/Users/garethloy/Musimathics/Musimat1.2/MusimatTutorial/B0119.cpp File Reference

#include "MusimatTutorial.h"

Go to the source code of this file.

Functions
	MusimatTutorialSection (B0119)
Integer	euclid (Integer m, Integer n)
Void	testEuclid ()

---

Function Documentation

Integer euclid	(	Integer	m,
		Integer	n
	)

Definition at line 16 of file B0119.cpp.

                                     {
        Repeat { 
                Integer r = Mod(m, n); 
                If (r == 0)  
                        Return(n);
                Else  { 
                        m = n; 
                        n = r; 
                }
        }
}

MusimatTutorialSection

(

B0119

)

Definition at line 2 of file B0119.cpp.

References testEuclid().

                              {
        Print("*** B.1.19 User-Defined Functions ***");
        /*****************************************************************************
         
         B.1.19 User-Defined Functions
         
         Musimat, like most programming languages, allows users to define their own functions. Take 
         Euclid's method, for example. To define it, we must state how the input variables m and n receive 
         their inputs, and determine what happens to the result when the method halts. We can define a func-
         tion named euclid() in Musimat as follows:
         *****************************************************************************/
        testEuclid(); // The tutorial continues in this function (step into the function).
}

Void testEuclid

(

)

Definition at line 28 of file B0119.cpp.

References euclid(), and x.

                  {
        /*****************************************************************************
         The function euclid() is declared to be of type Integer because it will return an Integer result. 
         
         Note that Return(n) has been substituted for the Halt(n) function shown previously. Instead 
         of halting execution altogether, the Return(n) statement only exits the current function, carrying 
         with it the value of its argument back to the context that invoked it. The program can then continue 
         executing from there, if there are statements following its invocation. Here's an example of invok-
         ing the euclid() function:
         *****************************************************************************/                                                                                 
        
        Integer x = euclid(91, 416);
        Print(x);
        
        /*****************************************************************************
         which will print 13. If we had used Halt() in euclid(), we'd never reach the Print statement 
         because the program would stop.
         
         Here's another way to compute the same thing:
         *****************************************************************************/
        
        Print(euclid(91, 416));
        
        /*****************************************************************************
         This way we can eliminate the "middleman" variable x, which only existed to carry the value from 
         the euclid() function to the Print() function. In this example, the call to the euclid() func-
         tion is nested within the Print() function. Musimat invokes the nested function first, and the 
         value that euclid() returns is supplied automatically as an argument to the enclosing function, 
         Print(). Functions can be nested to an arbitrary extent. The most deeply nested function is 
         always called first.
         
         *****************************************************************************/
}