var isHexDigit = require('../../tokenizer').isHexDigit;
|
var cmpChar = require('../../tokenizer').cmpChar;
|
var TYPE = require('../../tokenizer').TYPE;
|
var NAME = require('../../tokenizer').NAME;
|
|
var IDENT = TYPE.Ident;
|
var NUMBER = TYPE.Number;
|
var DIMENSION = TYPE.Dimension;
|
var PLUSSIGN = 0x002B; // U+002B PLUS SIGN (+)
|
var HYPHENMINUS = 0x002D; // U+002D HYPHEN-MINUS (-)
|
var QUESTIONMARK = 0x003F; // U+003F QUESTION MARK (?)
|
var U = 0x0075; // U+0075 LATIN SMALL LETTER U (u)
|
|
function eatHexSequence(offset, allowDash) {
|
for (var pos = this.scanner.tokenStart + offset, len = 0; pos < this.scanner.tokenEnd; pos++) {
|
var code = this.scanner.source.charCodeAt(pos);
|
|
if (code === HYPHENMINUS && allowDash && len !== 0) {
|
if (eatHexSequence.call(this, offset + len + 1, false) === 0) {
|
this.error();
|
}
|
|
return -1;
|
}
|
|
if (!isHexDigit(code)) {
|
this.error(
|
allowDash && len !== 0
|
? 'HyphenMinus' + (len < 6 ? ' or hex digit' : '') + ' is expected'
|
: (len < 6 ? 'Hex digit is expected' : 'Unexpected input'),
|
pos
|
);
|
}
|
|
if (++len > 6) {
|
this.error('Too many hex digits', pos);
|
};
|
}
|
|
this.scanner.next();
|
return len;
|
}
|
|
function eatQuestionMarkSequence(max) {
|
var count = 0;
|
|
while (this.scanner.isDelim(QUESTIONMARK)) {
|
if (++count > max) {
|
this.error('Too many question marks');
|
}
|
|
this.scanner.next();
|
}
|
}
|
|
function startsWith(code) {
|
if (this.scanner.source.charCodeAt(this.scanner.tokenStart) !== code) {
|
this.error(NAME[code] + ' is expected');
|
}
|
}
|
|
// https://drafts.csswg.org/css-syntax/#urange
|
// Informally, the <urange> production has three forms:
|
// U+0001
|
// Defines a range consisting of a single code point, in this case the code point "1".
|
// U+0001-00ff
|
// Defines a range of codepoints between the first and the second value, in this case
|
// the range between "1" and "ff" (255 in decimal) inclusive.
|
// U+00??
|
// Defines a range of codepoints where the "?" characters range over all hex digits,
|
// in this case defining the same as the value U+0000-00ff.
|
// In each form, a maximum of 6 digits is allowed for each hexadecimal number (if you treat "?" as a hexadecimal digit).
|
//
|
// <urange> =
|
// u '+' <ident-token> '?'* |
|
// u <dimension-token> '?'* |
|
// u <number-token> '?'* |
|
// u <number-token> <dimension-token> |
|
// u <number-token> <number-token> |
|
// u '+' '?'+
|
function scanUnicodeRange() {
|
var hexLength = 0;
|
|
// u '+' <ident-token> '?'*
|
// u '+' '?'+
|
if (this.scanner.isDelim(PLUSSIGN)) {
|
this.scanner.next();
|
|
if (this.scanner.tokenType === IDENT) {
|
hexLength = eatHexSequence.call(this, 0, true);
|
if (hexLength > 0) {
|
eatQuestionMarkSequence.call(this, 6 - hexLength);
|
}
|
return;
|
}
|
|
if (this.scanner.isDelim(QUESTIONMARK)) {
|
this.scanner.next();
|
eatQuestionMarkSequence.call(this, 5);
|
return;
|
}
|
|
this.error('Hex digit or question mark is expected');
|
return;
|
}
|
|
// u <number-token> '?'*
|
// u <number-token> <dimension-token>
|
// u <number-token> <number-token>
|
if (this.scanner.tokenType === NUMBER) {
|
startsWith.call(this, PLUSSIGN);
|
hexLength = eatHexSequence.call(this, 1, true);
|
|
if (this.scanner.isDelim(QUESTIONMARK)) {
|
eatQuestionMarkSequence.call(this, 6 - hexLength);
|
return;
|
}
|
|
if (this.scanner.tokenType === DIMENSION ||
|
this.scanner.tokenType === NUMBER) {
|
startsWith.call(this, HYPHENMINUS);
|
eatHexSequence.call(this, 1, false);
|
return;
|
}
|
|
return;
|
}
|
|
// u <dimension-token> '?'*
|
if (this.scanner.tokenType === DIMENSION) {
|
startsWith.call(this, PLUSSIGN);
|
hexLength = eatHexSequence.call(this, 1, true);
|
|
if (hexLength > 0) {
|
eatQuestionMarkSequence.call(this, 6 - hexLength);
|
}
|
|
return;
|
}
|
|
this.error();
|
}
|
|
module.exports = {
|
name: 'UnicodeRange',
|
structure: {
|
value: String
|
},
|
parse: function() {
|
var start = this.scanner.tokenStart;
|
|
// U or u
|
if (!cmpChar(this.scanner.source, start, U)) {
|
this.error('U is expected');
|
}
|
|
if (!cmpChar(this.scanner.source, start + 1, PLUSSIGN)) {
|
this.error('Plus sign is expected');
|
}
|
|
this.scanner.next();
|
scanUnicodeRange.call(this);
|
|
return {
|
type: 'UnicodeRange',
|
loc: this.getLocation(start, this.scanner.tokenStart),
|
value: this.scanner.substrToCursor(start)
|
};
|
},
|
generate: function(node) {
|
this.chunk(node.value);
|
}
|
};
|
