1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188
|
// Copyright 2015 Brett Vickers.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package etree
import (
"io"
"strings"
)
// A simple stack
type stack struct {
data []interface{}
}
func (s *stack) empty() bool {
return len(s.data) == 0
}
func (s *stack) push(value interface{}) {
s.data = append(s.data, value)
}
func (s *stack) pop() interface{} {
value := s.data[len(s.data)-1]
s.data[len(s.data)-1] = nil
s.data = s.data[:len(s.data)-1]
return value
}
func (s *stack) peek() interface{} {
return s.data[len(s.data)-1]
}
// A fifo is a simple first-in-first-out queue.
type fifo struct {
data []interface{}
head, tail int
}
func (f *fifo) add(value interface{}) {
if f.len()+1 >= len(f.data) {
f.grow()
}
f.data[f.tail] = value
if f.tail++; f.tail == len(f.data) {
f.tail = 0
}
}
func (f *fifo) remove() interface{} {
value := f.data[f.head]
f.data[f.head] = nil
if f.head++; f.head == len(f.data) {
f.head = 0
}
return value
}
func (f *fifo) len() int {
if f.tail >= f.head {
return f.tail - f.head
}
return len(f.data) - f.head + f.tail
}
func (f *fifo) grow() {
c := len(f.data) * 2
if c == 0 {
c = 4
}
buf, count := make([]interface{}, c), f.len()
if f.tail >= f.head {
copy(buf[0:count], f.data[f.head:f.tail])
} else {
hindex := len(f.data) - f.head
copy(buf[0:hindex], f.data[f.head:])
copy(buf[hindex:count], f.data[:f.tail])
}
f.data, f.head, f.tail = buf, 0, count
}
// countReader implements a proxy reader that counts the number of
// bytes read from its encapsulated reader.
type countReader struct {
r io.Reader
bytes int64
}
func newCountReader(r io.Reader) *countReader {
return &countReader{r: r}
}
func (cr *countReader) Read(p []byte) (n int, err error) {
b, err := cr.r.Read(p)
cr.bytes += int64(b)
return b, err
}
// countWriter implements a proxy writer that counts the number of
// bytes written by its encapsulated writer.
type countWriter struct {
w io.Writer
bytes int64
}
func newCountWriter(w io.Writer) *countWriter {
return &countWriter{w: w}
}
func (cw *countWriter) Write(p []byte) (n int, err error) {
b, err := cw.w.Write(p)
cw.bytes += int64(b)
return b, err
}
// isWhitespace returns true if the byte slice contains only
// whitespace characters.
func isWhitespace(s string) bool {
for i := 0; i < len(s); i++ {
if c := s[i]; c != ' ' && c != '\t' && c != '\n' && c != '\r' {
return false
}
}
return true
}
// spaceMatch returns true if namespace a is the empty string
// or if namespace a equals namespace b.
func spaceMatch(a, b string) bool {
switch {
case a == "":
return true
default:
return a == b
}
}
// spaceDecompose breaks a namespace:tag identifier at the ':'
// and returns the two parts.
func spaceDecompose(str string) (space, key string) {
colon := strings.IndexByte(str, ':')
if colon == -1 {
return "", str
}
return str[:colon], str[colon+1:]
}
// Strings used by crIndent
const (
crsp = "\n "
crtab = "\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t"
)
// crIndent returns a carriage return followed by n copies of the
// first non-CR character in the source string.
func crIndent(n int, source string) string {
switch {
case n < 0:
return source[:1]
case n < len(source):
return source[:n+1]
default:
return source + strings.Repeat(source[1:2], n-len(source)+1)
}
}
// nextIndex returns the index of the next occurrence of sep in s,
// starting from offset. It returns -1 if the sep string is not found.
func nextIndex(s, sep string, offset int) int {
switch i := strings.Index(s[offset:], sep); i {
case -1:
return -1
default:
return offset + i
}
}
// isInteger returns true if the string s contains an integer.
func isInteger(s string) bool {
for i := 0; i < len(s); i++ {
if (s[i] < '0' || s[i] > '9') && !(i == 0 && s[i] == '-') {
return false
}
}
return true
}
|