README
¶
KOMap
KOMap is short for KeepOrderMap, it provide a generic map which keeps insert order of item.
When unmarshal from JSON string, the order is determined by their occurrence in the original string.
And of cause, it will use the order too, when marshal back to JSON string.
Highly inspired by iancoleman/orderedmap, with serval differences:
- Generics support.
GetByIndexseries API.- Have a different strategy when a duplicate key is encountered while parsing a JSON object.
Status: Still WIP, API may not be the final version. Works in simple case, but not fully tested.
Usage
import (
"fmt"
"github.com/7sDream/komap"
)
func main() {
ko = komap.New[string, int]()
ko.Set("one", 1)
ko.Set("three", 2)
ko.Set("two", 2)
ko.Set("three", 3) // do not change order of key "three", it will keep ordered before two.
for i := 0; i < ko.Len(); i++ {
pair := ko.GetByIndex(i)
fmt.Printf("%s: %d\n", pair.Key, pair.Value)
}
data, _ := json.Marshal(ko)
fmt.Printf("marshal result: %s", string(data))
// Output:
// one: 1
// three: 3
// two: 2
// marshal result: {"one":1,"three":3,"two":2}
}
For all API, see document.
LICENSE
MIT. See LICENSE file.
Documentation
¶
Index ¶
- type KeepOrderMap
- func (ko *KeepOrderMap[K, V]) Delete(key K)
- func (ko *KeepOrderMap[K, V]) Get(key K) (V, bool)
- func (ko *KeepOrderMap[K, V]) GetByIndex(index int) Pair[K, V]
- func (ko *KeepOrderMap[K, V]) GetKeyByIndex(index int) K
- func (ko *KeepOrderMap[K, V]) GetOrZeroValue(key K) V
- func (ko *KeepOrderMap[K, V]) GetValueByIndex(index int) V
- func (ko *KeepOrderMap[K, V]) Keys() []K
- func (ko *KeepOrderMap[K, V]) Len() int
- func (ko KeepOrderMap[string, V]) MarshalJSON() ([]byte, error)
- func (ko *KeepOrderMap[K, V]) Pairs() []Pair[K, V]
- func (ko *KeepOrderMap[K, V]) Set(key K, value V)
- func (ko *KeepOrderMap[K, V]) SetEscapeHTML(escape bool)
- func (ko *KeepOrderMap[K, V]) Sort(lessFunc PairLessFunc[K, V])
- func (om *KeepOrderMap[string, V]) UnmarshalJSON(data []byte) error
- type Pair
- type PairLessFunc
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type KeepOrderMap ¶
type KeepOrderMap[K comparable, V any] struct { // contains filtered or unexported fields }
KeepOrderMap is a map, its kv pair keeps insert order. In JSON Unmarshal and marshal, it will use the order of keys appear in JSON string and output as is.
func (*KeepOrderMap[K, V]) Delete ¶
func (ko *KeepOrderMap[K, V]) Delete(key K)
Delete a value by key.
func (*KeepOrderMap[K, V]) Get ¶
func (ko *KeepOrderMap[K, V]) Get(key K) (V, bool)
Get a value by key. the second return value is true if the key exists, otherwise false.
func (*KeepOrderMap[K, V]) GetByIndex ¶
func (ko *KeepOrderMap[K, V]) GetByIndex(index int) Pair[K, V]
GetByIndex get the key and value by index of key order. You should make sure 0 <= i < Len(OrderedMap), panic if out of bound.
Example ¶
Use is to iterate over the map.
package main
import (
"encoding/json"
"fmt"
"github.com/7sDream/komap"
)
func main() {
ko := komap.New[string, int]()
ko.Set("one", 1)
ko.Set("three", 2)
ko.Set("two", 2)
ko.Set("three", 3) // do not change order of key "three", it will stay ahead of "two".
for i := 0; i < ko.Len(); i++ {
pair := ko.GetByIndex(i)
fmt.Printf("%s: %d\n", pair.Key, pair.Value)
}
data, _ := json.Marshal(ko)
fmt.Printf("marshal result: %s", string(data))
}
Output: one: 1 three: 3 two: 2 marshal result: {"one":1,"three":3,"two":2}
func (*KeepOrderMap[K, V]) GetKeyByIndex ¶
func (ko *KeepOrderMap[K, V]) GetKeyByIndex(index int) K
GetKeyByIndex get key by it's index in order. You should make sure 0 <= i < Len(OrderedMap), panic if out of bound.
func (*KeepOrderMap[K, V]) GetOrZeroValue ¶
func (ko *KeepOrderMap[K, V]) GetOrZeroValue(key K) V
GetOrZeroValue return stored value by key, or te zero value of value type if key not exist.
func (*KeepOrderMap[K, V]) GetValueByIndex ¶
func (ko *KeepOrderMap[K, V]) GetValueByIndex(index int) V
GetValueByIndex get the value by index of key order. You should make sure 0 <= i < Len(OrderedMap), panic if out of bound.
func (*KeepOrderMap[K, V]) Keys ¶
func (ko *KeepOrderMap[K, V]) Keys() []K
Keys returns the keys of ordered map, in current order. This will copy all keys, so you can modify it if you wish. If you want iterate over the map, maybe Len + GetByIndex is a better choice.
func (*KeepOrderMap[K, V]) Len ¶
func (ko *KeepOrderMap[K, V]) Len() int
Len returns the size of map.
func (KeepOrderMap[string, V]) MarshalJSON ¶
func (ko KeepOrderMap[string, V]) MarshalJSON() ([]byte, error)
MarshalJSON implements json.Marshaler interface. You should not call this directly, use json.Marshal(om) instead.
func (*KeepOrderMap[K, V]) Pairs ¶
func (ko *KeepOrderMap[K, V]) Pairs() []Pair[K, V]
Paris gives you all data the map stored as a list of KV pair, in current order.
func (*KeepOrderMap[K, V]) Set ¶
func (ko *KeepOrderMap[K, V]) Set(key K, value V)
Set a value by key. Called with an already exist key will not change it's order. If you want move it to the end, call Delete before Set.
func (*KeepOrderMap[K, V]) SetEscapeHTML ¶
func (ko *KeepOrderMap[K, V]) SetEscapeHTML(escape bool)
SetEscapeHTML enable or disables escape HTML chars '<' '>' '&' in marshal json result. The default value is true.
func (*KeepOrderMap[K, V]) Sort ¶
func (ko *KeepOrderMap[K, V]) Sort(lessFunc PairLessFunc[K, V])
Sort will reorder the map using the given less function.
func (*KeepOrderMap[string, V]) UnmarshalJSON ¶
func (om *KeepOrderMap[string, V]) UnmarshalJSON(data []byte) error
UnmarshalJSON implements json.Unmarshaler interface. You shouldn't call this directly, use json.Unmarshal(ko) instead.
type Pair ¶
type Pair[K, V any] struct { Key K `json:"key"` Value V `json:"value"` }
Pair is k v pair.
type PairLessFunc ¶
PairLessFunc is the less func to sort a pair list.
Source Files