Re-organize the bigger value package

Added some comments to undocumented methods, and also split the now too
big value.go file into smaller files.

Author: apelisse

value/fields.go

@@ -0,0 +1,81 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+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.
+*/
+
+package value
+
+import (
+	"sort"
+	"strings"
+)
+
+// Field is an individual key-value pair.
+type Field struct {
+	Name  string
+	Value Value
+}
+
+// FieldList is a list of key-value pairs. Each field is expected to
+// have a different name.
+type FieldList []Field
+
+// Sort sorts the field list by Name.
+func (f FieldList) Sort() {
+	if len(f) < 2 {
+		return
+	}
+	if len(f) == 2 {
+		if f[1].Name < f[0].Name {
+			f[0], f[1] = f[1], f[0]
+		}
+		return
+	}
+	sort.SliceStable(f, func(i, j int) bool {
+		return f[i].Name < f[j].Name
+	})
+}
+
+// Less compares two lists lexically.
+func (f FieldList) Less(rhs FieldList) bool {
+	return f.Compare(rhs) == -1
+}
+
+// Less compares two lists lexically. The result will be 0 if f==rhs, -1
+// if f < rhs, and +1 if f > rhs.
+func (f FieldList) Compare(rhs FieldList) int {
+	i := 0
+	for {
+		if i >= len(f) && i >= len(rhs) {
+			// Maps are the same length and all items are equal.
+			return 0
+		}
+		if i >= len(f) {
+			// F is shorter.
+			return -1
+		}
+		if i >= len(rhs) {
+			// RHS is shorter.
+			return 1
+		}
+		if c := strings.Compare(f[i].Name, rhs[i].Name); c != 0 {
+			return c
+		}
+		if c := Compare(f[i].Value, rhs[i].Value); c != 0 {
+			return c
+		}
+		// The items are equal; continue.
+		i++
+	}
+}

value/list.go

@@ -0,0 +1,73 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+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.
+*/
+
+package value
+
+func IsList(v Value) bool {
+	if v == nil {
+		return false
+	}
+	_, ok := v.([]interface{})
+	return ok
+}
+
+func ValueList(v Value) []interface{} {
+	return v.([]interface{})
+}
+
+// Equals compares two lists lexically.
+func ListEquals(lhs, rhs []interface{}) bool {
+	if len(lhs) != len(rhs) {
+		return false
+	}
+
+	for i, lv := range lhs {
+		if !Equals(lv, rhs[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// Less compares two lists lexically.
+func ListLess(lhs, rhs []interface{}) bool {
+	return ListCompare(lhs, rhs) == -1
+}
+
+// Compare compares two lists lexically. The result will be 0 if l==rhs, -1
+// if l < rhs, and +1 if l > rhs.
+func ListCompare(lhs, rhs []interface{}) int {
+	i := 0
+	for {
+		if i >= len(lhs) && i >= len(rhs) {
+			// Lists are the same length and all items are equal.
+			return 0
+		}
+		if i >= len(lhs) {
+			// LHS is shorter.
+			return -1
+		}
+		if i >= len(rhs) {
+			// RHS is shorter.
+			return 1
+		}
+		if c := Compare(lhs[i], rhs[i]); c != 0 {
+			return c
+		}
+		// The items are equal; continue.
+		i++
+	}
+}

value/map.go

@@ -0,0 +1,111 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+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.
+*/
+
+package value
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+)
+
+// Equals compares two maps lexically.
+func MapEquals(lhs, rhs map[string]interface{}) bool {
+	if len(lhs) != len(rhs) {
+		return false
+	}
+	for k, vl := range lhs {
+		vr, ok := rhs[k]
+		if !ok {
+			return false
+		}
+		if !Equals(vl, vr) {
+			return false
+		}
+	}
+	return true
+}
+
+// Less compares two maps lexically.
+func MapLess(lhs, rhs map[string]interface{}) bool {
+	return Compare(lhs, rhs) == -1
+}
+
+// Compare compares two maps lexically.
+func MapCompare(lhs, rhs map[string]interface{}) int {
+	lorder := make([]string, 0, len(lhs))
+	for key := range lhs {
+		lorder = append(lorder, key)
+	}
+	sort.Strings(lorder)
+	rorder := make([]string, 0, len(rhs))
+	for key := range rhs {
+		rorder = append(rorder, key)
+	}
+	sort.Strings(rorder)
+
+	i := 0
+	for {
+		if i >= len(lorder) && i >= len(rorder) {
+			// Maps are the same length and all items are equal.
+			return 0
+		}
+		if i >= len(lorder) {
+			// LHS is shorter.
+			return -1
+		}
+		if i >= len(rorder) {
+			// RHS is shorter.
+			return 1
+		}
+		if c := strings.Compare(lorder[i], rorder[i]); c != 0 {
+			return c
+		}
+		if c := Compare(lhs[lorder[i]], rhs[lorder[i]]); c != 0 {
+			return c
+		}
+		// The items are equal; continue.
+		i++
+	}
+}
+
+func IsMap(v Value) bool {
+	if _, ok := v.(map[string]interface{}); ok {
+		return true
+	} else if _, ok := v.(map[interface{}]interface{}); ok {
+		return true
+	}
+	return false
+}
+
+func ValueMap(v Value) map[string]interface{} {
+	if v == nil {
+		return map[string]interface{}{}
+	}
+	switch t := v.(type) {
+	case map[string]interface{}:
+		return t
+	case map[interface{}]interface{}:
+		m := make(map[string]interface{}, len(t))
+		for key, value := range t {
+			if ks, ok := key.(string); ok {
+				m[ks] = value
+			}
+		}
+		return m
+	}
+	panic(fmt.Errorf("not a map: %#v", v))
+}