mirror of
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zeekayandHanzo Dev
b45161c43f
These three sit in luxfi/node under utils/, and P-Chain and X-Chain reach for them. Both chains have to leave that repository before it can be archived, and a chain should not have to depend on a node to measure a quantity in nLUX, keep a heap, or walk a sequence. units imports nothing at all; heap wanted only Zero, which is already here; iterator wanted heap and Zero. Three of iterator's tests exercise it against platformvm's state iterators. They stay with the node, and travel with platformvm, because a generic sequence should not be tested through one virtual machine's idea of state. What remains here covers the package on its own terms. Co-authored-by: Hanzo Dev <[email protected]>
54 lines
1.0 KiB
Go
54 lines
1.0 KiB
Go
// Copyright (C) 2019-2025, Lux Industries Inc. All rights reserved.
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// See the file LICENSE for licensing terms.
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package iterator
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import "github.com/luxfi/math/set"
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var _ Iterator[any] = (*filtered[any])(nil)
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type filtered[T any] struct {
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it Iterator[T]
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filter func(T) bool
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}
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// Filter returns an iterator that skips the elements in [it] that return true
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// from [filter].
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func Filter[T any](it Iterator[T], filter func(T) bool) Iterator[T] {
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return &filtered[T]{
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it: it,
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filter: filter,
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}
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}
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// Deduplicate returns an iterator that skips the elements that have already
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// been returned from [it].
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func Deduplicate[T comparable](it Iterator[T]) Iterator[T] {
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seen := set.Of[T]()
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return Filter(it, func(e T) bool {
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if seen.Contains(e) {
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return true
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}
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seen.Add(e)
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return false
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})
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}
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func (i *filtered[_]) Next() bool {
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for i.it.Next() {
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element := i.it.Value()
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if !i.filter(element) {
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return true
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}
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}
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return false
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}
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func (i *filtered[T]) Value() T {
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return i.it.Value()
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}
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func (i *filtered[_]) Release() {
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i.it.Release()
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}
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