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treapmap.go
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treapmap.go
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package container
import (
"github.com/wrmsr/bane/core/container/treap"
rndu "github.com/wrmsr/bane/core/rand"
bt "github.com/wrmsr/bane/core/types"
)
type treapMapComparer[K, V any] func(kv1, kv2 bt.Kv[K, V]) int
func (c treapMapComparer[K, V]) Compare(kv1, kv2 bt.Kv[K, V]) int {
return c(kv1, kv2)
}
type TreapMap[K, V any] struct {
n *treap.TreapNode[bt.Kv[K, V]]
c treap.Comparer[bt.Kv[K, V]]
}
func NewTreapMap[K, V any](cmp treap.Comparer[K]) TreapMap[K, V] {
return TreapMap[K, V]{
c: treapMapComparer[K, V](func(v1, v2 bt.Kv[K, V]) int {
return cmp.Compare(v1.K, v2.K)
}),
}
}
var _ PersistentMap[int, string] = TreapMap[int, string]{}
func (m TreapMap[K, V]) isPersistent() {}
func (m TreapMap[K, V]) Len() int {
// TODO: memo
result := 0
m.n.ForEach(func(_ bt.Kv[K, V]) bool {
result++
return true
})
return result
}
func (m TreapMap[K, V]) Contains(k K) bool {
_, ok := m.TryGet(k)
return ok
}
func (m TreapMap[K, V]) Get(k K) V {
if v, ok := m.TryGet(k); ok {
return v
}
var z V
return z
}
func (m TreapMap[K, V]) TryGet(k K) (V, bool) {
n := m.n.Find(bt.KvOf[K, V](k, bt.Zero[V]()), m.c)
if n == nil {
var z V
return z, false
}
return n.Value.V, true
}
type treapMapIterator[K, V any] struct {
st []*treap.TreapNode[bt.Kv[K, V]]
n *treap.TreapNode[bt.Kv[K, V]]
b bool
}
var _ bt.Iterator[bt.Kv[int, string]] = &treapMapIterator[int, string]{}
func (i *treapMapIterator[K, V]) Iterate() bt.Iterator[bt.Kv[K, V]] {
return i
}
func (i *treapMapIterator[K, V]) HasNext() bool {
return i.n != nil
}
func (i *treapMapIterator[K, V]) Next() bt.Kv[K, V] {
n := i.n
if n.Right != nil {
i.n = n.Right
for i.n.Left != nil {
i.st = append(i.st, i.n)
i.n = i.n.Left
}
} else if len(i.st) > 0 {
i.n = i.st[len(i.st)-1]
i.st = i.st[:len(i.st)-1]
} else {
i.n = nil
}
return n.Value
}
func (m TreapMap[K, V]) Iterate() bt.Iterator[bt.Kv[K, V]] {
i := &treapMapIterator[K, V]{
st: make([]*treap.TreapNode[bt.Kv[K, V]], 0, 8),
n: m.n,
}
for i.n.Left != nil {
i.st = append(i.st, i.n)
i.n = i.n.Left
}
return i
}
func (m TreapMap[K, V]) ForEach(fn func(kv bt.Kv[K, V]) bool) bool {
return m.n.ForEach(func(kv bt.Kv[K, V]) bool {
return fn(kv)
})
}
func (m TreapMap[K, V]) With(k K, v V) PersistentMap[K, V] {
node := &treap.TreapNode[bt.Kv[K, V]]{
bt.KvOf(k, v),
int(rndu.FastUint32()),
nil,
nil,
}
n := m.n.Union(node, m.c, true)
return TreapMap[K, V]{n, m.c}
}
func (m TreapMap[K, V]) Without(k K) PersistentMap[K, V] {
n := m.n.Delete(bt.KvOf[K, V](k, bt.Zero[V]()), m.c)
return TreapMap[K, V]{n, m.c}
}
func (m TreapMap[K, V]) Default(k K, v V) PersistentMap[K, V] {
if _, ok := m.TryGet(k); ok {
return m
}
return m.With(k, v)
}