/ CASE STUDY
/ The Source Language
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.
(* read integers and write *) (* until a nonpositive number is read *) READ (i); WHILE 0 < i DO WRITE (i); READ (i) END