folding cursors all day

cursor.kt

inline fun <T> Cursor.fold(zero: T, f: (Cursor, T) -> T): T =
    if (moveToFirst()) {
      moveToPrevious()
      var accum = zero
      while (moveToNext()) {
        accum = f(this, accum)
      }
      accum
    } else zero

inline fun <T> Cursor.forEachRow(f: (Cursor) -> T): Unit =
    fold(Unit) { c, x -> f(c) }

inline fun <T> Cursor.map(f: (Cursor) -> T): List<T> =
    fold(ArrayList<T>(count)) { c, list -> list.apply { add(f(c)) } }