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Question: Persistent variable

Question:Persistent variable

Pascal4QM 478 Maple 2017
procedure programming
October 22 2017
0

I would like to implement a persistent variable inside a procedure. That is:

  1. A variable that is first initialized if it does not exist.
  2. Its value is kept over multiple call of the procedure where it is defined.

As an example, the following procedure counts the number of times it is called:

restart;
CountProc := proc () 
     global m; 
     if `not`(m::integer) then      
          m := 0;
     end if; 
     m := m+1; 
     return m;
end proc;

CountProc(); CountProc(); CountProc();
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That’s almost what I need, except the variable "m" should be local instead of global. How to do that?
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