TypeScript Options.liftN方法代碼示例

const rngSetContent = (rng: Range, fragment: DocumentFragment): void => {
  const firstChild = Option.from(fragment.firstChild).map(Element.fromDom);
  const lastChild = Option.from(fragment.lastChild).map(Element.fromDom);

  rng.deleteContents();
  rng.insertNode(fragment);

  const prevText = firstChild.bind(Traverse.prevSibling).filter(Node.isText).bind(removeEmpty);
  const nextText = lastChild.bind(Traverse.nextSibling).filter(Node.isText).bind(removeEmpty);

  // Join start
  Options.liftN([prevText, firstChild.filter(Node.isText)], (prev: Element, start: Element) => {
    prependData(start.dom(), prev.dom().data);
    Remove.remove(prev);
  });

  // Join end
  Options.liftN([nextText, lastChild.filter(Node.isText)], (next: Element, end: Element) => {
    const oldLength = end.dom().length;
    end.dom().appendData(next.dom().data);
    rng.setEnd(end.dom(), oldLength);
    Remove.remove(next);
  });

  rng.collapse(false);
};

const deleteNormalized = function (elm, afterDeletePosOpt) {
  return Options.liftN([Traverse.prevSibling(elm), Traverse.nextSibling(elm), afterDeletePosOpt], function (prev, next, afterDeletePos) {
    let offset;
    const prevNode = prev.dom();
    const nextNode = next.dom();

    if (NodeType.isText(prevNode) && NodeType.isText(nextNode)) {
      offset = prevNode.data.length;
      prevNode.appendData(nextNode.data);
      Remove.remove(next);
      Remove.remove(elm);
      if (afterDeletePos.container() === nextNode) {
        return new CaretPosition(prevNode, offset);
      } else {
        return afterDeletePos;
      }
    } else {
      Remove.remove(elm);
      return afterDeletePos;
    }
  }).orThunk(function () {
    Remove.remove(elm);
    return afterDeletePosOpt;
  });
};

 (lastPos) => {
   return Options.liftN([Arr.head(lastPos.getClientRects()), Arr.head(newPos.getClientRects())], (lastRect, newRect) => {
     const lastDist = Math.abs(x - lastRect.left);
     const newDist = Math.abs(x - newRect.left);
     return newDist <= lastDist ? newPos : lastPos;
   }).or(acc);
 }

const getCellRng = function (rng, isRoot) {
  return Options.liftN([ // get start and end cell
    getClosestCell(rng.startContainer, isRoot),
    getClosestCell(rng.endContainer, isRoot)
  ], tableCellRng)
    .filter(isExpandedCellRng);
};

const hasAllContentsSelected = function (elm, rng) {
  return Options.liftN([getStartNode(rng), getEndNode(rng)], function (startNode, endNode) {
    const start = Arr.find(getFirstChildren(elm), Fun.curry(Compare.eq, startNode));
    const end = Arr.find(getLastChildren(elm), Fun.curry(Compare.eq, endNode));
    return start.isSome() && end.isSome();
  }).getOr(false);
};

const getSelectedCells = (tableSelection) => {
  return Options.liftN([
    getCellIndex(tableSelection.cells(), tableSelection.rng().start()),
    getCellIndex(tableSelection.cells(), tableSelection.rng().end())
  ], (startIndex, endIndex) => {
    return tableSelection.cells().slice(startIndex, endIndex + 1);
  });
};

const getItemSelection = (editor: Editor): Option<ItemSelection> => {
  const selectedListItems = Arr.map(Selection.getSelectedListItems(editor), Element.fromDom);

  return Options.liftN([
    Arr.find(selectedListItems, Fun.not(hasFirstChildList)),
    Arr.find(Arr.reverse(selectedListItems), Fun.not(hasFirstChildList))
  ], (start, end) => ({ start, end }));
};

export const makeRatioConverter = (currentFieldText: string, otherFieldText: string): SizeConversion => {
  const cValue = parseSize(currentFieldText).toOption();
  const oValue = parseSize(otherFieldText).toOption();
  return Options.liftN([cValue, oValue], (cSize: Size, oSize: Size) => {
    return convertUnit(cSize, oSize.unit).map((val) => oSize.value / val).map(
      (r) => ratioSizeConversion(r, oSize.unit)
    ).getOr(noSizeConversion);
  }).getOr(noSizeConversion);
};

const getCellRng = (rng: Range, isRoot) => {
  const startCell = getClosestCell(rng.startContainer, isRoot);
  const endCell = getClosestCell(rng.endContainer, isRoot);

  return Options.liftN([startCell, endCell], tableCellRng)
    .filter(isExpandedCellRng)
    .filter((cellRng) => isWithinSameTable(isRoot, cellRng))
    .orThunk(() => partialSelection(isRoot, rng));
};

const writeDeep = (scope: Document, outline: Section[], entry: Entry): Section[] => {
  const newSections = createJoinedSections(scope, entry.depth - outline.length, entry.listType);
  populateSections(newSections, entry);

  Options.liftN([
    Arr.last(outline),
    Arr.head(newSections)
  ], joinSections);
  return outline.concat(newSections);
};