Add support for net.IP

src/net/parse.go

@@ -0,0 +1,96 @@
+// The following is copied from Go 1.16 official implementation.
+
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package net
+
+// Bigger than we need, not too big to worry about overflow
+const big = 0xFFFFFF
+
+// Decimal to integer.
+// Returns number, characters consumed, success.
+func dtoi(s string) (n int, i int, ok bool) {
+	n = 0
+	for i = 0; i < len(s) && '0' <= s[i] && s[i] <= '9'; i++ {
+		n = n*10 + int(s[i]-'0')
+		if n >= big {
+			return big, i, false
+		}
+	}
+	if i == 0 {
+		return 0, 0, false
+	}
+	return n, i, true
+}
+
+// Hexadecimal to integer.
+// Returns number, characters consumed, success.
+func xtoi(s string) (n int, i int, ok bool) {
+	n = 0
+	for i = 0; i < len(s); i++ {
+		if '0' <= s[i] && s[i] <= '9' {
+			n *= 16
+			n += int(s[i] - '0')
+		} else if 'a' <= s[i] && s[i] <= 'f' {
+			n *= 16
+			n += int(s[i]-'a') + 10
+		} else if 'A' <= s[i] && s[i] <= 'F' {
+			n *= 16
+			n += int(s[i]-'A') + 10
+		} else {
+			break
+		}
+		if n >= big {
+			return 0, i, false
+		}
+	}
+	if i == 0 {
+		return 0, i, false
+	}
+	return n, i, true
+}
+
+// Convert unsigned integer to decimal string.
+func uitoa(val uint) string {
+	if val == 0 { // avoid string allocation
+		return "0"
+	}
+	var buf [20]byte // big enough for 64bit value base 10
+	i := len(buf) - 1
+	for val >= 10 {
+		q := val / 10
+		buf[i] = byte('0' + val - q*10)
+		i--
+		val = q
+	}
+	// val < 10
+	buf[i] = byte('0' + val)
+	return string(buf[i:])
+}
+
+// Convert i to a hexadecimal string. Leading zeros are not printed.
+func appendHex(dst []byte, i uint32) []byte {
+	if i == 0 {
+		return append(dst, '0')
+	}
+	for j := 7; j >= 0; j-- {
+		v := i >> uint(j*4)
+		if v > 0 {
+			dst = append(dst, hexDigit[v&0xf])
+		}
+	}
+	return dst
+}
+
+// Index of rightmost occurrence of b in s.
+func last(s string, b byte) int {
+	i := len(s)
+	for i--; i >= 0; i-- {
+		if s[i] == b {
+			break
+		}
+	}
+	return i
+}