569 lines
14 KiB
JavaScript
Vendored
569 lines
14 KiB
JavaScript
Vendored
var Tokenizer = require('./tokenizer');
|
|
var TAB = 9;
|
|
var N = 10;
|
|
var F = 12;
|
|
var R = 13;
|
|
var SPACE = 32;
|
|
var EXCLAMATIONMARK = 33; // !
|
|
var NUMBERSIGN = 35; // #
|
|
var AMPERSAND = 38; // &
|
|
var APOSTROPHE = 39; // '
|
|
var LEFTPARENTHESIS = 40; // (
|
|
var RIGHTPARENTHESIS = 41; // )
|
|
var ASTERISK = 42; // *
|
|
var PLUSSIGN = 43; // +
|
|
var COMMA = 44; // ,
|
|
var HYPERMINUS = 45; // -
|
|
var LESSTHANSIGN = 60; // <
|
|
var GREATERTHANSIGN = 62; // >
|
|
var QUESTIONMARK = 63; // ?
|
|
var COMMERCIALAT = 64; // @
|
|
var LEFTSQUAREBRACKET = 91; // [
|
|
var RIGHTSQUAREBRACKET = 93; // ]
|
|
var LEFTCURLYBRACKET = 123; // {
|
|
var VERTICALLINE = 124; // |
|
|
var RIGHTCURLYBRACKET = 125; // }
|
|
var INFINITY = 8734; // ∞
|
|
var NAME_CHAR = createCharMap(function(ch) {
|
|
return /[a-zA-Z0-9\-]/.test(ch);
|
|
});
|
|
var COMBINATOR_PRECEDENCE = {
|
|
' ': 1,
|
|
'&&': 2,
|
|
'||': 3,
|
|
'|': 4
|
|
};
|
|
|
|
function createCharMap(fn) {
|
|
var array = typeof Uint32Array === 'function' ? new Uint32Array(128) : new Array(128);
|
|
for (var i = 0; i < 128; i++) {
|
|
array[i] = fn(String.fromCharCode(i)) ? 1 : 0;
|
|
}
|
|
return array;
|
|
}
|
|
|
|
function scanSpaces(tokenizer) {
|
|
return tokenizer.substringToPos(
|
|
tokenizer.findWsEnd(tokenizer.pos)
|
|
);
|
|
}
|
|
|
|
function scanWord(tokenizer) {
|
|
var end = tokenizer.pos;
|
|
|
|
for (; end < tokenizer.str.length; end++) {
|
|
var code = tokenizer.str.charCodeAt(end);
|
|
if (code >= 128 || NAME_CHAR[code] === 0) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (tokenizer.pos === end) {
|
|
tokenizer.error('Expect a keyword');
|
|
}
|
|
|
|
return tokenizer.substringToPos(end);
|
|
}
|
|
|
|
function scanNumber(tokenizer) {
|
|
var end = tokenizer.pos;
|
|
|
|
for (; end < tokenizer.str.length; end++) {
|
|
var code = tokenizer.str.charCodeAt(end);
|
|
if (code < 48 || code > 57) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (tokenizer.pos === end) {
|
|
tokenizer.error('Expect a number');
|
|
}
|
|
|
|
return tokenizer.substringToPos(end);
|
|
}
|
|
|
|
function scanString(tokenizer) {
|
|
var end = tokenizer.str.indexOf('\'', tokenizer.pos + 1);
|
|
|
|
if (end === -1) {
|
|
tokenizer.pos = tokenizer.str.length;
|
|
tokenizer.error('Expect an apostrophe');
|
|
}
|
|
|
|
return tokenizer.substringToPos(end + 1);
|
|
}
|
|
|
|
function readMultiplierRange(tokenizer) {
|
|
var min = null;
|
|
var max = null;
|
|
|
|
tokenizer.eat(LEFTCURLYBRACKET);
|
|
|
|
min = scanNumber(tokenizer);
|
|
|
|
if (tokenizer.charCode() === COMMA) {
|
|
tokenizer.pos++;
|
|
if (tokenizer.charCode() !== RIGHTCURLYBRACKET) {
|
|
max = scanNumber(tokenizer);
|
|
}
|
|
} else {
|
|
max = min;
|
|
}
|
|
|
|
tokenizer.eat(RIGHTCURLYBRACKET);
|
|
|
|
return {
|
|
min: Number(min),
|
|
max: max ? Number(max) : 0
|
|
};
|
|
}
|
|
|
|
function readMultiplier(tokenizer) {
|
|
var range = null;
|
|
var comma = false;
|
|
|
|
switch (tokenizer.charCode()) {
