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Elia Battistonc8d0d462022-02-22 16:30:51 +01001//
2// Copyright (c) 2011-2019 Canonical Ltd
3// Copyright (c) 2006-2010 Kirill Simonov
4//
5// Permission is hereby granted, free of charge, to any person obtaining a copy of
6// this software and associated documentation files (the "Software"), to deal in
7// the Software without restriction, including without limitation the rights to
8// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
9// of the Software, and to permit persons to whom the Software is furnished to do
10// so, subject to the following conditions:
11//
12// The above copyright notice and this permission notice shall be included in all
13// copies or substantial portions of the Software.
14//
15// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21// SOFTWARE.
22
23package yaml
24
25const (
26 // The size of the input raw buffer.
27 input_raw_buffer_size = 512
28
29 // The size of the input buffer.
30 // It should be possible to decode the whole raw buffer.
31 input_buffer_size = input_raw_buffer_size * 3
32
33 // The size of the output buffer.
34 output_buffer_size = 128
35
36 // The size of the output raw buffer.
37 // It should be possible to encode the whole output buffer.
38 output_raw_buffer_size = (output_buffer_size*2 + 2)
39
40 // The size of other stacks and queues.
41 initial_stack_size = 16
42 initial_queue_size = 16
43 initial_string_size = 16
44)
45
46// Check if the character at the specified position is an alphabetical
47// character, a digit, '_', or '-'.
48func is_alpha(b []byte, i int) bool {
49 return b[i] >= '0' && b[i] <= '9' || b[i] >= 'A' && b[i] <= 'Z' || b[i] >= 'a' && b[i] <= 'z' || b[i] == '_' || b[i] == '-'
50}
51
52// Check if the character at the specified position is a digit.
53func is_digit(b []byte, i int) bool {
54 return b[i] >= '0' && b[i] <= '9'
55}
56
57// Get the value of a digit.
58func as_digit(b []byte, i int) int {
59 return int(b[i]) - '0'
60}
61
62// Check if the character at the specified position is a hex-digit.
63func is_hex(b []byte, i int) bool {
64 return b[i] >= '0' && b[i] <= '9' || b[i] >= 'A' && b[i] <= 'F' || b[i] >= 'a' && b[i] <= 'f'
65}
66
67// Get the value of a hex-digit.
68func as_hex(b []byte, i int) int {
69 bi := b[i]
70 if bi >= 'A' && bi <= 'F' {
71 return int(bi) - 'A' + 10
72 }
73 if bi >= 'a' && bi <= 'f' {
74 return int(bi) - 'a' + 10
75 }
76 return int(bi) - '0'
77}
78
79// Check if the character is ASCII.
80func is_ascii(b []byte, i int) bool {
81 return b[i] <= 0x7F
82}
83
84// Check if the character at the start of the buffer can be printed unescaped.
85func is_printable(b []byte, i int) bool {
86 return ((b[i] == 0x0A) || // . == #x0A
87 (b[i] >= 0x20 && b[i] <= 0x7E) || // #x20 <= . <= #x7E
88 (b[i] == 0xC2 && b[i+1] >= 0xA0) || // #0xA0 <= . <= #xD7FF
89 (b[i] > 0xC2 && b[i] < 0xED) ||
90 (b[i] == 0xED && b[i+1] < 0xA0) ||
91 (b[i] == 0xEE) ||
92 (b[i] == 0xEF && // #xE000 <= . <= #xFFFD
93 !(b[i+1] == 0xBB && b[i+2] == 0xBF) && // && . != #xFEFF
94 !(b[i+1] == 0xBF && (b[i+2] == 0xBE || b[i+2] == 0xBF))))
95}
96
97// Check if the character at the specified position is NUL.
98func is_z(b []byte, i int) bool {
99 return b[i] == 0x00
100}
101
102// Check if the beginning of the buffer is a BOM.
103func is_bom(b []byte, i int) bool {
104 return b[0] == 0xEF && b[1] == 0xBB && b[2] == 0xBF
105}
106
107// Check if the character at the specified position is space.
108func is_space(b []byte, i int) bool {
109 return b[i] == ' '
110}
111
112// Check if the character at the specified position is tab.
113func is_tab(b []byte, i int) bool {
114 return b[i] == '\t'
115}
116
117// Check if the character at the specified position is blank (space or tab).
118func is_blank(b []byte, i int) bool {
119 //return is_space(b, i) || is_tab(b, i)
120 return b[i] == ' ' || b[i] == '\t'
121}
122
123// Check if the character at the specified position is a line break.
124func is_break(b []byte, i int) bool {
125 return (b[i] == '\r' || // CR (#xD)
126 b[i] == '\n' || // LF (#xA)
127 b[i] == 0xC2 && b[i+1] == 0x85 || // NEL (#x85)
128 b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA8 || // LS (#x2028)
129 b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA9) // PS (#x2029)
130}
131
132func is_crlf(b []byte, i int) bool {
133 return b[i] == '\r' && b[i+1] == '\n'
134}
135
136// Check if the character is a line break or NUL.
137func is_breakz(b []byte, i int) bool {
138 //return is_break(b, i) || is_z(b, i)
139 return (
140 // is_break:
141 b[i] == '\r' || // CR (#xD)
142 b[i] == '\n' || // LF (#xA)
143 b[i] == 0xC2 && b[i+1] == 0x85 || // NEL (#x85)
144 b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA8 || // LS (#x2028)
145 b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA9 || // PS (#x2029)
146 // is_z:
147 b[i] == 0)
148}
149
150// Check if the character is a line break, space, or NUL.
151func is_spacez(b []byte, i int) bool {
152 //return is_space(b, i) || is_breakz(b, i)
153 return (
154 // is_space:
155 b[i] == ' ' ||
156 // is_breakz:
157 b[i] == '\r' || // CR (#xD)
158 b[i] == '\n' || // LF (#xA)
159 b[i] == 0xC2 && b[i+1] == 0x85 || // NEL (#x85)
160 b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA8 || // LS (#x2028)
161 b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA9 || // PS (#x2029)
162 b[i] == 0)
163}
164
165// Check if the character is a line break, space, tab, or NUL.
166func is_blankz(b []byte, i int) bool {
167 //return is_blank(b, i) || is_breakz(b, i)
168 return (
169 // is_blank:
170 b[i] == ' ' || b[i] == '\t' ||
171 // is_breakz:
172 b[i] == '\r' || // CR (#xD)
173 b[i] == '\n' || // LF (#xA)
174 b[i] == 0xC2 && b[i+1] == 0x85 || // NEL (#x85)
175 b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA8 || // LS (#x2028)
176 b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA9 || // PS (#x2029)
177 b[i] == 0)
178}
179
180// Determine the width of the character.
181func width(b byte) int {
182 // Don't replace these by a switch without first
183 // confirming that it is being inlined.
184 if b&0x80 == 0x00 {
185 return 1
186 }
187 if b&0xE0 == 0xC0 {
188 return 2
189 }
190 if b&0xF0 == 0xE0 {
191 return 3
192 }
193 if b&0xF8 == 0xF0 {
194 return 4
195 }
196 return 0
197
198}