599 lines
24 KiB
JavaScript
599 lines
24 KiB
JavaScript
var TokenStream = require('../common/TokenStream');
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var adoptBuffer = require('../common/adopt-buffer');
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var constants = require('./const');
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var TYPE = constants.TYPE;
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var CHARCODE = constants.CHARCODE;
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var INPUT_STREAM_CODE = constants.INPUT_STREAM_CODE;
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var INPUT_STREAM_CODE_STRING = constants.INPUT_STREAM_CODE_STRING;
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var INPUT_STREAM_CODE_URL = constants.INPUT_STREAM_CODE_URL;
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var INPUT_STREAM_CODE_TYPE = constants.INPUT_STREAM_CODE_TYPE;
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var utils = require('./utils');
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var firstCharOffset = utils.firstCharOffset;
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var cmpStr = utils.cmpStr;
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var getNewlineLength = utils.getNewlineLength;
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var isNewline = utils.isNewline;
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var isName = utils.isName;
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var isValidEscape = utils.isValidEscape;
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var isNumberStart = utils.isNumberStart;
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var isIdentifierStart = utils.isIdentifierStart;
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var findWhiteSpaceEnd = utils.findWhiteSpaceEnd;
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var consumeEscaped = utils.consumeEscaped;
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var consumeName = utils.consumeName;
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var consumeNumber = utils.consumeNumber;
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var consumeBadUrlRemnants = utils.consumeBadUrlRemnants;
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var ASTERISK = CHARCODE.Asterisk;
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var HYPHENMINUS = CHARCODE.HyphenMinus;
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var GREATERTHANSIGN = CHARCODE.GreaterThanSign;
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var EXCLAMATIONMARK = CHARCODE.ExclamationMark;
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var PERCENTSIGN = CHARCODE.PercentSign;
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var OFFSET_MASK = 0x00FFFFFF;
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var TYPE_SHIFT = 24;
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function tokenize(source, stream) {
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function getCharCode(offset) {
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return offset < sourceLength ? source.charCodeAt(offset) : 0;
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}
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// § 4.3.3. Consume a numeric token
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function consumeNumericToken() {
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// Consume a number and let number be the result.
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offset = consumeNumber(source, offset);
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// If the next 3 input code points would start an identifier, then:
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if (isIdentifierStart(getCharCode(offset), getCharCode(offset + 1), getCharCode(offset + 2))) {
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// Create a <dimension-token> with the same value and type flag as number, and a unit set initially to the empty string.
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// Consume a name. Set the <dimension-token>’s unit to the returned value.
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// Return the <dimension-token>.
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type = TYPE.Dimension;
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offset = consumeName(source, offset);
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return;
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}
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// Otherwise, if the next input code point is U+0025 PERCENTAGE SIGN (%), consume it.
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if (getCharCode(offset) === PERCENTSIGN) {
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// Create a <percentage-token> with the same value as number, and return it.
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type = TYPE.Percentage;
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offset++;
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return;
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}
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// Otherwise, create a <number-token> with the same value and type flag as number, and return it.
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type = TYPE.Number;
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}
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// § 4.3.4. Consume an ident-like token
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function consumeIdentLikeToken() {
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const nameStartOffset = offset;
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// Consume a name, and let string be the result.
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offset = consumeName(source, offset);
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// If string’s value is an ASCII case-insensitive match for "url",
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// and the next input code point is U+0028 LEFT PARENTHESIS ((), consume it.
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if (cmpStr(source, nameStartOffset, offset, 'url') &&
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getCharCode(offset) === 0x0028) {
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// While the next two input code points are whitespace, consume the next input code point.
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// If the next one or two input code points are U+0022 QUOTATION MARK ("), U+0027 APOSTROPHE ('),
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// or whitespace followed by U+0022 QUOTATION MARK (") or U+0027 APOSTROPHE ('),
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// then create a <function-token> with its value set to string and return it.
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offset = findWhiteSpaceEnd(source, offset + 1);
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if (getCharCode(offset) === 0x0022 ||
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getCharCode(offset) === 0x0027) {
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type = TYPE.Function;
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offset = nameStartOffset + 4;
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return;
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}
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// Otherwise, consume a url token, and return it.
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consumeUrlToken();
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return;
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}
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// Otherwise, if the next input code point is U+0028 LEFT PARENTHESIS ((), consume it.
