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//Const
const NOAH_ARK_CAPACITY = 3;
export var EntryType;
(function (EntryType) {
EntryType[EntryType["Marker"] = 0] = "Marker";
EntryType[EntryType["Element"] = 1] = "Element";
})(EntryType = EntryType || (EntryType = {}));
const MARKER = { type: EntryType.Marker };
//List of formatting elements
export class FormattingElementList {
constructor(treeAdapter) {
this.treeAdapter = treeAdapter;
this.entries = [];
this.bookmark = null;
}
//Noah Ark's condition
//OPTIMIZATION: at first we try to find possible candidates for exclusion using
//lightweight heuristics without thorough attributes check.
_getNoahArkConditionCandidates(newElement, neAttrs) {
const candidates = [];
const neAttrsLength = neAttrs.length;
const neTagName = this.treeAdapter.getTagName(newElement);
const neNamespaceURI = this.treeAdapter.getNamespaceURI(newElement);
for (let i = 0; i < this.entries.length; i++) {
const entry = this.entries[i];
if (entry.type === EntryType.Marker) {
break;
}
const { element } = entry;
if (this.treeAdapter.getTagName(element) === neTagName &&
this.treeAdapter.getNamespaceURI(element) === neNamespaceURI) {
const elementAttrs = this.treeAdapter.getAttrList(element);
if (elementAttrs.length === neAttrsLength) {
candidates.push({ idx: i, attrs: elementAttrs });
}
}
}
return candidates;
}
_ensureNoahArkCondition(newElement) {
if (this.entries.length < NOAH_ARK_CAPACITY)
return;
const neAttrs = this.treeAdapter.getAttrList(newElement);
const candidates = this._getNoahArkConditionCandidates(newElement, neAttrs);
if (candidates.length < NOAH_ARK_CAPACITY)
return;
//NOTE: build attrs map for the new element, so we can perform fast lookups
const neAttrsMap = new Map(neAttrs.map((neAttr) => [neAttr.name, neAttr.value]));
let validCandidates = 0;
//NOTE: remove bottommost candidates, until Noah's Ark condition will not be met
for (let i = 0; i < candidates.length; i++) {
const candidate = candidates[i];
// We know that `candidate.attrs.length === neAttrs.length`
if (candidate.attrs.every((cAttr) => neAttrsMap.get(cAttr.name) === cAttr.value)) {
validCandidates += 1;
if (validCandidates >= NOAH_ARK_CAPACITY) {
this.entries.splice(candidate.idx, 1);
}
}
}
}
//Mutations
insertMarker() {
this.entries.unshift(MARKER);
}
pushElement(element, token) {
this._ensureNoahArkCondition(element);
this.entries.unshift({
type: EntryType.Element,
element,
token,
});
}
insertElementAfterBookmark(element, token) {
const bookmarkIdx = this.entries.indexOf(this.bookmark);
this.entries.splice(bookmarkIdx, 0, {
type: EntryType.Element,
element,
token,
});
}
removeEntry(entry) {
const entryIndex = this.entries.indexOf(entry);
if (entryIndex >= 0) {
this.entries.splice(entryIndex, 1);
}
}
/**
* Clears the list of formatting elements up to the last marker.
*
* @see https://html.spec.whatwg.org/multipage/parsing.html#clear-the-list-of-active-formatting-elements-up-to-the-last-marker
*/
clearToLastMarker() {
const markerIdx = this.entries.indexOf(MARKER);
if (markerIdx >= 0) {
this.entries.splice(0, markerIdx + 1);
}
else {
this.entries.length = 0;
}
}
//Search
getElementEntryInScopeWithTagName(tagName) {
const entry = this.entries.find((entry) => entry.type === EntryType.Marker || this.treeAdapter.getTagName(entry.element) === tagName);
return entry && entry.type === EntryType.Element ? entry : null;
}
getElementEntry(element) {
return this.entries.find((entry) => entry.type === EntryType.Element && entry.element === element);
}
}
//# sourceMappingURL=formatting-element-list.js.map |