generic.js•17.3 kB
import { cssWideKeywords } from './generic-const.js';
import anPlusB from './generic-an-plus-b.js';
import urange from './generic-urange.js';
import {
isIdentifierStart,
isHexDigit,
isDigit,
cmpStr,
consumeNumber,
Ident,
Function as FunctionToken,
AtKeyword,
Hash,
String as StringToken,
BadString,
Url,
BadUrl,
Delim,
Number as NumberToken,
Percentage,
Dimension,
WhiteSpace,
CDO,
CDC,
Colon,
Semicolon,
Comma,
LeftSquareBracket,
RightSquareBracket,
LeftParenthesis,
RightParenthesis,
LeftCurlyBracket,
RightCurlyBracket
} from '../tokenizer/index.js';
const calcFunctionNames = ['calc(', '-moz-calc(', '-webkit-calc('];
const balancePair = new Map([
[FunctionToken, RightParenthesis],
[LeftParenthesis, RightParenthesis],
[LeftSquareBracket, RightSquareBracket],
[LeftCurlyBracket, RightCurlyBracket]
]);
// safe char code getter
function charCodeAt(str, index) {
return index < str.length ? str.charCodeAt(index) : 0;
}
function eqStr(actual, expected) {
return cmpStr(actual, 0, actual.length, expected);
}
function eqStrAny(actual, expected) {
for (let i = 0; i < expected.length; i++) {
if (eqStr(actual, expected[i])) {
return true;
}
}
return false;
}
// IE postfix hack, i.e. 123\0 or 123px\9
function isPostfixIeHack(str, offset) {
if (offset !== str.length - 2) {
return false;
}
return (
charCodeAt(str, offset) === 0x005C && // U+005C REVERSE SOLIDUS (\)
isDigit(charCodeAt(str, offset + 1))
);
}
function outOfRange(opts, value, numEnd) {
if (opts && opts.type === 'Range') {
const num = Number(
numEnd !== undefined && numEnd !== value.length
? value.substr(0, numEnd)
: value
);
if (isNaN(num)) {
return true;
}
// FIXME: when opts.min is a string it's a dimension, skip a range validation
// for now since it requires a type covertation which is not implmented yet
if (opts.min !== null && num < opts.min && typeof opts.min !== 'string') {
return true;
}
// FIXME: when opts.max is a string it's a dimension, skip a range validation
// for now since it requires a type covertation which is not implmented yet
if (opts.max !== null && num > opts.max && typeof opts.max !== 'string') {
return true;
}
}
return false;
}
function consumeFunction(token, getNextToken) {
let balanceCloseType = 0;
let balanceStash = [];
let length = 0;
// balanced token consuming
scan:
do {
switch (token.type) {
case RightCurlyBracket:
case RightParenthesis:
case RightSquareBracket:
if (token.type !== balanceCloseType) {
break scan;
}
balanceCloseType = balanceStash.pop();
if (balanceStash.length === 0) {
length++;
break scan;
}
break;
case FunctionToken:
case LeftParenthesis:
case LeftSquareBracket:
case LeftCurlyBracket:
balanceStash.push(balanceCloseType);
balanceCloseType = balancePair.get(token.type);
break;
}
length++;
} while (token = getNextToken(length));
return length;
}
// TODO: implement
// can be used wherever <length>, <frequency>, <angle>, <time>, <percentage>, <number>, or <integer> values are allowed
// https://drafts.csswg.org/css-values/#calc-notation
function calc(next) {
return function(token, getNextToken, opts) {
if (token === null) {
return 0;
}
if (token.type === FunctionToken && eqStrAny(token.value, calcFunctionNames)) {
return consumeFunction(token, getNextToken);
}
return next(token, getNextToken, opts);
};
}
function tokenType(expectedTokenType) {
return function(token) {
if (token === null || token.type !== expectedTokenType) {
return 0;
}
return 1;
};
}
// =========================
// Complex types
//
// https://drafts.csswg.org/css-values-4/#custom-idents
// 4.2. Author-defined Identifiers: the <custom-ident> type
// Some properties accept arbitrary author-defined identifiers as a component value.
// This generic data type is denoted by <custom-ident>, and represents any valid CSS identifier
// that would not be misinterpreted as a pre-defined keyword in that property’s value definition.
//
// See also: https://developer.mozilla.org/en-US/docs/Web/CSS/custom-ident
function customIdent(token) {
if (token === null || token.type !== Ident) {
return 0;
}
const name = token.value.toLowerCase();
// The CSS-wide keywords are not valid <custom-ident>s
if (eqStrAny(name, cssWideKeywords)) {
return 0;
}
// The default keyword is reserved and is also not a valid <custom-ident>
if (eqStr(name, 'default')) {
return 0;
}
// TODO: ignore property specific keywords (as described https://developer.mozilla.org/en-US/docs/Web/CSS/custom-ident)
// Specifications using <custom-ident> must specify clearly what other keywords
// are excluded from <custom-ident>, if any—for example by saying that any pre-defined keywords
// in that property’s value definition are excluded. Excluded keywords are excluded
// in all ASCII case permutations.
return 1;
}
// https://drafts.csswg.org/css-variables/#typedef-custom-property-name
// A custom property is any property whose name starts with two dashes (U+002D HYPHEN-MINUS), like --foo.
