Kata

Given a string, your task is to count the number and length of arrow symbols in that string and return an int using the following rules:

• The string will only contain the characters ., -, =, <, >.
• An arrow must start with either < or >.
• Arrows are scored based on their length and direction, for example:
  • (Left-facing arrows are scored as negative, while Right-facing arrows are positive)
  • > is scored as 1
  • -> is scored as 2
  • < is scored as -1
  • <- is scored as -2
• An arrow's tail (if it has one) must be entirely made up of either - or =. You cannot mix.
• So, --> would be a valid arrow of length 3, but =-> would only count -> as a part of the arrow.
• Additionally, arrows with a tail of = are scored twice as high as arrows with a tail of -, for example:
  • --> is scored as 3
  • ==> is scored as 6
  • <= is scored as -4

• Double-sided arrows, like <-> or <===> are counted as 0.
• . is an empty character and cannot be the tail of an arrow.

  Examples

    arrow_search('>.') # 1
    arrow_search('<--..') # -3
    arrow_search('><=><--') # -2
    arrow_search('>===>->') # 11