Calling assertz/1 with stream-based clause

[thierrymarianne]

Hello,

I've tried to call assertz/1 by passing it a clause depending on a stream as follows:

test :-
	open('./learn/test-page.dj', read, Stream),
	assertz(stream('test', Stream)).

:- initialization(test).

Is there something i could do to make it work?

I wonder if some additional case(s) could be added to heap.rs.

The broader context is that I'm trying to make the prolog-based interactive prover LPTP to work with Scryer Prolog but I could not go past those lines. I started from GNU Prolog configuration file where assert/1 is declared with assertz/1 in its body.

[hurufu]

Panic should be fixed indeed, but you don't need to allocate stream handle on a heap manually. All streams can be inspected using stream_property/2. So in your case just leave the following in your program:

:- initialization(test).
test :-
	open('./learn/test-page.dj', read, Stream).

And then when you want to retrieve stream handle just do:

stream_property(Stream, file_name('./learn/test-page.dj')).

[hurufu]

Even better is to use stream alias:

:- initialization(setup_stream).
setup_stream :-
    open('file.pl', read, _, [alias(my_file)]).

And then you can use that alias freely throughout your program for example using read_term(my_file, T, []).

[thierrymarianne]

Thank you. That helps!

Yesterday, I also tried to unwrap the stream alias Option<Atom> before converting it as a Literal::Atom on the side to circumvent temporarily the encountered issue even though I can only assume proceeding as such makes for very little sense at heap.rs:76. However, I'd be happy to submit a proper fix with a little guidance.

HeapCellValueTag::Cons case was separated from loader.rs:1399 only so that I could make sure where the panic came from.