Checking if a predicate exists within a specific module

[guregu]

Trealla's predicate lookup will scan all loaded modules as fallback, but is it possible to do a stricter check?

% foo.pl
:- module(foo, []).

is_foo.

% bar.pl
:- module(bar, []).

not_foo.

$ tpl foo bar
?- foo:current_predicate(not_foo/0).
   true. % is there some check that makes this false?

I played around with hacking search_predicate to only do the global search when q->st.m == q->pl->user_m for current_predicate/1 and it seems to work, but I have a feeling it might break something :-)

My use case is that I have a bunch of modules that may or may not define the same unexported predicates (something like entity definitions for a CRUD app), and I'd like to check if a particular module defines one, basically a crappy version of Logtalk protocols.

[infradig]

I'll have a look, obviously too lax.

…

On Mon, 13 Nov 2023, 20:09 guregu, ***@***.***> wrote: Trealla's predicate lookup will scan all loaded modules as fallback, but is it possible to do a stricter check? % foo.pl :- module(foo, []). is_foo. % bar.pl :- module(bar, []). not_foo. $ tpl foo bar?- foo:current_predicate(not_foo/0). true. % is there some check that makes this false? I played around with hacking search_predicate to only do the global search when q->st.m == q->pl->user_m for current_predicate/1 and it seems to work, but I have a feeling it might break something :-) My use case is that I have a bunch of modules that may or may not define the same unexported predicates (something like entity definitions for a CRUD app), and I'd like to check if a particular module defines one, basically a crappy version of Logtalk protocols. — Reply to this email directly, view it on GitHub <#389>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AFNKSEUK42LG2NAHQKWDEXLYEHWUFAVCNFSM6AAAAAA7I4PSD2VHI2DSMVQWIX3LMV43ASLTON2WKOZRHE4TAMZRHA2TQOA> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[infradig]

There's still work to do but as it currently stands...

~/trealla (devel) $ cat foo.pl
:- module(foo, [is_foo/0]).
is_foo.
private_foo.
~/trealla (devel) $ tpl foo
Trealla Prolog (c) Infradig 2020-2023, v2.30.2-dirty
?- current_predicate(is_foo/0).
false. % WRONG
?- current_predicate(foo:is_foo/0).
true.
?- foo:current_predicate(is_foo/0).
true.
?- bar:current_predicate(is_foo/0).
false. % WRONG, should be exception?
?- current_predicate(bar:is_foo/0).
false.
?-

[guregu]

Awesome, thank you. I'll play around with it tonight.

[guregu]

Tried it out a bit and it looks good, thanks!

[pmoura]

My use case is that I have a bunch of modules that may or may not define the same unexported predicates (something like entity definitions for a CRUD app), and I'd like to check if a particular module defines one, basically a crappy version of Logtalk protocols.

I'm curious. Prolog modules are an evolutionary dead-end. Why try hacks around modules and spend time on crappy versions of Logtalk features when Logtalk fully supports Trealla Prolog?

[guregu]

My use case is that I have a bunch of modules that may or may not define the same unexported predicates (something like entity definitions for a CRUD app), and I'd like to check if a particular module defines one, basically a crappy version of Logtalk protocols.

I'm curious. Prolog modules are an evolutionary dead-end. Why try hacks around modules and spend time on crappy versions of Logtalk features when Logtalk fully supports Trealla Prolog?

No good reason, really. Part of it is trying to understand (and improve) quirks in Trealla. Part of it is because I don't have a good way of distributing Logtalk-based programs for browsers yet (this is no fault of Logtalk). I made an issue in trealla-js, let me know if you have any ideas: guregu/trealla-js#26

[infradig]

I'm closing this.

[guregu]

Thanks @infradig!