orderedmap

README

Ordered Map for golang

OrderedMap is a Python port of OrderedDict implemented in golang. Golang's builtin map purposefully randomizes the iteration of stored key/values. OrderedMap struct preserves inserted key/value pairs; such that on iteration, key/value pairs are received in inserted (first in, first out) order.

Features

• Full support Key/Value for all data types
• Exposes an Iterator that iterates in order of insertion
• Full Get/Set/Delete map interface
• Supports Golang v1.3 through v1.10
• Supports JSON Marshal/Unmarshal
• Supports YAML Marshal/Unmarshal

Download and Install

go get github.com/fredwangwang/orderedmap

Examples

Create, Get, Set, Delete

package main

import (
    "fmt"
    "github.com/fredwangwang/orderedmap"
)

func main() {

    // Init new OrderedMap
    om := orderedmap.New()

    om.Set("a", 1)
    om.Set("b", 2)

    if val, ok := om.Get("b"); ok == true {
        fmt.Println(val)
    }

    om.Delete("a")

    if _, ok := om.Get("a"); ok == false {
        fmt.Println("c not found")
    }
    
    fmt.Println(om)
}

Iterator

n := 100
om := orderedmap.New()

for i := 0; i < n; i++ {
    om.Set(i, fmt.Sprintf("%d", i * i))
}

// Iterate though values
// - Values iteration are in insert order
// - Returned in a key/value pair struct
iter := om.IterFunc()
for kv, ok := iter(); ok; kv, ok = iter() {
    fmt.Println(kv, kv.Key, kv.Value)
}

Custom Structs

om := orderedmap.New()
om.Set("one", &MyStruct{1, 1.1})
om.Set("two", &MyStruct{2, 2.2})
om.Set("three", &MyStruct{3, 3.3})

fmt.Println(om)
// Ouput: OrderedMap[one:&{1 1.1},  two:&{2 2.2},  three:&{3 3.3}, ]

JSON marshal & unmarshal

rawPayload := `{
"number": 4,
"string": "x",
"z": 1,
"a": 2,
"b": 3,
"slice": [
  "1",
  1
],
"orderedmap": {
  "e": 1,
  "a": 2
},
"test\"ing": 9
}`

om := orderedmap.New()
json.Unmarshal([]byte(rawPayload), om)
constructedPayload, _ := json.MarshalIndent(om, "", "  ")
println(string(constructedPayload)) // will get you the same thing as rawPayload

YAML marshal & unmarshal

rawPayload := `number: 4
string: x
z: 1
a: 2
b: 3
slice:
- '1'
- 1
orderedmap:
  e: 1
  a: 2
testing: 9`

om := orderedmap.New()
yaml.Unmarshal([]byte(rawPayload), om)
constructedPayload, _ := yaml.Marshal(om)
println(string(constructedPayload)) // will get you the same thing as rawPayload

For Development

Git clone project

git clone https://github.com/fredwangwang/orderedmap.git

Build and install project

make

Run tests

make test

Documentation

Index

• type KVPair
  • func (kv1 *KVPair) Compare(kv2 *KVPair) bool
  • func (k *KVPair) String() string
• type KeyElement
• type KeyIndices
  • func (a KeyIndices) Len() int
  • func (a KeyIndices) Less(i, j int) bool
  • func (a KeyIndices) Swap(i, j int)
• type OrderedMap
  • func New() *OrderedMap
  • func NewWithArgs(args []*KVPair) *OrderedMap
  • func (om *OrderedMap) Delete(key interface{})
  • func (om *OrderedMap) Get(key interface{}) (interface{}, bool)
  • func (om *OrderedMap) Iter() <-chan *KVPair
  • func (om *OrderedMap) IterFunc() func() (*KVPair, bool)
  • func (om *OrderedMap) Len() int
  • func (om OrderedMap) MarshalJSON() ([]byte, error)
  • func (om OrderedMap) MarshalYAML() (interface{}, error)
  • func (om *OrderedMap) Set(key interface{}, value interface{})
  • func (om *OrderedMap) String() string
  • func (om *OrderedMap) UnmarshalJSON(b []byte) error
  • func (om *OrderedMap) UnmarshalYAML(unmarshal func(interface{}) error) error
  • func (om *OrderedMap) UnsafeIter() <-chan *KVPair

Types

type KVPair

type KVPair struct {
	Key   interface{}
	Value interface{}
}

func (*KVPair) Compare

func (kv1 *KVPair) Compare(kv2 *KVPair) bool

func (*KVPair) String

func (k *KVPair) String() string

type KeyElement

type KeyElement struct {
	Key   string
	Index int
}

type KeyIndices

type KeyIndices []KeyElement

func (KeyIndices) Len

func (a KeyIndices) Len() int

func (KeyIndices) Less

func (a KeyIndices) Less(i, j int) bool

func (KeyIndices) Swap

func (a KeyIndices) Swap(i, j int)

type OrderedMap

type OrderedMap struct {
	// contains filtered or unexported fields
}

func New

func New() *OrderedMap

func NewWithArgs

func NewWithArgs(args []*KVPair) *OrderedMap

func (*OrderedMap) Delete

func (om *OrderedMap) Delete(key interface{})

func (*OrderedMap) Get

func (om *OrderedMap) Get(key interface{}) (interface{}, bool)

func (*OrderedMap) Iter

func (om *OrderedMap) Iter() <-chan *KVPair

func (*OrderedMap) IterFunc

func (om *OrderedMap) IterFunc() func() (*KVPair, bool)

func (*OrderedMap) Len

func (om *OrderedMap) Len() int

func (OrderedMap) MarshalJSON

func (om OrderedMap) MarshalJSON() ([]byte, error)

func (OrderedMap) MarshalYAML

func (om OrderedMap) MarshalYAML() (interface{}, error)

func (*OrderedMap) Set

func (om *OrderedMap) Set(key interface{}, value interface{})

func (*OrderedMap) String

func (om *OrderedMap) String() string

func (*OrderedMap) UnmarshalJSON

func (om *OrderedMap) UnmarshalJSON(b []byte) error

func (*OrderedMap) UnmarshalYAML

func (om *OrderedMap) UnmarshalYAML(unmarshal func(interface{}) error) error

func (*OrderedMap) UnsafeIter

func (om *OrderedMap) UnsafeIter() <-chan *KVPair

Beware, Iterator leaks goroutines if we do not fully traverse the map. For most cases, `IterFunc()` should work as an iterator.