init

vendor/github.com/awalterschulze/gographviz/attrs.go

@@ -0,0 +1,99 @@
+//Copyright 2013 GoGraphviz 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 gographviz
+
+import (
+	"sort"
+)
+
+// Attrs represents attributes for an Edge, Node or Graph.
+type Attrs map[Attr]string
+
+// NewAttrs creates an empty Attributes type.
+func NewAttrs(m map[string]string) (Attrs, error) {
+	as := make(Attrs)
+	for k, v := range m {
+		if err := as.Add(k, v); err != nil {
+			return nil, err
+		}
+	}
+	return as, nil
+}
+
+// Add adds an attribute name and value.
+func (attrs Attrs) Add(field string, value string) error {
+	a, err := NewAttr(field)
+	if err != nil {
+		return err
+	}
+	attrs.add(a, value)
+	return nil
+}
+
+func (attrs Attrs) add(field Attr, value string) {
+	attrs[field] = value
+}
+
+// Extend adds the attributes into attrs Attrs type overwriting duplicates.
+func (attrs Attrs) Extend(more Attrs) {
+	for key, value := range more {
+		attrs.add(key, value)
+	}
+}
+
+// Ammend only adds the missing attributes to attrs Attrs type.
+func (attrs Attrs) Ammend(more Attrs) {
+	for key, value := range more {
+		if _, ok := attrs[key]; !ok {
+			attrs.add(key, value)
+		}
+	}
+}
+
+func (attrs Attrs) toMap() map[string]string {
+	m := make(map[string]string)
+	for k, v := range attrs {
+		m[string(k)] = v
+	}
+	return m
+}
+
+type attrList []Attr
+
+func (attrs attrList) Len() int { return len(attrs) }
+func (attrs attrList) Less(i, j int) bool {
+	return attrs[i] < attrs[j]
+}
+func (attrs attrList) Swap(i, j int) {
+	attrs[i], attrs[j] = attrs[j], attrs[i]
+}
+
+func (attrs Attrs) sortedNames() []Attr {
+	keys := make(attrList, 0)
+	for key := range attrs {
+		keys = append(keys, key)
+	}
+	sort.Sort(keys)
+	return []Attr(keys)
+}
+
+// Copy returns a copy of the attributes map
+func (attrs Attrs) Copy() Attrs {
+	mm := make(Attrs)
+	for k, v := range attrs {
+		mm[k] = v
+	}
+	return mm
+}