v0.0.643 OrderedMap

dataext/orderedMap.go

@@ -0,0 +1,164 @@
+package dataext
+
+import (
+	"fmt"
+	"iter"
+)
+
+// OrderedMap is like a normal map[TKey, TVal] - but its elements stay in order
+type OrderedMap[TKey comparable, TVal any] struct {
+	m map[TKey]*TVal
+	a []TKey
+}
+
+func NewOrderedMap[TKey comparable, TVal any](cap int) *OrderedMap[TKey, TVal] {
+	return &OrderedMap[TKey, TVal]{
+		m: make(map[TKey]*TVal, cap),
+		a: make([]TKey, 0, cap),
+	}
+}
+
+func (o *OrderedMap[TKey, TVal]) Get(key TKey) (TVal, bool) {
+	v, ok := o.m[key]
+	if ok {
+		return *v, ok
+	}
+
+	return *new(TVal), false
+}
+
+func (o *OrderedMap[TKey, TVal]) GetOrNil(key TKey) *TVal {
+	v, ok := o.m[key]
+	if ok {
+		return v
+	}
+
+	return nil
+}
+
+func (o *OrderedMap[TKey, TVal]) GetOrDefault(key TKey, defaultVal TVal) TVal {
+	v, ok := o.m[key]
+	if ok {
+		return *v
+	}
+
+	return defaultVal
+}
+
+// Add adds the new value to the map
+// At the end of the map-ordering (even if key already exists, its then "moved" to the end)
+// returns true if key already existed
+func (o *OrderedMap[TKey, TVal]) Add(key TKey, val TVal) bool {
+	if _, ok := o.m[key]; ok {
+		o.remFromArray(key)
+		o.m[key] = &val
+		o.a = append(o.a, key)
+		return true
+	}
+
+	o.m[key] = &val
+	o.a = append(o.a, key)
+	return false
+}
+
+// AddOrReplace adds the new value to the map
+// Normally at the end of the map, but if teh key already exists, its only replaced
+// returns true if key already existed
+func (o *OrderedMap[TKey, TVal]) AddOrReplace(key TKey, val TVal) bool {
+	if _, ok := o.m[key]; ok {
+		o.m[key] = &val
+		return true
+	}
+
+	o.m[key] = &val
+	o.a = append(o.a, key)
+	return false
+}
+
+func (o *OrderedMap[TKey, TVal]) Remove(key TKey) bool {
+	if _, ok := o.m[key]; ok {
+		o.remFromArray(key)
+		delete(o.m, key)
+		return true
+	}
+
+	return false
+}
+
+func (o *OrderedMap[TKey, TVal]) Iterate() iter.Seq[TVal] {
+	return func(yield func(TVal) bool) {
+		for _, v := range o.a {
+			if !yield(*o.m[v]) {
+				return
+			}
+		}
+	}
+}
+
+func (o *OrderedMap[TKey, TVal]) IterateKeys() iter.Seq[TKey] {
+	return func(yield func(TKey) bool) {
+		for _, v := range o.a {
+			if !yield(v) {
+				return
+			}
+		}
+	}
+}
+
+func (o *OrderedMap[TKey, TVal]) Array() []TVal {
+	res := make([]TVal, len(o.a))
+	for i, v := range o.a {
+		res[i] = *o.m[v]
+	}
+
+	return res
+}
+
+func (o *OrderedMap[TKey, TVal]) Keys() []TKey {
+	res := make([]TKey, len(o.a))
+	for i, v := range o.a {
+		res[i] = v
+	}
+
+	return res
+}
+
+func (o *OrderedMap[TKey, TVal]) Clear() {
+	mapCap := max(len(o.m), cap(o.a))
+	o.m = make(map[TKey]*TVal, mapCap)
+	o.a = make([]TKey, 0, mapCap)
+}
+
+func (o *OrderedMap[TKey, TVal]) Size() int {
+	return len(o.a)
+}
+
+func (o *OrderedMap[TKey, TVal]) Capacity() int {
+	return min(cap(o.a), len(o.m))
+}
+
+func (o *OrderedMap[TKey, TVal]) Contains(key TKey) bool {
+	_, ok := o.m[key]
+	return ok
+}
+
+func (o *OrderedMap[TKey, TVal]) IndexOf(key TKey) int {
+	for i, v := range o.a {
+		if v == key {
+			return i
+		}
+	}
+
+	return -1
+}
+
+func (o *OrderedMap[TKey, TVal]) remFromArray(key TKey) {
+	for i, v := range o.a {
+		if v == key {
+			o.a = append(o.a[:i], o.a[i+1:]...)
+			return
+		}
+	}
+
+	panic(fmt.Sprintf("Failed to remove key from OrderedMap -- key '%v' not found", key))
+}