Function binSearch

packages/react-devtools-shared/src/hooks/getHookNameForLocation.js:87–125

(
  location: Position,
  items: T[],
  compare: (
    location: Position,
    items: T[],
    index: number,
  ) => {index: number | null, direction: number},
)

}

function binSearch<T>(
  location: Position,
  items: T[],
  compare: (
    location: Position,
    items: T[],
    index: number,
  ) => {index: number | null, direction: number},
): T | null {
  let count = items.length;
  let index = 0;
  let firstElementIndex = 0;
  let step;

  while (count > 0) {
    index = firstElementIndex;
    step = Math.floor(count / 2);
    index += step;

    const comparison = compare(location, items, index);
    if (comparison.direction === 0) {
      if (comparison.index == null) {
        throw new Error('Expected an index when matching element is found.');
      }
      firstElementIndex = comparison.index;
      break;
    }

    if (comparison.direction > 0) {
      index++;
      firstElementIndex = index;
      count -= step + 1;
    } else {
      count = step;
    }
  }

  return firstElementIndex != null ? items[firstElementIndex] : null;
}

/**
 * Compares the target line location to the current location