b70b6076e3
internal/itoa wasn't around back in go 1.12 days when tinygo's syscall/errno.go was written. It was only added as of go 1.17 ( https://github.com/golang/go/commit/061a6903a232cb868780b ) so we have to have an internal copy for now. The internal copy should be deleted when tinygo drops support for go 1.16. FWIW, the new version seems nicer. It uses no allocations when converting 0, and although the optimizer might make this moot, uses a multiplication x 10 instead of a mod operation.
90 строки
1,9 КиБ
Go
90 строки
1,9 КиБ
Go
// The following is copied from Go 1.16 official implementation.
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// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package net
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// Bigger than we need, not too big to worry about overflow
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const big = 0xFFFFFF
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// Decimal to integer.
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// Returns number, characters consumed, success.
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func dtoi(s string) (n int, i int, ok bool) {
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n = 0
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for i = 0; i < len(s) && '0' <= s[i] && s[i] <= '9'; i++ {
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n = n*10 + int(s[i]-'0')
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if n >= big {
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return big, i, false
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}
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}
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if i == 0 {
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return 0, 0, false
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}
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return n, i, true
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}
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// Hexadecimal to integer.
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// Returns number, characters consumed, success.
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func xtoi(s string) (n int, i int, ok bool) {
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n = 0
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for i = 0; i < len(s); i++ {
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if '0' <= s[i] && s[i] <= '9' {
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n *= 16
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n += int(s[i] - '0')
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} else if 'a' <= s[i] && s[i] <= 'f' {
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n *= 16
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n += int(s[i]-'a') + 10
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} else if 'A' <= s[i] && s[i] <= 'F' {
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n *= 16
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n += int(s[i]-'A') + 10
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} else {
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break
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}
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if n >= big {
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return 0, i, false
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}
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}
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if i == 0 {
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return 0, i, false
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}
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return n, i, true
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}
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// xtoi2 converts the next two hex digits of s into a byte.
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// If s is longer than 2 bytes then the third byte must be e.
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// If the first two bytes of s are not hex digits or the third byte
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// does not match e, false is returned.
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func xtoi2(s string, e byte) (byte, bool) {
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if len(s) > 2 && s[2] != e {
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return 0, false
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}
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n, ei, ok := xtoi(s[:2])
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return byte(n), ok && ei == 2
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}
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// Convert i to a hexadecimal string. Leading zeros are not printed.
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func appendHex(dst []byte, i uint32) []byte {
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if i == 0 {
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return append(dst, '0')
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}
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for j := 7; j >= 0; j-- {
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v := i >> uint(j*4)
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if v > 0 {
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dst = append(dst, hexDigit[v&0xf])
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}
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}
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return dst
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}
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// Index of rightmost occurrence of b in s.
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func last(s string, b byte) int {
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i := len(s)
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for i--; i >= 0; i-- {
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if s[i] == b {
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break
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}
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}
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return i
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}
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