1// 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} 199