Input and Output

Input and output of values of simple types is achieved by the standard procedures READ and WRITE.

The procedure READ takes one actual parameter which must be a variable of a simple type. It reads a value of the corresponding type from the standard input and assigns it to that variable.

The procedure WRITE takes one actual parameter which must be an expression with a simple type. It writes the value of that expression onto the standard output.

Example:

(* read integers and write            *)
(* until a nonpositive number is read *)
READ (i);
WHILE 0 < i DO
  WRITE (i); READ (i)
END