CASE and PIECEWISE in CAS programs

[Alberto Candel]

Hi,
I wrote a CAS program that contains the CASE command, like this

Code:

(x)->BEGIN
LOCAL k,s:=0;
CASES
IF x=0 THEN RETURN(s) END;
IF x=1 THEN RETURN(s+1) END;
DEFAULT
FOR k FROM 2 TO x DO
s:=s+1/(k^2-k);
END;
END;
RETURN(s);
END;

The "Check" soft-key returns No errors in the program. So I exit the program editor and confirm that the program works OK. When I return to this program for further editing, I find that the Prime has rewritten it like so:

Code:

(x)->BEGIN
 LOCAL k,s;
    s:=0;
    piecewise([x=0, RETURN(s), x=1, RETURN(s+1), FOR k FROM 2 TO x DO s:=s+1/(k^2-k); END;]);
    RETURN(s);
END;

So the CASE has been changed to piecewise. The program also runs OK, but no the "Check" soft-key returns
Error:Syntax Error and upon exiting the program editor (Shift+Programs), the Prime displays Syntax error in program line 3

I wonder if anyone knows what is going on. Thank you.

[parisse]

There is an extra ; after END before ] in piecewise (and [] should not be there).
I'm going to fix piecewise printing on the Prime.

[Alberto Candel]

(07-22-2014 09:50 AM)parisse Wrote:  There is an extra ; after END before ] in piecewise (and [] should not be there).
I'm going to fix piecewise printing on the Prime.

yes, removing the extra ; after END shows no errors. But the prime will put the ; back, and it will move the closing parenthesis from the two RETURN() to the end. This renders the program unusable, as there is no way to correct it; it has to be rewritten with CASE.

[parisse]

If you edit your CAS program in the programming editor, it will be stored as is (not parsed and re-printed), and you can modify it without any problem.

[Alberto Candel]

(07-22-2014 04:13 PM)parisse Wrote:  If you edit your CAS program in the programming editor, it will be stored as is (not parsed and re-printed), and you can modify it without any problem.

I am pretty sure I was doing Shift+Program, then select, then Edit. I also had the Algebraic entry in the Home settings (it appears that piecewise behaves differently with Textbook entry).