status-go/vendor/github.com/russolsen/transit/cmap.go

91 lines
2.3 KiB
Go

// Copyright 2016 Russ Olsen. All Rights Reserved.
//
// This code is a Go port of the Java version created and maintained by Cognitect, therefore:
//
// Copyright 2014 Cognitect. All Rights Reserved.
//
// 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 transit
type CMapEntry struct {
Key interface{}
Value interface{}
}
func NewCMapEntry(key, value interface{}) *CMapEntry {
return &CMapEntry{Key: key, Value: value}
}
// CMap is used to hold maps that have composite keys (i.e. #cmap values).
// Since Go arrays and maps cannot be used as map keys, a CMap is represented
// here as a simple array of key/value entrys.
type CMap struct {
Entries []CMapEntry
}
func NewCMap() *CMap {
return &CMap{}
}
// FindBy searches thru the map, calling mf on each key in turn
// and returns the first entry for which mf evaluates to true.
func (cm CMap) FindBy(key interface{}, mf MatchF) *CMapEntry {
for _, entry := range cm.Entries {
if mf(key, entry.Key) {
return &entry
}
}
return nil
}
// Find a given key in the map and return it's corresponding value.
// The search thru the keys is done with ==, so the keys in the map
// must be comparable.
func (cm CMap) Index(keyValue interface{}) interface{} {
entry := cm.FindBy(keyValue, Equals)
if entry == nil {
return nil
}
return entry.Value
}
func (cm CMap) Put(key, value interface{}, mf MatchF) *CMap {
entry := cm.FindBy(key, mf)
if entry != nil {
entry.Value = value
} else {
entry = NewCMapEntry(key, value)
cm.Entries = append(cm.Entries, *entry)
}
return &cm
}
// Append inserts a new key/value pair w/o paying attention to
// duplicate keys.
func (cm *CMap) Append(key, value interface{}) *CMap {
entry := NewCMapEntry(key, value)
cm.Entries = append(cm.Entries, *entry)
return cm
}
// Size returns the number of key/value pairs.
func (cm *CMap) Size() int {
return len(cm.Entries)
}