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// Create a <function-token> with its value set to string and return it.
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if (getCharCode(offset) === 0x0028) {
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type = TYPE.Function;
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offset++;
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return;
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}
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// Otherwise, create an <ident-token> with its value set to string and return it.
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type = TYPE.Ident;
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}
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// § 4.3.5. Consume a string token
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function consumeStringToken(endingCodePoint) {
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// This algorithm may be called with an ending code point, which denotes the code point
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// that ends the string. If an ending code point is not specified,
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// the current input code point is used.
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if (!endingCodePoint) {
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endingCodePoint = getCharCode(offset++);
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}
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// Initially create a <string-token> with its value set to the empty string.
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type = TYPE.String;
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// Repeatedly consume the next input code point from the stream:
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for (; offset < source.length; offset++) {
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var code = source.charCodeAt(offset);
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switch (code < 0x80 ? INPUT_STREAM_CODE_STRING[code] : code) {
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// ending code point
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case endingCodePoint:
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// Return the <string-token>.
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offset++;
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return;
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// EOF
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case INPUT_STREAM_CODE_TYPE.Eof:
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// This is a parse error. Return the <string-token>.
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return;
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// newline
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case INPUT_STREAM_CODE_TYPE.Newline:
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// This is a parse error. Reconsume the current input code point,
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// create a <bad-string-token>, and return it.
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offset += getNewlineLength(source, offset, code);
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type = TYPE.BadString;
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return;
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// U+005C REVERSE SOLIDUS (\)
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case 0x005C:
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// If the next input code point is EOF, do nothing.
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if (offset === source.length - 1) {
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break;
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}
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var nextCode = getCharCode(offset + 1);
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// Otherwise, if the next input code point is a newline, consume it.
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if (isNewline(nextCode)) {
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offset += getNewlineLength(source, offset + 1, nextCode);
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} else if (isValidEscape(code, nextCode)) {
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// Otherwise, (the stream starts with a valid escape) consume
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// an escaped code point and append the returned code point to
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// the <string-token>’s value.
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offset = consumeEscaped(source, offset) - 1;
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}
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break;
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// anything else
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// Append the current input code point to the <string-token>’s value.
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}
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}
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}
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// § 4.3.6. Consume a url token
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// Note: This algorithm assumes that the initial "url(" has already been consumed.
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// This algorithm also assumes that it’s being called to consume an "unquoted" value, like url(foo).
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// A quoted value, like url("foo"), is parsed as a <function-token>. Consume an ident-like token
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// automatically handles this distinction; this algorithm shouldn’t be called directly otherwise.
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function consumeUrlToken() {
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// Initially create a <url-token> with its value set to the empty string.
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type = TYPE.Url;
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// Consume as much whitespace as possible.
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offset = findWhiteSpaceEnd(source, offset);
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// Repeatedly consume the next input code point from the stream:
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for (; offset < source.length; offset++) {
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var code = source.charCodeAt(offset);
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switch (code < 0x80 ? INPUT_STREAM_CODE_URL[code] : code) {
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// U+0029 RIGHT PARENTHESIS ())
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case 0x0029:
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// Return the <url-token>.
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offset++;
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return;
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// EOF
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case INPUT_STREAM_CODE_TYPE.Eof:
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// This is a parse error. Return the <url-token>.
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return;
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// whitespace
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case INPUT_STREAM_CODE_TYPE.WhiteSpace:
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// Consume as much whitespace as possible.
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offset = findWhiteSpaceEnd(source, offset);
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// If the next input code point is U+0029 RIGHT PARENTHESIS ()) or EOF,
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// consume it and return the <url-token>
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// (if EOF was encountered, this is a parse error);
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if (getCharCode(offset) === 0x0029 || offset >= source.length) {
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if (offset < source.length) {
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offset++;
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}
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return;
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}
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// otherwise, consume the remnants of a bad url, create a <bad-url-token>,
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// and return it.
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offset = consumeBadUrlRemnants(source, offset);
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type = TYPE.BadUrl;
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return;
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// U+0022 QUOTATION MARK (")
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// U+0027 APOSTROPHE (')
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// U+0028 LEFT PARENTHESIS (()
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// non-printable code point
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case 0x0022:
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case 0x0027:
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case 0x0028:
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case INPUT_STREAM_CODE_TYPE.NonPrintable:
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// This is a parse error. Consume the remnants of a bad url,
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// create a <bad-url-token>, and return it.