|
|
case ASTERISK:
|
|
tokenizer.pos++;
|
|
|
|
range = {
|
|
min: 0,
|
|
max: 0
|
|
};
|
|
|
|
break;
|
|
|
|
case PLUSSIGN:
|
|
tokenizer.pos++;
|
|
|
|
range = {
|
|
min: 1,
|
|
max: 0
|
|
};
|
|
|
|
break;
|
|
|
|
case QUESTIONMARK:
|
|
tokenizer.pos++;
|
|
|
|
range = {
|
|
min: 0,
|
|
max: 1
|
|
};
|
|
|
|
break;
|
|
|
|
case NUMBERSIGN:
|
|
tokenizer.pos++;
|
|
|
|
comma = true;
|
|
|
|
if (tokenizer.charCode() === LEFTCURLYBRACKET) {
|
|
range = readMultiplierRange(tokenizer);
|
|
} else {
|
|
range = {
|
|
min: 1,
|
|
max: 0
|
|
};
|
|
}
|
|
|
|
break;
|
|
|
|
case LEFTCURLYBRACKET:
|
|
range = readMultiplierRange(tokenizer);
|
|
break;
|
|
|
|
default:
|
|
return null;
|
|
}
|
|
|
|
return {
|
|
type: 'Multiplier',
|
|
comma: comma,
|
|
min: range.min,
|
|
max: range.max,
|
|
term: null
|
|
};
|
|
}
|
|
|
|
function maybeMultiplied(tokenizer, node) {
|
|
var multiplier = readMultiplier(tokenizer);
|
|
|
|
if (multiplier !== null) {
|
|
multiplier.term = node;
|
|
return multiplier;
|
|
}
|
|
|
|
return node;
|
|
}
|
|
|
|
function maybeToken(tokenizer) {
|
|
var ch = tokenizer.peek();
|
|
|
|
if (ch === '') {
|
|
return null;
|
|
}
|
|
|
|
return {
|
|
type: 'Token',
|
|
value: ch
|
|
};
|
|
}
|
|
|
|
function readProperty(tokenizer) {
|
|
var name;
|
|
|
|
tokenizer.eat(LESSTHANSIGN);
|
|
tokenizer.eat(APOSTROPHE);
|
|
|
|
name = scanWord(tokenizer);
|
|
|
|
tokenizer.eat(APOSTROPHE);
|
|
tokenizer.eat(GREATERTHANSIGN);
|
|
|
|
return maybeMultiplied(tokenizer, {
|
|
type: 'Property',
|
|
name: name
|
|
});
|
|
}
|
|
|
|
// https://drafts.csswg.org/css-values-3/#numeric-ranges
|
|
// 4.1. Range Restrictions and Range Definition Notation
|
|
//
|
|
// Range restrictions can be annotated in the numeric type notation using CSS bracketed
|
|
// range notation—[min,max]—within the angle brackets, after the identifying keyword,
|
|
// indicating a closed range between (and including) min and max.
|
|
// For example, <integer [0, 10]> indicates an integer between 0 and 10, inclusive.
|
|
function readTypeRange(tokenizer) {
|
|
// use null for Infinity to make AST format JSON serializable/deserializable
|
|
var min = null; // -Infinity
|
|
var max = null; // Infinity
|
|
var sign = 1;
|
|
|
|
tokenizer.eat(LEFTSQUAREBRACKET);
|
|
|
|
if (tokenizer.charCode() === HYPERMINUS) {
|
|
tokenizer.peek();
|
|
sign = -1;
|
|
}
|
|
|
|
if (sign == -1 && tokenizer.charCode() === INFINITY) {
|
|
tokenizer.peek();
|
|
} else {
|
|
min = sign * Number(scanNumber(tokenizer));
|
|
}
|
|
|
|
scanSpaces(tokenizer);
|
|
tokenizer.eat(COMMA);
|
|
scanSpaces(tokenizer);
|
|
|
|
if (tokenizer.charCode() === INFINITY) {
|
|
tokenizer.peek();
|
|
} else {
|
|
sign = 1;
|
|
|
|
if (tokenizer.charCode() === HYPERMINUS) {
|
|
tokenizer.peek();
|
|
sign = -1;
|
|
}
|
|
|
|
max = sign * Number(scanNumber(tokenizer));
|
|
}
|
|
|
|
tokenizer.eat(RIGHTSQUAREBRACKET);
|
|
|
|
// If no range is indicated, either by using the bracketed range notation
|
|
// or in the property description, then [−∞,∞] is assumed.
