[PPL-devel] x still a variable after a successful call to c2p_list(x)?

[Roberto Bagnara]

Dear all,

I am sure I am missing something but I don't know what.
After a quite long debugging session, I have the following
fragment in my C++ code:

    prolog_term x = p2p_new();
    if (is_var(x) == FALSE)
      abort(); // This statement does not get executed.
    if (c2p_list(x) == FALSE)
      abort(); // This statement does not get executed.
    // Hey, how can `x' still be a variable?
    if (is_var(x) == TRUE)
      abort(); // This statement IS executed.

`x' is initialized to a fresh variable (so that the first
call to abort() is not executed), then the call to c2p_list()
is successful (so that the second call to abort() is not executed),
but afterwards `x' is still bound to a variable (and the third
call to abort() is executed).
Any idea why that happens?
All the best

      Roberto



P.S.  I am using XSB 2.5

$ xsb
[xsb_configuration loaded]
[sysinitrc loaded]
[packaging loaded]

XSB Version 2.5 (Okocim) of March 11, 2002
[i686-pc-linux-gnu; mode: optimal; engine: slg-wam; gc: indirection; scheduling: local]

| ?-

-- 
Prof. Roberto Bagnara
Computer Science Group
Department of Mathematics, University of Parma, Italy
http://www.cs.unipr.it/~bagnara/
mailto:bagnara at cs.unipr.it