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offset = consumeBadUrlRemnants(source, offset);
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type = TYPE.BadUrl;
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return;
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// U+005C REVERSE SOLIDUS (\)
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case 0x005C:
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// If the stream starts with a valid escape, consume an escaped code point and
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// append the returned code point to the <url-token>’s value.
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if (isValidEscape(code, getCharCode(offset + 1))) {
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offset = consumeEscaped(source, offset) - 1;
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break;
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}
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// Otherwise, this is a parse error. Consume the remnants of a bad url,
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// create a <bad-url-token>, and return it.
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offset = consumeBadUrlRemnants(source, offset);
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type = TYPE.BadUrl;
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return;
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// anything else
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// Append the current input code point to the <url-token>’s value.
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}
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}
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}
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if (!stream) {
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stream = new TokenStream();
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}
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// ensure source is a string
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source = String(source || '');
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var start = firstCharOffset(source);
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var sourceLength = source.length;
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var offsetAndType = adoptBuffer(stream.offsetAndType, sourceLength + 1); // +1 because of eof-token
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var balance = adoptBuffer(stream.balance, sourceLength + 1);
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var tokenCount = 0;
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var offset = start;
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var balanceCloseType = 0;
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var balanceStart = 0;
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var balancePrev = 0;
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// https://drafts.csswg.org/css-syntax-3/#consume-token
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// § 4.3.1. Consume a token
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while (offset < sourceLength) {
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var code = source.charCodeAt(offset);
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var type = 0;
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balance[tokenCount] = sourceLength;
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switch (code < 0x80 ? INPUT_STREAM_CODE[code] : INPUT_STREAM_CODE_TYPE.NameStart) {
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// whitespace
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case INPUT_STREAM_CODE_TYPE.WhiteSpace:
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// Consume as much whitespace as possible. Return a <whitespace-token>.
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type = TYPE.WhiteSpace;
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offset = findWhiteSpaceEnd(source, offset + 1);
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break;
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// U+0022 QUOTATION MARK (")
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case 0x0022:
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// Consume a string token and return it.
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consumeStringToken();
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break;
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// U+0023 NUMBER SIGN (#)
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case 0x0023:
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// If the next input code point is a name code point or the next two input code points are a valid escape, then:
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if (isName(getCharCode(offset + 1)) || isValidEscape(getCharCode(offset + 1), getCharCode(offset + 2))) {
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// Create a <hash-token>.
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type = TYPE.Hash;
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// If the next 3 input code points would start an identifier, set the <hash-token>’s type flag to "id".
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// if (isIdentifierStart(getCharCode(offset + 1), getCharCode(offset + 2), getCharCode(offset + 3))) {
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// // TODO: set id flag
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// }
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// Consume a name, and set the <hash-token>’s value to the returned string.
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offset = consumeName(source, offset + 1);
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// Return the <hash-token>.
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} else {
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// Otherwise, return a <delim-token> with its value set to the current input code point.
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type = TYPE.Delim;
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offset++;
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}
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break;
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// U+0027 APOSTROPHE (')
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case 0x0027:
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// Consume a string token and return it.
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consumeStringToken();
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break;
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// U+0028 LEFT PARENTHESIS (()
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case 0x0028:
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// Return a <(-token>.
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type = TYPE.LeftParenthesis;
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offset++;
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break;
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// U+0029 RIGHT PARENTHESIS ())
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case 0x0029:
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// Return a <)-token>.
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type = TYPE.RightParenthesis;
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offset++;
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break;
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// U+002B PLUS SIGN (+)
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case 0x002B:
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// If the input stream starts with a number, ...
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if (isNumberStart(code, getCharCode(offset + 1), getCharCode(offset + 2))) {
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// ... reconsume the current input code point, consume a numeric token, and return it.
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consumeNumericToken();
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} else {
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// Otherwise, return a <delim-token> with its value set to the current input code point.
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type = TYPE.Delim;
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offset++;
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}
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break;
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// U+002C COMMA (,)
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case 0x002C:
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// Return a <comma-token>.
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type = TYPE.Comma;
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offset++;
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break;
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// U+002D HYPHEN-MINUS (-)
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case 0x002D:
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// If the input stream starts with a number, reconsume the current input code point, consume a numeric token, and return it.
