Kaleidoscope: Extending the Language: Control Flow

Kaleidoscope also supports the "for" loop construct, which is used to iterate over a range of values. Here is an example of a "for" loop:

def print_range(start, end, step)
  for i = start, i < end, step in
    print(i)

This code defines a function called "print_range" that takes three arguments, start, end, and step. Inside the function, a "for" loop is used to iterate over the range of values from "start" to "end" with a step size of "step". During each iteration, the current value of "i" is printed.

Kaleidoscope also supports pattern matching, which is a powerful feature for working with complex data structures. Here is an example of a function that uses pattern matching to extract the first element of a list:

def first_elem(list)
  case list
  of x :: xs => x
  | _ => error("Empty list")

This code defines a function called "first_elem" that takes a list as an argument. Inside the function, a "case" statement is used to match against the list. If the list is non-empty, the first element is extracted and returned. Otherwise, an error is raised.

Finally, Kaleidoscope supports error handling using the "error" function. When an error is raised, the program will terminate and print an error message.