logging a function's argument

[Wes Loewer]

With the 50g, it was possible to have a function with the side effect of logging the argument by appending it to a list. Say something like this.

Code:


XARG
<< ->  X
  << 'XLST' X STO+ X >> 
>>

where 'XLST' starts out as an empty list.

My motivation for such a function was to explore certain algorithms such as numeric solving and numeric integration. Afterwards, I could look at the 'XLST' to see what the algorithm did. It worked like a charm.

My attempts for doing the same with the Prime have been less successful. I tried

Code:

EXPORT XARG(x)
BEGIN
 L1:=CONCAT(L1,x);
 RETURN x;
END;

and

Code:

#cas
xarg(x):=
BEGIN
 L1:=CONCAT(L1,x);
 RETURN x;
END;
#end

These work fine when executed directly from the command line. But when used within fsolve() or int(), neither works as hoped.

Any ideas on how to make this work?