// The <custom-property-name> production corresponds to this: it’s defined as any valid identifier
// that starts with two dashes, except -- itself, which is reserved for future use by CSS.
// NOTE: Current implementation treat `--` as a valid name since most (all?) major browsers treat it as valid.
function customPropertyName(token) {
// ... defined as any valid identifier
if (token === null || token.type !== Ident) {
return 0;
}
// ... that starts with two dashes (U+002D HYPHEN-MINUS)
if (charCodeAt(token.value, 0) !== 0x002D || charCodeAt(token.value, 1) !== 0x002D) {
return 0;
}
return 1;
}
// https://drafts.csswg.org/css-color-4/#hex-notation
// The syntax of a <hex-color> is a <hash-token> token whose value consists of 3, 4, 6, or 8 hexadecimal digits.
// In other words, a hex color is written as a hash character, "#", followed by some number of digits 0-9 or
// letters a-f (the case of the letters doesn’t matter - #00ff00 is identical to #00FF00).
function hexColor(token) {
if (token === null || token.type !== Hash) {
return 0;
}
const length = token.value.length;
// valid values (length): #rgb (4), #rgba (5), #rrggbb (7), #rrggbbaa (9)
if (length !== 4 && length !== 5 && length !== 7 && length !== 9) {
return 0;
}
for (let i = 1; i < length; i++) {
if (!isHexDigit(charCodeAt(token.value, i))) {
return 0;
}
}
return 1;
}
function idSelector(token) {
if (token === null || token.type !== Hash) {
return 0;
}
if (!isIdentifierStart(charCodeAt(token.value, 1), charCodeAt(token.value, 2), charCodeAt(token.value, 3))) {
return 0;
}
return 1;
}
// https://drafts.csswg.org/css-syntax/#any-value
// It represents the entirety of what a valid declaration can have as its value.
function declarationValue(token, getNextToken) {
if (!token) {
return 0;
}
let balanceCloseType = 0;
let balanceStash = [];
let length = 0;
// The <declaration-value> production matches any sequence of one or more tokens,
// so long as the sequence does not contain ...
scan:
do {
switch (token.type) {
// ... <bad-string-token>, <bad-url-token>,
case BadString:
case BadUrl:
break scan;
// ... unmatched <)-token>, <]-token>, or <}-token>,
case RightCurlyBracket:
case RightParenthesis:
case RightSquareBracket:
if (token.type !== balanceCloseType) {
break scan;
}
balanceCloseType = balanceStash.pop();
break;
// ... or top-level <semicolon-token> tokens
case Semicolon:
if (balanceCloseType === 0) {
break scan;
}
break;
// ... or <delim-token> tokens with a value of "!"
case Delim:
if (balanceCloseType === 0 && token.value === '!') {
break scan;
}
break;
case FunctionToken:
case LeftParenthesis:
case LeftSquareBracket:
case LeftCurlyBracket:
balanceStash.push(balanceCloseType);
balanceCloseType = balancePair.get(token.type);
break;
}
length++;
} while (token = getNextToken(length));
return length;
}
// https://drafts.csswg.org/css-syntax/#any-value
// The <any-value> production is identical to <declaration-value>, but also
// allows top-level <semicolon-token> tokens and <delim-token> tokens
// with a value of "!". It represents the entirety of what valid CSS can be in any context.
function anyValue(token, getNextToken) {
if (!token) {
return 0;
}
let balanceCloseType = 0;
let balanceStash = [];
let length = 0;
// The <any-value> production matches any sequence of one or more tokens,
// so long as the sequence ...
scan:
do {
switch (token.type) {
// ... does not contain <bad-string-token>, <bad-url-token>,
case BadString:
case BadUrl:
break scan;
// ... unmatched <)-token>, <]-token>, or <}-token>,
case RightCurlyBracket:
case RightParenthesis:
case RightSquareBracket:
if (token.type !== balanceCloseType) {
break scan;
}
balanceCloseType = balanceStash.pop();
break;
case FunctionToken:
case LeftParenthesis:
case LeftSquareBracket:
case LeftCurlyBracket:
balanceStash.push(balanceCloseType);
balanceCloseType = balancePair.get(token.type);
break;
}
length++;
} while (token = getNextToken(length));
return length;
}
// =========================
// Dimensions
//
function dimension(type) {
if (type) {
type = new Set(type);
}
return function(token, getNextToken, opts) {
if (token === null || token.type !== Dimension) {
return 0;
}
const numberEnd = consumeNumber(token.value, 0);
// check unit
if (type !== null) {
// check for IE postfix hack, i.e. 123px\0 or 123px\9
const reverseSolidusOffset = token.value.indexOf('\\', numberEnd);
const unit = reverseSolidusOffset === -1 || !isPostfixIeHack(token.value, reverseSolidusOffset)
? token.value.substr(numberEnd)
: token.value.substring(numberEnd, reverseSolidusOffset);
if (type.has(unit.toLowerCase()) === false) {
return 0;
}
}
// check range if specified
if (outOfRange(opts, token.value, numberEnd)) {
return 0;
}
return 1;
};
}
// =========================
// Percentage
//
// §5.5. Percentages: the <percentage> type
// https://drafts.csswg.org/css-values-4/#percentages
function percentage(token, getNextToken, opts) {
// ... corresponds to the <percentage-token> production
if (token === null || token.type !== Percentage) {
return 0;
}
// check range if specified
if (outOfRange(opts, token.value, token.value.length - 1)) {
return 0;
}
return 1;
}
// =========================
// Numeric
//
// https://drafts.csswg.org/css-values-4/#numbers
// The value <zero> represents a literal number with the value 0. Expressions that merely
// evaluate to a <number> with the value 0 (for example, calc(0)) do not match <zero>;
// only literal <number-token>s do.
