Hello, It seems to be an issue in the top-level when loading the following program (say, p.pl):
:- initialization(main).
main :- repeat, read(X), X==stop.
By submitting 'ensure_loaded(p)' the program does not stop when reading the term 'stop'. However, the very same program without the initialization directive does return to the top-level when explicitly called with the goal 'main'. Is this a bug or a feature? This execution corresponds to the Windows stable version 1.10p5 running on Windows XP SP3. By the way, when will the next stable version be released? All the best, Fernando Sáenz
2010/11/12 Fernando Sáenz Pérez <fernan(a)sip.ucm.es>:
Hello, It seems to be an issue in the top-level when loading the following program (say, p.pl):
:- initialization(main).
main :- repeat, read(X), X==stop.
By submitting 'ensure_loaded(p)' the program does not stop when reading the term 'stop'. However, the very same program without the initialization directive does return to the top-level when explicitly called with the goal 'main'. Is this a bug or a feature?
Dear Fernando,
there is an implicit failure after the execution of goals in 'initialization' directives. I have looked into the documentation but I found no mention to this behavior, which I would call a bug.
Temporary work-arounds are:
a) :- initialization((main, !)).
b) make sure that the goal in the initialization directive is semi-det (1 solution at most).
c) write your failure loops as:
main :- ( repeat, Loop, ExitCond, ! ; true ).
Cheers
a) :- initialization((main, !)).
Solved with this workaround. Thanks!
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Fernando Sáenz Pérez -
Jose F. Morales