From d2e12bf84bd22d2f76ff9af7e6d2f9b13b19bdc1 Mon Sep 17 00:00:00 2001
From: Benedikt Lang <github@benediktlang.de>
Date: Tue, 1 Jul 2014 22:11:26 +0200
Subject: [PATCH] First draft

---
 semver.go      | 147 +++++++++++++++++++++++++++++++++++++++++++++++++
 semver_test.go |  58 +++++++++++++++++++
 2 files changed, 205 insertions(+)
 create mode 100644 semver.go
 create mode 100644 semver_test.go

diff --git a/semver.go b/semver.go
new file mode 100644
index 0000000..69c9810
--- /dev/null
+++ b/semver.go
@@ -0,0 +1,147 @@
+package semver
+
+import (
+	"bytes"
+	"errors"
+	"strconv"
+)
+
+var SEMVER_SPEC_VERSION = Version{
+	Major: 2,
+	Minor: 0,
+	Patch: 0,
+}
+
+type Version struct {
+	Major int
+	Minor int
+	Patch int
+	Pre   []PRVersion
+	Build []string //No Precendence
+}
+
+func (v Version) String() string {
+	var buf bytes.Buffer
+	var DOT = []byte(".")
+	var HYPHEN = []byte("-")
+	var PLUS = []byte("+")
+	buf.WriteString(strconv.Itoa(v.Major))
+	buf.Write(DOT)
+	buf.WriteString(strconv.Itoa(v.Minor))
+	buf.Write(DOT)
+	buf.WriteString(strconv.Itoa(v.Patch))
+	if len(v.Pre) > 0 {
+		buf.Write(HYPHEN)
+		for i, pre := range v.Pre {
+			if i > 0 {
+				buf.Write(DOT)
+			}
+			buf.WriteString(pre.String())
+		}
+	}
+	if len(v.Build) > 0 {
+		buf.Write(PLUS)
+		for i, build := range v.Build {
+			if i > 0 {
+				buf.Write(DOT)
+			}
+			buf.WriteString(build)
+		}
+	}
+	return buf.String()
+}
+
+func (v *Version) compare(o *Version) int {
+	if v.Major != o.Major {
+		if v.Major > o.Major {
+			return 1
+		} else {
+			return -1
+		}
+	}
+	if v.Minor != o.Minor {
+		if v.Minor > o.Minor {
+			return 1
+		} else {
+			return -1
+		}
+	}
+	if v.Patch != o.Patch {
+		if v.Patch > o.Patch {
+			return 1
+		} else {
+			return -1
+		}
+	}
+
+	if len(v.Pre) == 0 && len(o.Pre) == 0 {
+		return 0
+	} else if len(v.Pre) == 0 && len(o.Pre) > 0 {
+		return -1
+	} else if len(v.Pre) > 0 && len(o.Pre) == 0 {
+		return 1
+	} else {
+		//Deep PreRelease Version comparison
+
+		return -2 //TODO: Not yet implemented
+
+	}
+
+}
+
+func Parse(s string) (*Version, error) {
+	return nil, errors.New("Not implemented yet")
+}
+
+// PreRelease Version
+type PRVersion interface {
+	compare(*PRVersion) int
+	String() string //fmt.Stringer
+	IsNumeric() bool
+}
+
+// Alphabetical PreRelease Version
+type AlphaPRVersion struct {
+	Version string
+}
+
+func (v *AlphaPRVersion) IsNumeric() bool {
+	return false
+}
+
+func (v *AlphaPRVersion) compare(o *AlphaPRVersion) int {
+	if v.Version == o.Version {
+		return 0
+	} else if v.Version > o.Version {
+		return 1
+	} else {
+		return -1
+	}
+}
+
+func (v AlphaPRVersion) String() string {
+	return v.Version
+}
+
+// Numeric PreRelease Version
+type NumPRVersion struct {
+	Version int
+}
+
+func (v *NumPRVersion) compare(o *NumPRVersion) int {
+	if v.Version == o.Version {
+		return 0
+	} else if v.Version > o.Version {
+		return 1
+	} else {
+		return -1
+	}
+}
+
+func (v NumPRVersion) String() string {
+	return strconv.Itoa(v.Version)
+}
+
+func (v *NumPRVersion) IsNumeric() bool {
+	return true
+}
diff --git a/semver_test.go b/semver_test.go
new file mode 100644
index 0000000..37868c1
--- /dev/null
+++ b/semver_test.go
@@ -0,0 +1,58 @@
+package semver
+
+import (
+	"testing"
+)
+
+func TestParse(t *testing.T) {
+
+}
+
+type stringerTest struct {
+	v      Version
+	result string
+}
+
+var stringerTests = []stringerTest{
+	{Version{1, 2, 3, nil, nil}, "1.2.3"},
+	{Version{0, 0, 1, nil, nil}, "0.0.1"},
+}
+
+func TestStringer(t *testing.T) {
+	for _, test := range stringerTests {
+		if res := test.v.String(); res != test.result {
+			t.Errorf("Stringer, expected %q but got %q", test.result, res)
+		}
+	}
+}
+
+type compareTest struct {
+	v1     Version
+	v2     Version
+	result int
+}
+
+var compareTests = []compareTest{
+	{Version{1, 0, 0, nil, nil}, Version{1, 0, 0, nil, nil}, 0},
+	{Version{2, 0, 0, nil, nil}, Version{1, 0, 0, nil, nil}, 1},
+	{Version{0, 1, 0, nil, nil}, Version{0, 1, 0, nil, nil}, 0},
+	{Version{0, 2, 0, nil, nil}, Version{0, 1, 0, nil, nil}, 1},
+	{Version{0, 0, 1, nil, nil}, Version{0, 0, 1, nil, nil}, 0},
+	{Version{0, 0, 2, nil, nil}, Version{0, 0, 1, nil, nil}, 1},
+	{Version{1, 2, 3, nil, nil}, Version{1, 2, 3, nil, nil}, 0},
+	{Version{2, 2, 4, nil, nil}, Version{1, 2, 4, nil, nil}, 1},
+	{Version{1, 3, 3, nil, nil}, Version{1, 2, 3, nil, nil}, 1},
+	{Version{1, 2, 4, nil, nil}, Version{1, 2, 3, nil, nil}, 1},
+}
+
+func TestCompare(t *testing.T) {
+	for _, test := range compareTests {
+		if res := test.v1.compare(&test.v2); res != test.result {
+			t.Errorf("Comparing %q : %q, expected %d but got %d", test.v1, test.v2, test.result, res)
+		}
+		//Test counterpart
+		if res := test.v2.compare(&test.v1); res != -test.result {
+			t.Errorf("Comparing %q : %q, expected %d but got %d", test.v2, test.v1, -test.result, res)
+		}
+	}
+}