lepu-test-platform-web/node_modules/css-tree/lib/lexer/generic-an-plus-b.js

237 lines
6.6 KiB
JavaScript

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;
};