(string-head string integer) -> string
Returns the first x characters of the given string, where x is the given integer.
Examples:
>> (string-head "Eric Jordan" 5) :: "Eric " >> (string-head "Eric Jordan" 0) :: "" >> (string-head "Eric Jordan" 1) :: "E" >> (string-head "Eric Jordan" 15) ERROR: bad-args -- length must be not exceed the string length TRACE: (<program>) (repl) (string-head "Eric Jordan" 15)