63 lines
1.4 KiB
Go
63 lines
1.4 KiB
Go
// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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// Package uniq provides removal of adjacent duplicate elements in slices.
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// It is similar to the unix command uniq.
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package uniq
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// ModifySlice removes adjacent duplicate elements from the given slice. It
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// adjusts the length of the slice appropriately and zeros the tail.
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//
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// ModifySlice does O(len(*slice)) operations.
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func ModifySlice[E comparable](slice *[]E) {
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// Remove duplicates
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dst := 0
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for i := 1; i < len(*slice); i++ {
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if (*slice)[i] == (*slice)[dst] {
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continue
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}
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dst++
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(*slice)[dst] = (*slice)[i]
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}
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// Zero out the elements we removed at the end of the slice
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end := dst + 1
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var zero E
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for i := end; i < len(*slice); i++ {
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(*slice)[i] = zero
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}
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// Truncate the slice
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if end < len(*slice) {
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*slice = (*slice)[:end]
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}
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}
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// ModifySliceFunc is the same as ModifySlice except that it allows using a
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// custom comparison function.
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//
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// eq should report whether the two provided elements are equal.
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func ModifySliceFunc[E any](slice *[]E, eq func(i, j E) bool) {
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// Remove duplicates
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dst := 0
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for i := 1; i < len(*slice); i++ {
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if eq((*slice)[dst], (*slice)[i]) {
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continue
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}
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dst++
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(*slice)[dst] = (*slice)[i]
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}
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// Zero out the elements we removed at the end of the slice
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end := dst + 1
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var zero E
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for i := end; i < len(*slice); i++ {
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(*slice)[i] = zero
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}
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// Truncate the slice
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if end < len(*slice) {
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*slice = (*slice)[:end]
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}
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}
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