102 lines
3.3 KiB
JavaScript
102 lines
3.3 KiB
JavaScript
import {
|
|
isName,
|
|
isValidEscape,
|
|
consumeEscaped,
|
|
decodeEscaped
|
|
} from '../tokenizer/index.js';
|
|
|
|
const REVERSE_SOLIDUS = 0x005c; // U+005C REVERSE SOLIDUS (\)
|
|
|
|
export function decode(str) {
|
|
const end = str.length - 1;
|
|
let decoded = '';
|
|
|
|
for (let i = 0; i < str.length; i++) {
|
|
let code = str.charCodeAt(i);
|
|
|
|
if (code === REVERSE_SOLIDUS) {
|
|
// special case at the ending
|
|
if (i === end) {
|
|
// if the next input code point is EOF, do nothing
|
|
break;
|
|
}
|
|
|
|
code = str.charCodeAt(++i);
|
|
|
|
// consume escaped
|
|
if (isValidEscape(REVERSE_SOLIDUS, code)) {
|
|
const escapeStart = i - 1;
|
|
const escapeEnd = consumeEscaped(str, escapeStart);
|
|
|
|
i = escapeEnd - 1;
|
|
decoded += decodeEscaped(str.substring(escapeStart + 1, escapeEnd));
|
|
} else {
|
|
// \r\n
|
|
if (code === 0x000d && str.charCodeAt(i + 1) === 0x000a) {
|
|
i++;
|
|
}
|
|
}
|
|
} else {
|
|
decoded += str[i];
|
|
}
|
|
}
|
|
|
|
return decoded;
|
|
}
|
|
|
|
// https://drafts.csswg.org/cssom/#serialize-an-identifier
|
|
// § 2.1. Common Serializing Idioms
|
|
export function encode(str) {
|
|
let encoded = '';
|
|
|
|
// If the character is the first character and is a "-" (U+002D),
|
|
// and there is no second character, then the escaped character.
|
|
// Note: That's means a single dash string "-" return as escaped dash,
|
|
// so move the condition out of the main loop
|
|
if (str.length === 1 && str.charCodeAt(0) === 0x002D) {
|
|
return '\\-';
|
|
}
|
|
|
|
// To serialize an identifier means to create a string represented
|
|
// by the concatenation of, for each character of the identifier:
|
|
for (let i = 0; i < str.length; i++) {
|
|
const code = str.charCodeAt(i);
|
|
|
|
// If the character is NULL (U+0000), then the REPLACEMENT CHARACTER (U+FFFD).
|
|
if (code === 0x0000) {
|
|
encoded += '\uFFFD';
|
|
continue;
|
|
}
|
|
|
|
if (
|
|
// If the character is in the range [\1-\1f] (U+0001 to U+001F) or is U+007F ...
|
|
// Note: Do not compare with 0x0001 since 0x0000 is precessed before
|
|
code <= 0x001F || code === 0x007F ||
|
|
// [or] ... is in the range [0-9] (U+0030 to U+0039),
|
|
(code >= 0x0030 && code <= 0x0039 && (
|
|
// If the character is the first character ...
|
|
i === 0 ||
|
|
// If the character is the second character ... and the first character is a "-" (U+002D)
|
|
i === 1 && str.charCodeAt(0) === 0x002D
|
|
))
|
|
) {
|
|
// ... then the character escaped as code point.
|
|
encoded += '\\' + code.toString(16) + ' ';
|
|
continue;
|
|
}
|
|
|
|
// If the character is not handled by one of the above rules and is greater
|
|
// than or equal to U+0080, is "-" (U+002D) or "_" (U+005F), or is in one
|
|
// of the ranges [0-9] (U+0030 to U+0039), [A-Z] (U+0041 to U+005A),
|
|
// or \[a-z] (U+0061 to U+007A), then the character itself.
|
|
if (isName(code)) {
|
|
encoded += str.charAt(i);
|
|
} else {
|
|
// Otherwise, the escaped character.
|
|
encoded += '\\' + str.charAt(i);
|
|
}
|
|
}
|
|
|
|
return encoded;
|
|
}
|