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if (isNumberStart(code, getCharCode(offset + 1), getCharCode(offset + 2))) {
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consumeNumericToken();
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} else {
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// Otherwise, if the next 2 input code points are U+002D HYPHEN-MINUS U+003E GREATER-THAN SIGN (->), consume them and return a <CDC-token>.
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if (getCharCode(offset + 1) === HYPHENMINUS &&
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getCharCode(offset + 2) === GREATERTHANSIGN) {
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type = TYPE.CDC;
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offset = offset + 3;
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} else {
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// Otherwise, if the input stream starts with an identifier, ...
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if (isIdentifierStart(code, getCharCode(offset + 1), getCharCode(offset + 2))) {
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// ... reconsume the current input code point, consume an ident-like token, and return it.
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consumeIdentLikeToken();
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} else {
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// Otherwise, return a <delim-token> with its value set to the current input code point.
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type = TYPE.Delim;
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offset++;
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}
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}
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}
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break;
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// U+002E FULL STOP (.)
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case 0x002E:
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// If the input stream starts with a number, ...
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if (isNumberStart(code, getCharCode(offset + 1), getCharCode(offset + 2))) {
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// ... reconsume the current input code point, consume a numeric token, and return it.
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consumeNumericToken();
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} else {
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// Otherwise, return a <delim-token> with its value set to the current input code point.
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type = TYPE.Delim;
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offset++;
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}
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break;
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// U+002F SOLIDUS (/)
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case 0x002F:
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// If the next two input code point are U+002F SOLIDUS (/) followed by a U+002A ASTERISK (*),
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if (getCharCode(offset + 1) === ASTERISK) {
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// ... consume them and all following code points up to and including the first U+002A ASTERISK (*)
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// followed by a U+002F SOLIDUS (/), or up to an EOF code point.
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type = TYPE.Comment;
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offset = source.indexOf('*/', offset + 2) + 2;
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if (offset === 1) {
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offset = source.length;
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}
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} else {
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type = TYPE.Delim;
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offset++;
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}
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break;
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// U+003A COLON (:)
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case 0x003A:
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// Return a <colon-token>.
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type = TYPE.Colon;
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offset++;
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break;
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// U+003B SEMICOLON (;)
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case 0x003B:
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// Return a <semicolon-token>.
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type = TYPE.Semicolon;
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offset++;
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break;
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// U+003C LESS-THAN SIGN (<)
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case 0x003C:
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// If the next 3 input code points are U+0021 EXCLAMATION MARK U+002D HYPHEN-MINUS U+002D HYPHEN-MINUS (!--), ...
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if (getCharCode(offset + 1) === EXCLAMATIONMARK &&
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getCharCode(offset + 2) === HYPHENMINUS &&
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getCharCode(offset + 3) === HYPHENMINUS) {
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// ... consume them and return a <CDO-token>.
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type = TYPE.CDO;
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offset = offset + 4;
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} else {
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// Otherwise, return a <delim-token> with its value set to the current input code point.
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type = TYPE.Delim;
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offset++;
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}
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break;
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// U+0040 COMMERCIAL AT (@)
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case 0x0040:
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// If the next 3 input code points would start an identifier, ...
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if (isIdentifierStart(getCharCode(offset + 1), getCharCode(offset + 2), getCharCode(offset + 3))) {
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// ... consume a name, create an <at-keyword-token> with its value set to the returned value, and return it.
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type = TYPE.AtKeyword;
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offset = consumeName(source, offset + 1);
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} else {
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// Otherwise, return a <delim-token> with its value set to the current input code point.
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type = TYPE.Delim;
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offset++;
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}
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break;
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// U+005B LEFT SQUARE BRACKET ([)
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case 0x005B:
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// Return a <[-token>.
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type = TYPE.LeftSquareBracket;
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offset++;
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break;
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// U+005C REVERSE SOLIDUS (\)
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case 0x005C:
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// If the input stream starts with a valid escape, ...
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if (isValidEscape(code, getCharCode(offset + 1))) {
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// ... reconsume the current input code point, consume an ident-like token, and return it.
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consumeIdentLikeToken();
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} else {
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// Otherwise, this is a parse error. Return a <delim-token> with its value set to the current input code point.
