Algol60 passing integer element of array as parameter - error bad type

Question

I have following problem.

When I try to run the code with arun file.obj (I have compiled with algol.exe file)

BEGIN

    INTEGER PROCEDURE fun(tab,index,lower,upper);
        INTEGER tab,index,lower,upper;
    BEGIN
        INTEGER t;
        text (1, "Start");
        t := 0;

        FOR index := lower STEP 1 UNTIL upper DO
            t := t + tab;

        fun := t;

    END;

    INTEGER ARRAY t[1:10];
    INTEGER i,result,lower,upper;

    lower := 1;
    upper := 10;

    FOR i := 1 STEP 1 UNTIL 10 DO
        t[i] := i;

    i := 1;

    result := fun(t[i],i,lower,upper);
END FINISH;

I am still getting error:

ERROR 3
ADD PBASE PROC LOC
07D4 0886 1    13
083A 0842 0    115

The compiler I use is "The Rogalgol Algol60" product of RHA (Minisystems) Ltd.

Error 3 means "3 Procedure called where the actual and the formal parameter types do not match."

But I do not understand why. The reason of error is t[i] (If I change to i - it is ok).

Someone knows what I am doing wrongly?

I compile the code on the dosbox (linux)

Answer 1

Problem is that the index of the integer array that you're passing to your procedure isn't the same as the integer that he's expecting. I can't remember what an integer array is full of, but I guess it isn't integers... Have to admit I never use them, but can't remember why. Possibly because of limitations like this. I stick to Real arrays and EBCDIC ones.

You can almost certainly fix it by defining a new integer, j; inserting "j := t[i];" before your invocation of 'fun'; then invoking 'fun' with 'j' rather than t[i].

BTW you may want to make the array (and the 'for' loop) zero-relative. ALGOL is mostly zero-relative and I think it may save memory if you go with the flow.

Let me know if this helps....