105 lines
2.9 KiB
JavaScript
105 lines
2.9 KiB
JavaScript
var hasOwnProperty = Object.prototype.hasOwnProperty;
|
|
var keywords = Object.create(null);
|
|
var properties = Object.create(null);
|
|
var HYPHENMINUS = 45; // '-'.charCodeAt()
|
|
|
|
function isCustomProperty(str, offset) {
|
|
offset = offset || 0;
|
|
|
|
return str.length - offset >= 2 &&
|
|
str.charCodeAt(offset) === HYPHENMINUS &&
|
|
str.charCodeAt(offset + 1) === HYPHENMINUS;
|
|
}
|
|
|
|
function getVendorPrefix(str, offset) {
|
|
offset = offset || 0;
|
|
|
|
// verdor prefix should be at least 3 chars length
|
|
if (str.length - offset >= 3) {
|
|
// vendor prefix starts with hyper minus following non-hyper minus
|
|
if (str.charCodeAt(offset) === HYPHENMINUS &&
|
|
str.charCodeAt(offset + 1) !== HYPHENMINUS) {
|
|
// vendor prefix should contain a hyper minus at the ending
|
|
var secondDashIndex = str.indexOf('-', offset + 2);
|
|
|
|
if (secondDashIndex !== -1) {
|
|
return str.substring(offset, secondDashIndex + 1);
|
|
}
|
|
}
|
|
}
|
|
|
|
return '';
|
|
}
|
|
|
|
function getKeywordDescriptor(keyword) {
|
|
if (hasOwnProperty.call(keywords, keyword)) {
|
|
return keywords[keyword];
|
|
}
|
|
|
|
var name = keyword.toLowerCase();
|
|
|
|
if (hasOwnProperty.call(keywords, name)) {
|
|
return keywords[keyword] = keywords[name];
|
|
}
|
|
|
|
var custom = isCustomProperty(name, 0);
|
|
var vendor = !custom ? getVendorPrefix(name, 0) : '';
|
|
|
|
return keywords[keyword] = Object.freeze({
|
|
basename: name.substr(vendor.length),
|
|
name: name,
|
|
vendor: vendor,
|
|
prefix: vendor,
|
|
custom: custom
|
|
});
|
|
}
|
|
|
|
function getPropertyDescriptor(property) {
|
|
if (hasOwnProperty.call(properties, property)) {
|
|
return properties[property];
|
|
}
|
|
|
|
var name = property;
|
|
var hack = property[0];
|
|
|
|
if (hack === '/') {
|
|
hack = property[1] === '/' ? '//' : '/';
|
|
} else if (hack !== '_' &&
|
|
hack !== '*' &&
|
|
hack !== '$' &&
|
|
hack !== '#' &&
|
|
hack !== '+' &&
|
|
hack !== '&') {
|
|
hack = '';
|
|
}
|
|
|
|
var custom = isCustomProperty(name, hack.length);
|
|
|
|
// re-use result when possible (the same as for lower case)
|
|
if (!custom) {
|
|
name = name.toLowerCase();
|
|
if (hasOwnProperty.call(properties, name)) {
|
|
return properties[property] = properties[name];
|
|
}
|
|
}
|
|
|
|
var vendor = !custom ? getVendorPrefix(name, hack.length) : '';
|
|
var prefix = name.substr(0, hack.length + vendor.length);
|
|
|
|
return properties[property] = Object.freeze({
|
|
basename: name.substr(prefix.length),
|
|
name: name.substr(hack.length),
|
|
hack: hack,
|
|
vendor: vendor,
|
|
prefix: prefix,
|
|
custom: custom
|
|
});
|
|
}
|
|
|
|
module.exports = {
|
|
keyword: getKeywordDescriptor,
|
|
property: getPropertyDescriptor,
|
|
isCustomProperty: isCustomProperty,
|
|
vendorPrefix: getVendorPrefix
|
|
};
|