|
|
if (min === null && max === null) {
|
|
return null;
|
|
}
|
|
|
|
return {
|
|
type: 'Range',
|
|
min: min,
|
|
max: max
|
|
};
|
|
}
|
|
|
|
function readType(tokenizer) {
|
|
var name;
|
|
var opts = null;
|
|
|
|
tokenizer.eat(LESSTHANSIGN);
|
|
name = scanWord(tokenizer);
|
|
|
|
if (tokenizer.charCode() === LEFTPARENTHESIS &&
|
|
tokenizer.nextCharCode() === RIGHTPARENTHESIS) {
|
|
tokenizer.pos += 2;
|
|
name += '()';
|
|
}
|
|
|
|
if (tokenizer.charCodeAt(tokenizer.findWsEnd(tokenizer.pos)) === LEFTSQUAREBRACKET) {
|
|
scanSpaces(tokenizer);
|
|
opts = readTypeRange(tokenizer);
|
|
}
|
|
|
|
tokenizer.eat(GREATERTHANSIGN);
|
|
|
|
return maybeMultiplied(tokenizer, {
|
|
type: 'Type',
|
|
name: name,
|
|
opts: opts
|
|
});
|
|
}
|
|
|
|
function readKeywordOrFunction(tokenizer) {
|
|
var name;
|
|
|
|
name = scanWord(tokenizer);
|
|
|
|
if (tokenizer.charCode() === LEFTPARENTHESIS) {
|
|
tokenizer.pos++;
|
|
|
|
return {
|
|
type: 'Function',
|
|
name: name
|
|
};
|
|
}
|
|
|
|
return maybeMultiplied(tokenizer, {
|
|
type: 'Keyword',
|
|
name: name
|
|
});
|
|
}
|
|
|
|
function regroupTerms(terms, combinators) {
|
|
function createGroup(terms, combinator) {
|
|
return {
|
|
type: 'Group',
|
|
terms: terms,
|
|
combinator: combinator,
|
|
disallowEmpty: false,
|
|
explicit: false
|
|
};
|
|
}
|
|
|
|
combinators = Object.keys(combinators).sort(function(a, b) {
|
|
return COMBINATOR_PRECEDENCE[a] - COMBINATOR_PRECEDENCE[b];
|
|
});
|
|
|
|
while (combinators.length > 0) {
|
|
var combinator = combinators.shift();
|
|
for (var i = 0, subgroupStart = 0; i < terms.length; i++) {
|
|
var term = terms[i];
|
|
if (term.type === 'Combinator') {
|
|
if (term.value === combinator) {
|
|
if (subgroupStart === -1) {
|
|
subgroupStart = i - 1;
|
|
}
|
|
terms.splice(i, 1);
|
|
i--;
|
|
} else {
|
|
if (subgroupStart !== -1 && i - subgroupStart > 1) {
|
|
terms.splice(
|
|
subgroupStart,
|
|
i - subgroupStart,
|
|
createGroup(terms.slice(subgroupStart, i), combinator)
|
|
);
|
|
i = subgroupStart + 1;
|
|
}
|
|
subgroupStart = -1;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (subgroupStart !== -1 && combinators.length) {
|
|
terms.splice(
|
|
subgroupStart,
|
|
i - subgroupStart,
|
|
createGroup(terms.slice(subgroupStart, i), combinator)
|
|
);
|
|
}
|
|
}
|
|
|
|
return combinator;
|
|
}
|
|
|
|
function readImplicitGroup(tokenizer) {
|
|
var terms = [];
|
|
var combinators = {};
|
|
var token;
|
|
var prevToken = null;
|
|
var prevTokenPos = tokenizer.pos;
|
|
|
|
while (token = peek(tokenizer)) {
|
|
if (token.type !== 'Spaces') {
|
|
if (token.type === 'Combinator') {
|
|
// check for combinator in group beginning and double combinator sequence
|
|
if (prevToken === null || prevToken.type === 'Combinator') {
|
|
tokenizer.pos = prevTokenPos;
|
|
tokenizer.error('Unexpected combinator');
|
|
}
|
|
|
|
combinators[token.value] = true;
|
|
} else if (prevToken !== null && prevToken.type !== 'Combinator') {
|
|
combinators[' '] = true; // a b
|
|
terms.push({
|
|
type: 'Combinator',
|
|
value: ' '
|
|
});
|
|
}
|
|
|
|
terms.push(token);
|
|
prevToken = token;
|
|
prevTokenPos = tokenizer.pos;
|
|
}
|
|
}
|
|
|
|
// check for combinator in group ending
|
|
if (prevToken !== null && prevToken.type === 'Combinator') {
