source: trip-planner-front/node_modules/css-tree/lib/tokenizer/char-code-definitions.js@ 6a3a178

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[6a3a178]1var EOF = 0;
2
3// https://drafts.csswg.org/css-syntax-3/
4// § 4.2. Definitions
5
6// digit
7// A code point between U+0030 DIGIT ZERO (0) and U+0039 DIGIT NINE (9).
8function isDigit(code) {
9 return code >= 0x0030 && code <= 0x0039;
10}
11
12// hex digit
13// A digit, or a code point between U+0041 LATIN CAPITAL LETTER A (A) and U+0046 LATIN CAPITAL LETTER F (F),
14// or a code point between U+0061 LATIN SMALL LETTER A (a) and U+0066 LATIN SMALL LETTER F (f).
15function isHexDigit(code) {
16 return (
17 isDigit(code) || // 0 .. 9
18 (code >= 0x0041 && code <= 0x0046) || // A .. F
19 (code >= 0x0061 && code <= 0x0066) // a .. f
20 );
21}
22
23// uppercase letter
24// A code point between U+0041 LATIN CAPITAL LETTER A (A) and U+005A LATIN CAPITAL LETTER Z (Z).
25function isUppercaseLetter(code) {
26 return code >= 0x0041 && code <= 0x005A;
27}
28
29// lowercase letter
30// A code point between U+0061 LATIN SMALL LETTER A (a) and U+007A LATIN SMALL LETTER Z (z).
31function isLowercaseLetter(code) {
32 return code >= 0x0061 && code <= 0x007A;
33}
34
35// letter
36// An uppercase letter or a lowercase letter.
37function isLetter(code) {
38 return isUppercaseLetter(code) || isLowercaseLetter(code);
39}
40
41// non-ASCII code point
42// A code point with a value equal to or greater than U+0080 <control>.
43function isNonAscii(code) {
44 return code >= 0x0080;
45}
46
47// name-start code point
48// A letter, a non-ASCII code point, or U+005F LOW LINE (_).
49function isNameStart(code) {
50 return isLetter(code) || isNonAscii(code) || code === 0x005F;
51}
52
53// name code point
54// A name-start code point, a digit, or U+002D HYPHEN-MINUS (-).
55function isName(code) {
56 return isNameStart(code) || isDigit(code) || code === 0x002D;
57}
58
59// non-printable code point
60// A code point between U+0000 NULL and U+0008 BACKSPACE, or U+000B LINE TABULATION,
61// or a code point between U+000E SHIFT OUT and U+001F INFORMATION SEPARATOR ONE, or U+007F DELETE.
62function isNonPrintable(code) {
63 return (
64 (code >= 0x0000 && code <= 0x0008) ||
65 (code === 0x000B) ||
66 (code >= 0x000E && code <= 0x001F) ||
67 (code === 0x007F)
68 );
69}
70
71// newline
72// U+000A LINE FEED. Note that U+000D CARRIAGE RETURN and U+000C FORM FEED are not included in this definition,
73// as they are converted to U+000A LINE FEED during preprocessing.
74// TODO: we doesn't do a preprocessing, so check a code point for U+000D CARRIAGE RETURN and U+000C FORM FEED
75function isNewline(code) {
76 return code === 0x000A || code === 0x000D || code === 0x000C;
77}
78
79// whitespace
80// A newline, U+0009 CHARACTER TABULATION, or U+0020 SPACE.
81function isWhiteSpace(code) {
82 return isNewline(code) || code === 0x0020 || code === 0x0009;
83}
84
85// § 4.3.8. Check if two code points are a valid escape
86function isValidEscape(first, second) {
87 // If the first code point is not U+005C REVERSE SOLIDUS (\), return false.
88 if (first !== 0x005C) {
89 return false;
90 }
91
92 // Otherwise, if the second code point is a newline or EOF, return false.
93 if (isNewline(second) || second === EOF) {
94 return false;
95 }
96
97 // Otherwise, return true.
98 return true;
99}
100
101// § 4.3.9. Check if three code points would start an identifier
102function isIdentifierStart(first, second, third) {
103 // Look at the first code point:
104
105 // U+002D HYPHEN-MINUS
106 if (first === 0x002D) {
107 // If the second code point is a name-start code point or a U+002D HYPHEN-MINUS,
108 // or the second and third code points are a valid escape, return true. Otherwise, return false.