function zero(next) {
if (typeof next !== 'function') {
next = function() {
return 0;
};
}
return function(token, getNextToken, opts) {
if (token !== null && token.type === NumberToken) {
if (Number(token.value) === 0) {
return 1;
}
}
return next(token, getNextToken, opts);
};
}
// § 5.3. Real Numbers: the <number> type
// https://drafts.csswg.org/css-values-4/#numbers
// Number values are denoted by <number>, and represent real numbers, possibly with a fractional component.
// ... It corresponds to the <number-token> production
function number(token, getNextToken, opts) {
if (token === null) {
return 0;
}
const numberEnd = consumeNumber(token.value, 0);
const isNumber = numberEnd === token.value.length;
if (!isNumber && !isPostfixIeHack(token.value, numberEnd)) {
return 0;
}
// check range if specified
if (outOfRange(opts, token.value, numberEnd)) {
return 0;
}
return 1;
}
// §5.2. Integers: the <integer> type
// https://drafts.csswg.org/css-values-4/#integers
function integer(token, getNextToken, opts) {
// ... corresponds to a subset of the <number-token> production
if (token === null || token.type !== NumberToken) {
return 0;
}
// The first digit of an integer may be immediately preceded by `-` or `+` to indicate the integer’s sign.
let i = charCodeAt(token.value, 0) === 0x002B || // U+002B PLUS SIGN (+)
charCodeAt(token.value, 0) === 0x002D ? 1 : 0; // U+002D HYPHEN-MINUS (-)
// When written literally, an integer is one or more decimal digits 0 through 9 ...
for (; i < token.value.length; i++) {
if (!isDigit(charCodeAt(token.value, i))) {
return 0;
}
}
// check range if specified
if (outOfRange(opts, token.value, i)) {
return 0;
}
return 1;
}
// token types
export const tokenTypes = {
'ident-token': tokenType(Ident),
'function-token': tokenType(FunctionToken),
'at-keyword-token': tokenType(AtKeyword),
'hash-token': tokenType(Hash),
'string-token': tokenType(StringToken),
'bad-string-token': tokenType(BadString),
'url-token': tokenType(Url),
'bad-url-token': tokenType(BadUrl),
'delim-token': tokenType(Delim),
'number-token': tokenType(NumberToken),
'percentage-token': tokenType(Percentage),
'dimension-token': tokenType(Dimension),
'whitespace-token': tokenType(WhiteSpace),
'CDO-token': tokenType(CDO),
'CDC-token': tokenType(CDC),
'colon-token': tokenType(Colon),
'semicolon-token': tokenType(Semicolon),
'comma-token': tokenType(Comma),
'[-token': tokenType(LeftSquareBracket),
']-token': tokenType(RightSquareBracket),
'(-token': tokenType(LeftParenthesis),
')-token': tokenType(RightParenthesis),
'{-token': tokenType(LeftCurlyBracket),
'}-token': tokenType(RightCurlyBracket)
};
// token production types
export const productionTypes = {
// token type aliases
'string': tokenType(StringToken),
'ident': tokenType(Ident),
// percentage
'percentage': calc(percentage),
// numeric
'zero': zero(),
'number': calc(number),
'integer': calc(integer),
// complex types
'custom-ident': customIdent,
'custom-property-name': customPropertyName,
'hex-color': hexColor,
'id-selector': idSelector, // element( <id-selector> )
'an-plus-b': anPlusB,
'urange': urange,
'declaration-value': declarationValue,
'any-value': anyValue
};
export const unitGroups = [
'length',
'angle',
'time',
'frequency',
'resolution',
'flex',
'decibel',
'semitones'
];
// dimensions types depend on units set
export function createDemensionTypes(units) {
const {
angle,
decibel,
frequency,
flex,
length,
resolution,
semitones,
time
} = units || {};
return {
'dimension': calc(dimension(null)),
'angle': calc(dimension(angle)),
'decibel': calc(dimension(decibel)),
'frequency': calc(dimension(frequency)),
'flex': calc(dimension(flex)),
'length': calc(zero(dimension(length))),
'resolution': calc(dimension(resolution)),
'semitones': calc(dimension(semitones)),
'time': calc(dimension(time))
};
}
export function createGenericTypes(units) {
return {
...tokenTypes,
...productionTypes,
...createDemensionTypes(units)
};
};