Re: Ann: SWI-Prolog 6.5.3

Paulo Moura <[email protected]>
Newsgroups gmane.comp.ai.prolog.swi
Message-ID <[email protected]>
Hi Richard,

On 21/11/2013, at 03:05, Richard A. O'Keefe <[email protected]> wrote:

> What I _want_ is to be able to declare in a source file what
> syntax settings that file is to be processed with *without* any
> effect on run time.  Is that possible?

One possible way to do it would be to change the semantics of the set_prolog_flag/2 *directive* to be local to a source file. The programmer could use the set_prolog_flag/2 *predicate* (called from an initialization/1 directive) if the effects of change should affect the runtime (*). But these would likely break backwards compatibility and the necessity of it is mitigated by using the set_prolog_flag/2 directive within a module (thus making it local to the module, not to the file; but given that a source file can only contain a single module definition...).

(*) Logtalk uses this distinction/semantics for its set_logtalk_flag/2 directive.

Cheers,

Paulo

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Paulo Moura
Logtalk developer

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Web:   <http://logtalk.org/>
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