Count : Counting Items

Count has one default input and three outputs :

• "what" : a value.
• first output : triggers the increment of the counter if the input is non nil, and returns its current value.
• second output : returns the current state of the counter.
• third output : resets the value of the counter to zero.

1. Listloop returns each element of the list successively to count. These elements are non nil values.

2. The first output of count adds 1 every time listloop returns an element.

3. Once the enumeration of listloop is over, the final state of count is returned by Finally.

1. Listloop enumerates the elements of a list.

2. The stringp predicate returns true every time it evaluates a string.

3. At each step of the loop, the first output of count is evaluated :

   • if it gets a non nil value from stringp, it increments the value of the counter
   • if it gets "nil", the value doesn't change.

4. The results returned by stringp and counter are gathered in a list and printed.

5. The total number of strings, that is, the final state of counter is returned by Finally.