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type = TYPE.Delim;
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offset++;
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}
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break;
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// U+005D RIGHT SQUARE BRACKET (])
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case 0x005D:
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// Return a <]-token>.
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type = TYPE.RightSquareBracket;
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offset++;
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break;
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// U+007B LEFT CURLY BRACKET ({)
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case 0x007B:
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// Return a <{-token>.
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type = TYPE.LeftCurlyBracket;
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offset++;
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break;
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// U+007D RIGHT CURLY BRACKET (})
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case 0x007D:
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// Return a <}-token>.
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type = TYPE.RightCurlyBracket;
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offset++;
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break;
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// digit
|
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case INPUT_STREAM_CODE_TYPE.Digit:
|
||
// Reconsume the current input code point, consume a numeric token, and return it.
|
||
consumeNumericToken();
|
||
break;
|
||
|
||
// name-start code point
|
||
case INPUT_STREAM_CODE_TYPE.NameStart:
|
||
// Reconsume the current input code point, consume an ident-like token, and return it.
|
||
consumeIdentLikeToken();
|
||
break;
|
||
|
||
// EOF
|
||
case INPUT_STREAM_CODE_TYPE.Eof:
|
||
// Return an <EOF-token>.
|
||
break;
|
||
|
||
// anything else
|
||
default:
|
||
// Return a <delim-token> with its value set to the current input code point.
|
||
type = TYPE.Delim;
|
||
offset++;
|
||
}
|
||
|
||
switch (type) {
|
||
case balanceCloseType:
|
||
balancePrev = balanceStart & OFFSET_MASK;
|
||
balanceStart = balance[balancePrev];
|
||
balanceCloseType = balanceStart >> TYPE_SHIFT;
|
||
balance[tokenCount] = balancePrev;
|
||
balance[balancePrev++] = tokenCount;
|
||
for (; balancePrev < tokenCount; balancePrev++) {
|
||
if (balance[balancePrev] === sourceLength) {
|
||
balance[balancePrev] = tokenCount;
|
||
}
|
||
}
|
||
break;
|
||
|
||
case TYPE.LeftParenthesis:
|
||
case TYPE.Function:
|
||
balance[tokenCount] = balanceStart;
|
||
balanceCloseType = TYPE.RightParenthesis;
|
||
balanceStart = (balanceCloseType << TYPE_SHIFT) | tokenCount;
|
||
break;
|
||
|
||
case TYPE.LeftSquareBracket:
|
||
balance[tokenCount] = balanceStart;
|
||
balanceCloseType = TYPE.RightSquareBracket;
|
||
balanceStart = (balanceCloseType << TYPE_SHIFT) | tokenCount;
|
||
break;
|
||
|
||
case TYPE.LeftCurlyBracket:
|
||
balance[tokenCount] = balanceStart;
|
||
balanceCloseType = TYPE.RightCurlyBracket;
|
||
balanceStart = (balanceCloseType << TYPE_SHIFT) | tokenCount;
|
||
break;
|
||
|
||
}
|
||
|
||
offsetAndType[tokenCount++] = (type << TYPE_SHIFT) | offset;
|
||
}
|
||
|
||
// finalize buffers
|
||
offsetAndType[tokenCount] = offset;
|
||
balance[tokenCount] = sourceLength;
|
||
balance[sourceLength] = sourceLength; // prevents false positive balance match with any token
|
||
while (balanceStart !== 0) {
|
||
balancePrev = balanceStart & OFFSET_MASK;
|
||
balanceStart = balance[balancePrev];
|
||
balance[balancePrev] = sourceLength;
|
||
}
|
||
|
||
// update stream
|
||
stream.source = source;
|
||
stream.firstCharOffset = start;
|
||
stream.offsetAndType = offsetAndType;
|
||
stream.tokenCount = tokenCount;
|
||
stream.balance = balance;
|
||
stream.reset();
|
||
stream.next();
|
||
|
||
return stream;
|
||
}
|
||
|
||
//
|
||
// tokenizer
|
||
//
|
||
|
||
// extend tokenizer with constants
|
||
Object.keys(constants).forEach(function(key) {
|
||
tokenize[key] = constants[key];
|
||
});
|
||
|
||
// extend tokenizer with static methods from utils
|
||
Object.keys(utils).forEach(function(key) {
|
||
tokenize[key] = utils[key];
|
||
});
|
||
|
||
module.exports = tokenize;
|