fromRanges.ts

  function fromSortedRanges(ranges: ReadonlyArray<RangeCov>): RangeTree | undefined {
    let root: RangeTree | undefined;
    const stack: RangeTree[] = [];
    for (const range of ranges) {
      const node: RangeTree = new RangeTree(range.startOffset, range.endOffset, range.count, [], 0, 0);
      if (root === undefined) {
        root = node;
        stack.push(node);
        continue;
      }
      let top: RangeTree;
      while (true) {
        top = stack[stack.length - 1];
        // assert: `top !== undefined` (the ranges are sorted)
        if (range.startOffset < top.end) {
          break;
        } else {
          stack.pop();
        }
      }
      top.children.push(node);
      stack.push(node);
    }
    return root;
  }