Compass/common/src/util/algos.ts

export function binarySearch(min: number, max: number, comparator: (x: number) => number) {
  let mid = 0
  let i = 0
  while (true) {
    mid = min + (max - min) / 2

    // Break once we've reached max precision.
    if (mid === min || mid === max) break

    const comparison = comparator(mid)
    if (comparison === 0) break
    else if (comparison > 0) {
      max = mid
    } else {
      min = mid
    }

    i++
    if (i > 100000) {
      throw new Error(
        'Binary search exceeded max iterations' + JSON.stringify({min, max, mid, i}, null, 2),
      )
    }
  }
  return mid
}