|
|
tokenizer.pos -= prevTokenPos;
|
|
tokenizer.error('Unexpected combinator');
|
|
}
|
|
|
|
return {
|
|
type: 'Group',
|
|
terms: terms,
|
|
combinator: regroupTerms(terms, combinators) || ' ',
|
|
disallowEmpty: false,
|
|
explicit: false
|
|
};
|
|
}
|
|
|
|
function readGroup(tokenizer) {
|
|
var result;
|
|
|
|
tokenizer.eat(LEFTSQUAREBRACKET);
|
|
result = readImplicitGroup(tokenizer);
|
|
tokenizer.eat(RIGHTSQUAREBRACKET);
|
|
|
|
result.explicit = true;
|
|
|
|
if (tokenizer.charCode() === EXCLAMATIONMARK) {
|
|
tokenizer.pos++;
|
|
result.disallowEmpty = true;
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
function peek(tokenizer) {
|
|
var code = tokenizer.charCode();
|
|
|
|
if (code < 128 && NAME_CHAR[code] === 1) {
|
|
return readKeywordOrFunction(tokenizer);
|
|
}
|
|
|
|
switch (code) {
|
|
case RIGHTSQUAREBRACKET:
|
|
// don't eat, stop scan a group
|
|
break;
|
|
|
|
case LEFTSQUAREBRACKET:
|
|
return maybeMultiplied(tokenizer, readGroup(tokenizer));
|
|
|
|
case LESSTHANSIGN:
|
|
return tokenizer.nextCharCode() === APOSTROPHE
|
|
? readProperty(tokenizer)
|
|
: readType(tokenizer);
|
|
|
|
case VERTICALLINE:
|
|
return {
|
|
type: 'Combinator',
|
|
value: tokenizer.substringToPos(
|
|
tokenizer.nextCharCode() === VERTICALLINE
|
|
? tokenizer.pos + 2
|
|
: tokenizer.pos + 1
|
|
)
|
|
};
|
|
|
|
case AMPERSAND:
|
|
tokenizer.pos++;
|
|
tokenizer.eat(AMPERSAND);
|
|
|
|
return {
|
|
type: 'Combinator',
|
|
value: '&&'
|
|
};
|
|
|
|
case COMMA:
|
|
tokenizer.pos++;
|
|
return {
|
|
type: 'Comma'
|
|
};
|
|
|
|
case APOSTROPHE:
|
|
return maybeMultiplied(tokenizer, {
|
|
type: 'String',
|
|
value: scanString(tokenizer)
|
|
});
|
|
|
|
case SPACE:
|
|
case TAB:
|
|
case N:
|
|
case R:
|
|
case F:
|
|
return {
|
|
type: 'Spaces',
|
|
value: scanSpaces(tokenizer)
|
|
};
|
|
|
|
case COMMERCIALAT:
|
|
code = tokenizer.nextCharCode();
|
|
|
|
if (code < 128 && NAME_CHAR[code] === 1) {
|
|
tokenizer.pos++;
|
|
return {
|
|
type: 'AtKeyword',
|
|
name: scanWord(tokenizer)
|
|
};
|
|
}
|
|
|
|
return maybeToken(tokenizer);
|
|
|
|
case ASTERISK:
|
|
case PLUSSIGN:
|
|
case QUESTIONMARK:
|
|
case NUMBERSIGN:
|
|
case EXCLAMATIONMARK:
|
|
// prohibited tokens (used as a multiplier start)
|
|
break;
|
|
|
|
case LEFTCURLYBRACKET:
|
|
// LEFTCURLYBRACKET is allowed since mdn/data uses it w/o quoting
|
|
// check next char isn't a number, because it's likely a disjoined multiplier
|
|
code = tokenizer.nextCharCode();
|
|
|
|
if (code < 48 || code > 57) {
|
|
return maybeToken(tokenizer);
|
|
}
|
|
|
|
break;
|
|
|
|
default:
|
|
return maybeToken(tokenizer);
|
|
}
|
|
}
|
|
|
|
function parse(source) {
|
|
var tokenizer = new Tokenizer(source);
|
|
var result = readImplicitGroup(tokenizer);
|
|
|
|
if (tokenizer.pos !== source.length) {
|
|
tokenizer.error('Unexpected input');
|
|
}
|
|
|
|
// reduce redundant groups with single group term
|
|
if (result.terms.length === 1 && result.terms[0].type === 'Group') {
|
|
result = result.terms[0];
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
// warm up parse to elimitate code branches that never execute
|
|
// fix soft deoptimizations (insufficient type feedback)
|
|
parse('[a&&<b>#|<\'c\'>*||e() f{2} /,(% g#{1,2} h{2,})]!');
|
|
|
|
module.exports = parse;
|