return
+	}
+	if s[0] != 'v' {
+		return
+	}
+	vout := InvalidVersion
+	unstable := false
+	i := 1
+	for _, vptr := range []*int{&vout.Major, &vout.Minor, &vout.Patch} {
+		*vptr, unstable, i = parseVersionPart(s, i)
+		if i < 0 {
+			return
+		}
+		if i == len(s) {
+			vout.Unstable = unstable
+			return vout, true
+		}
+	}
+	return
+}
+
+func parseVersionPart(s string, i int) (part int, unstable bool, newi int) {
+	j := i
+	for j < len(s) && s[j] != '.' && s[j] != '-' {
+		j++
+	}
+	if j == i || j-i > 1 && s[i] == '0' {
+		return -1, false, -1
+	}
+	c := s[i]
+	for {
+		if c < '0' || c > '9' {
+			return -1, false, -1
+		}
+		part *= 10
+		part += int(c - '0')
+		if part < 0 {
+			return -1, false, -1
+		}
+		i++
+		if i == len(s) {
+			return part, false, i
+		}
+		c = s[i]
+		if i+1 < len(s) {
+			if c == '.' {
+				return part, false, i + 1
+			}
+			if c == '-' && s[i:] == unstableSuffix {
+				return part, true, i + len(unstableSuffix)
+			}
+		}
+	}
+	panic("unreachable")
+}
+
+// VersionList implements sort.Interface
+type VersionList []Version
+
+func (vl VersionList) Len() int           { return len(vl) }
+func (vl VersionList) Less(i, j int) bool { return vl[i].Less(vl[j]) }
+func (vl VersionList) Swap(i, j int)      { vl[i], vl[j] = vl[j], vl[i] }