Standard ML code

Write a function countInList which takes a value and a list and returns the number of occurrences of that value in the input list. The type of your function should be ''a list -> ''a -> int. Examples:

> countInList ["3","5","5","-","4","5","1"] "5"

3

> countInList [] "5"

0

> countInList [true, false, false, false, true, true, true] true

4

> countInList [[],[1,2],[3,2],[5,6,7],[8],[]] []

2