149 lines
3.0 KiB
Go
149 lines
3.0 KiB
Go
/*
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* Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package bytealg
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// llgo:skip init CompareString
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import (
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"unsafe"
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c "github.com/goplus/llgo/runtime/internal/clite"
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"github.com/goplus/llgo/runtime/internal/runtime"
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)
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func IndexByte(b []byte, ch byte) int {
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ptr := unsafe.Pointer(unsafe.SliceData(b))
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ret := c.Memchr(ptr, c.Int(ch), uintptr(len(b)))
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if ret != nil {
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return int(uintptr(ret) - uintptr(ptr))
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}
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return -1
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}
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func IndexByteString(s string, ch byte) int {
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ptr := unsafe.Pointer(unsafe.StringData(s))
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ret := c.Memchr(ptr, c.Int(ch), uintptr(len(s)))
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if ret != nil {
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return int(uintptr(ret) - uintptr(ptr))
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}
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return -1
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}
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func Count(b []byte, c byte) (n int) {
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for _, x := range b {
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if x == c {
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n++
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}
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}
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return
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}
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func CountString(s string, c byte) (n int) {
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for i := 0; i < len(s); i++ {
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if s[i] == c {
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n++
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}
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}
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return
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}
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// Index returns the index of the first instance of b in a, or -1 if b is not present in a.
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// Requires 2 <= len(b) <= MaxLen.
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func Index(a, b []byte) int {
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for i := 0; i <= len(a)-len(b); i++ {
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if Equal(a[i:i+len(b)], b) {
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return i
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}
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}
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return -1
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}
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func Equal(a, b []byte) bool {
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if n := len(a); n == len(b) {
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return c.Memcmp(unsafe.Pointer(unsafe.SliceData(a)), unsafe.Pointer(unsafe.SliceData(b)), uintptr(n)) == 0
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}
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return false
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}
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// IndexString returns the index of the first instance of b in a, or -1 if b is not present in a.
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// Requires 2 <= len(b) <= MaxLen.
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func IndexString(a, b string) int {
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for i := 0; i <= len(a)-len(b); i++ {
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if a[i:i+len(b)] == b {
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return i
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}
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}
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return -1
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}
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// MakeNoZero makes a slice of length and capacity n without zeroing the bytes.
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// It is the caller's responsibility to ensure uninitialized bytes
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// do not leak to the end user.
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func MakeNoZero(n int) (r []byte) {
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s := (*sliceHead)(unsafe.Pointer(&r))
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s.data = runtime.AllocU(uintptr(n))
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s.len = n
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s.cap = n
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return
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}
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type sliceHead struct {
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data unsafe.Pointer
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len int
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cap int
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}
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func LastIndexByte(s []byte, c byte) int {
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for i := len(s) - 1; i >= 0; i-- {
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if s[i] == c {
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return i
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}
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}
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return -1
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}
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func LastIndexByteString(s string, c byte) int {
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for i := len(s) - 1; i >= 0; i-- {
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if s[i] == c {
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return i
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}
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}
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return -1
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}
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func CompareString(a, b string) int {
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l := len(a)
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if len(b) < l {
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l = len(b)
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}
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for i := 0; i < l; i++ {
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c1, c2 := a[i], b[i]
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if c1 < c2 {
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return -1
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}
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if c1 > c2 {
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return +1
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}
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}
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if len(a) < len(b) {
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return -1
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}
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if len(a) > len(b) {
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return +1
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}
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return 0
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}
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