| var isDigit = require('../tokenizer').isDigit; |
| var cmpChar = require('../tokenizer').cmpChar; |
| var TYPE = require('../tokenizer').TYPE; |
| |
| var DELIM = TYPE.Delim; |
| var WHITESPACE = TYPE.WhiteSpace; |
| var COMMENT = TYPE.Comment; |
| 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 N = 0x006E; // U+006E LATIN SMALL LETTER N (n) |
| var DISALLOW_SIGN = true; |
| var ALLOW_SIGN = false; |
| |
| function isDelim(token, code) { |
| return token !== null && token.type === DELIM && token.value.charCodeAt(0) === code; |
| } |
| |
| function skipSC(token, offset, getNextToken) { |
| while (token !== null && (token.type === WHITESPACE || token.type === COMMENT)) { |
| token = getNextToken(++offset); |
| } |
| |
| return offset; |
| } |
| |
| function checkInteger(token, valueOffset, disallowSign, offset) { |
| if (!token) { |
| return 0; |
| } |
| |
| var code = token.value.charCodeAt(valueOffset); |
| |
| if (code === PLUSSIGN || code === HYPHENMINUS) { |
| if (disallowSign) { |
| // Number sign is not allowed |
| return 0; |
| } |
| valueOffset++; |
| } |
| |
| for (; valueOffset < token.value.length; valueOffset++) { |
| if (!isDigit(token.value.charCodeAt(valueOffset))) { |
| // Integer is expected |
| return 0; |
| } |
| } |
| |
| return offset + 1; |
| } |
| |
| // ... <signed-integer> |
| // ... ['+' | '-'] <signless-integer> |
| function consumeB(token, offset_, getNextToken) { |
| var sign = false; |
| var offset = skipSC(token, offset_, getNextToken); |
| |
| token = getNextToken(offset); |
| |
| if (token === null) { |
| return offset_; |
| } |
| |
| if (token.type !== NUMBER) { |
| if (isDelim(token, PLUSSIGN) || isDelim(token, HYPHENMINUS)) { |
| sign = true; |
| offset = skipSC(getNextToken(++offset), offset, getNextToken); |
| token = getNextToken(offset); |
| |
| if (token === null && token.type !== NUMBER) { |
| return 0; |
| } |
| } else { |
| return offset_; |
| } |
| } |
| |
| if (!sign) { |
| var code = token.value.charCodeAt(0); |
| if (code !== PLUSSIGN && code !== HYPHENMINUS) { |
| // Number sign is expected |
| return 0; |
| } |
| } |
| |
| return checkInteger(token, sign ? 0 : 1, sign, offset); |
| } |
| |
| // An+B microsyntax https://www.w3.org/TR/css-syntax-3/#anb |
| module.exports = function anPlusB(token, getNextToken) { |
| /* eslint-disable brace-style*/ |
| var offset = 0; |
| |
| if (!token) { |
| return 0; |
| } |
| |
| // <integer> |
| if (token.type === NUMBER) { |
| return checkInteger(token, 0, ALLOW_SIGN, offset); // b |
| } |
| |
| // -n |
| // -n <signed-integer> |
| // -n ['+' | '-'] <signless-integer> |
| // -n- <signless-integer> |
| // <dashndashdigit-ident> |
| else if (token.type === IDENT && token.value.charCodeAt(0) === HYPHENMINUS) { |
| // expect 1st char is N |
| if (!cmpChar(token.value, 1, N)) { |
| return 0; |
| } |
| |
| switch (token.value.length) { |
| // -n |
| // -n <signed-integer> |
| // -n ['+' | '-'] <signless-integer> |
| case 2: |
| return consumeB(getNextToken(++offset), offset, getNextToken); |
| |
| // -n- <signless-integer> |
| case 3: |
| if (token.value.charCodeAt(2) !== HYPHENMINUS) { |
| return 0; |
| } |
| |
| offset = skipSC(getNextToken(++offset), offset, getNextToken); |
| token = getNextToken(offset); |
| |
| return checkInteger(token, 0, DISALLOW_SIGN, offset); |
| |
| // <dashndashdigit-ident> |
| default: |
| if (token.value.charCodeAt(2) !== HYPHENMINUS) { |
| return 0; |
| } |
| |
| return checkInteger(token, 3, DISALLOW_SIGN, offset); |
| } |
| } |
| |
| // '+'? n |
| // '+'? n <signed-integer> |
| // '+'? n ['+' | '-'] <signless-integer> |
| // '+'? n- <signless-integer> |
| // '+'? <ndashdigit-ident> |
| else if (token.type === IDENT || (isDelim(token, PLUSSIGN) && getNextToken(offset + 1).type === IDENT)) { |
| // just ignore a plus |
| if (token.type !== IDENT) { |
| token = getNextToken(++offset); |
| } |
| |
| if (token === null || !cmpChar(token.value, 0, N)) { |
| return 0; |
| } |
| |
| switch (token.value.length) { |
| // '+'? n |
| // '+'? n <signed-integer> |
| // '+'? n ['+' | '-'] <signless-integer> |
| case 1: |
| return consumeB(getNextToken(++offset), offset, getNextToken); |
| |
| // '+'? n- <signless-integer> |
| case 2: |
| if (token.value.charCodeAt(1) !== HYPHENMINUS) { |
| return 0; |
| } |
| |
| offset = skipSC(getNextToken(++offset), offset, getNextToken); |
| token = getNextToken(offset); |
| |
| return checkInteger(token, 0, DISALLOW_SIGN, offset); |
| |
| // '+'? <ndashdigit-ident> |
| default: |
| if (token.value.charCodeAt(1) !== HYPHENMINUS) { |
| return 0; |
| } |
| |
| return checkInteger(token, 2, DISALLOW_SIGN, offset); |
| } |
| } |
| |
| // <ndashdigit-dimension> |
| // <ndash-dimension> <signless-integer> |
| // <n-dimension> |
| // <n-dimension> <signed-integer> |
| // <n-dimension> ['+' | '-'] <signless-integer> |
| else if (token.type === DIMENSION) { |
| var code = token.value.charCodeAt(0); |
| var sign = code === PLUSSIGN || code === HYPHENMINUS ? 1 : 0; |
| |
| for (var i = sign; i < token.value.length; i++) { |
| if (!isDigit(token.value.charCodeAt(i))) { |
| break; |
| } |
| } |
| |
| if (i === sign) { |
| // Integer is expected |
| return 0; |
| } |
| |
| if (!cmpChar(token.value, i, N)) { |
| return 0; |
| } |
| |
| // <n-dimension> |
| // <n-dimension> <signed-integer> |
| // <n-dimension> ['+' | '-'] <signless-integer> |
| if (i + 1 === token.value.length) { |
| return consumeB(getNextToken(++offset), offset, getNextToken); |
| } else { |
| if (token.value.charCodeAt(i + 1) !== HYPHENMINUS) { |
| return 0; |
| } |
| |
| // <ndash-dimension> <signless-integer> |
| if (i + 2 === token.value.length) { |
| offset = skipSC(getNextToken(++offset), offset, getNextToken); |
| token = getNextToken(offset); |
| |
| return checkInteger(token, 0, DISALLOW_SIGN, offset); |
| } |
| // <ndashdigit-dimension> |
| else { |
| return checkInteger(token, i + 2, DISALLOW_SIGN, offset); |
| } |
| } |
| } |
| |
| return 0; |
| }; |