109 return (
110 isNameStart(second) ||
111 second === 0x002D ||
112 isValidEscape(second, third)
113 );
114 }
115
116 // name-start code point
117 if (isNameStart(first)) {
118 // Return true.
119 return true;
120 }
121
122 // U+005C REVERSE SOLIDUS (\)
123 if (first === 0x005C) {
124 // If the first and second code points are a valid escape, return true. Otherwise, return false.
125 return isValidEscape(first, second);
126 }
127
128 // anything else
129 // Return false.
130 return false;
131}
132
133// § 4.3.10. Check if three code points would start a number
134function isNumberStart(first, second, third) {
135 // Look at the first code point:
136
137 // U+002B PLUS SIGN (+)
138 // U+002D HYPHEN-MINUS (-)
139 if (first === 0x002B || first === 0x002D) {
140 // If the second code point is a digit, return true.
141 if (isDigit(second)) {
142 return 2;
143 }
144
145 // Otherwise, if the second code point is a U+002E FULL STOP (.)
146 // and the third code point is a digit, return true.
147 // Otherwise, return false.
148 return second === 0x002E && isDigit(third) ? 3 : 0;
149 }
150
151 // U+002E FULL STOP (.)
152 if (first === 0x002E) {
153 // If the second code point is a digit, return true. Otherwise, return false.
154 return isDigit(second) ? 2 : 0;
155 }
156
157 // digit
158 if (isDigit(first)) {
159 // Return true.
160 return 1;
161 }
162
163 // anything else
164 // Return false.
165 return 0;
166}
167
168//
169// Misc
170//
171
172// detect BOM (https://en.wikipedia.org/wiki/Byte_order_mark)
173function isBOM(code) {
174 // UTF-16BE
175 if (code === 0xFEFF) {
176 return 1;
177 }
178
179 // UTF-16LE
180 if (code === 0xFFFE) {
181 return 1;
182 }
183
184 return 0;
185}
186
187// Fast code category
188//
189// https://drafts.csswg.org/css-syntax/#tokenizer-definitions
190// > non-ASCII code point
191// > A code point with a value equal to or greater than U+0080 <control>
192// > name-start code point
193// > A letter, a non-ASCII code point, or U+005F LOW LINE (_).
194// > name code point
195// > A name-start code point, a digit, or U+002D HYPHEN-MINUS (-)
196// That means only ASCII code points has a special meaning and we define a maps for 0..127 codes only
197var CATEGORY = new Array(0x80);
198charCodeCategory.Eof = 0x80;
199charCodeCategory.WhiteSpace = 0x82;
200charCodeCategory.Digit = 0x83;
201charCodeCategory.NameStart = 0x84;
202charCodeCategory.NonPrintable = 0x85;
203
204for (var i = 0; i < CATEGORY.length; i++) {
205 switch (true) {
206 case isWhiteSpace(i):
207 CATEGORY[i] = charCodeCategory.WhiteSpace;
208 break;
209
210 case isDigit(i):
211 CATEGORY[i] = charCodeCategory.Digit;
212 break;
213
214 case isNameStart(i):
215 CATEGORY[i] = charCodeCategory.NameStart;
216 break;
217
218 case isNonPrintable(i):
219 CATEGORY[i] = charCodeCategory.NonPrintable;
220 break;
221
222 default:
223 CATEGORY[i] = i || charCodeCategory.Eof;
224 }
225}
226
227function charCodeCategory(code) {
228 return code < 0x80 ? CATEGORY[code] : charCodeCategory.NameStart;
229};
230
231module.exports = {
232 isDigit: isDigit,
233 isHexDigit: isHexDigit,
234 isUppercaseLetter: isUppercaseLetter,
235 isLowercaseLetter: isLowercaseLetter,
236 isLetter: isLetter,
237 isNonAscii: isNonAscii,
238 isNameStart: isNameStart,
239 isName: isName,
240 isNonPrintable: isNonPrintable,
241 isNewline: isNewline,
242 isWhiteSpace: isWhiteSpace,
243 isValidEscape: isValidEscape,
244 isIdentifierStart: isIdentifierStart,
245 isNumberStart: isNumberStart,
246
247 isBOM: isBOM,
248 charCodeCategory: charCodeCategory
249};
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