as_string function:
return the string if the argument is a string, nothing if it's not.
Examples:
- running:
(as_string "text")will give:"text"
- running:
(as_string 312)will return nothing
as_string function:return the string if the argument is a string, nothing if it's not.
(as_string "text")
will give: "text"(as_string 312)
will return nothing