Ann: SWI-Prolog 9.3.22

Releases
1

Dear SWI-Prolog user,

I’m happy to announce SWI-Prolog 9.3.22. The Changelog is long.
Highlights:

  • Support configurations that install the .qlf (Quick Load Files)
    next to the sources for all libraries. This is enabled using
    cmake -DINSTALL_QLF=ON. This is not yet default in this
    release. If you build from source, please try this. It reduces
    library load times a lot. If, for some reason, you want to try
    using the source for some run, use swipl -Dsource ...

  • Support installing the libraries as only .qlf files. This
    is enabled using cmake -DINSTALL_PROLOG_SRC=OFF. It seriously
    reduces the size of the installation, but debugging and inspecting
    the Prolog source for some predicate is of course a lot harder.
    Currently used by SWI-Tinker. SWI-Tinker allows viewing the
    library sources as they are downloaded on demand. This will not
    become default, possibly except for the npm package?

  • A lot of cleanup and fixes to support the two above features.
    One of them is a change to the library INDEX.pl files to provide
    information on meta-predicates, public predicates and operators
    provided by the library modules. Old INDEX.pl file are still
    read to minimise impact for people using this on private libraries.

  • Many changes for the WASM version. Added various options to the
    JavaScript API. Moved bind/4 from library(dom) to library(wasm)
    and added bind_async/4 and wait/3 as wait(+Element, +EventType, -Event). Extended
    library(dom) to fully implement the same library as found in
    Tau-Prolog.

  • Various fixes to the debugger, mostly fixing regression due to
    the introduction of yield based debugging.

  • Modified edit/1 internals. This affects code using the
    edit:edit_source/1 hook to call a user-defined editor.

  • Fixed various issues with term//2, rendering Prolog terms as nested
    <span> elements.

    Enjoy — Jan

SWI-Prolog Changelog since version 9.3.21

  • FIXED: Using tabling when configured for debugging with autoloading
    disabled.

  • WASM: Enhanced error message when evaluating :=/2

  • FIXED: Clear FR_SKIPPED after skip/up in yield-based debugger.

  • FIXED: continue in trace mode after hitting a spy point. This was
    broken when using Prolog defined tracing in recent rewrites.

  • FIXED: Retrieving source info for Head --> "terminal", ...

  • DEBUG: Attempt to improve visible trace points in the debugger.

  • FIXED: xref_public_list/3 on absolute .pl file on qlf-only release.

  • FIXED: file_autoload_directives/3: Handle absence of sources Use
    public xref_public_list/3 rather than a private predicate from
    boot/autoload.pl that is designed for source only.

  • FIXED: library(dom) get_by_id/2: getElementById() returns null
    on failure

  • WASM: library(dom): Tau-Prolog compatible handling of set_style/3 and
    get_style/3 Several DOM style strings are translated to Prolog terms.

  • ADDED: library(dom): remove_class/2.

  • WASM: Move bind/4 from library(dom) to library(wasm) Also added wait/3.

  • DOC: Added library(wasm) and library(dom) to documentation server.

  • DOC: library(wasm)

  • ADDED: WASM: Prolog.promise_event()

  • WASM: bind/4 can now handling JavaScript objects without using the
    database

  • WASM: Updated bind.html demo.

  • ADDED: Complete the Tau-Prolog compatibility library(dom).

  • ADDED: WASM: Allow for nested #(Value)

  • WASM: Prolog.bind(): added options.

  • BUILD: Install pldoc/hooks.pl instead of the .qlf file This is an
    include file that is used by the web server to customise PlDoc.

  • FIXED: library(prolog_colour): handle non-ground directives. E.g. :- use_module(mymodule, [op(_,_,_)]).

  • MODIFIED: prolog:xref_update_syntax/2 This hook is now called both with
    the raw and expanded terms. Directives are called as (:- Directive)
    rather than the plain term.

    The hook was (no longer) used, so this should have limited impact.
    It is now introduced for library(http/html_write).

  • FIXED: library(prolog_xref): missing multifile declaration.

  • FIXED: library(prolog_colour): style mismatch for multifile heads.

  • ADDED: Support access to public predicates for library indexes

  • ADDED: xref_public_list/2: get information from library INDEX.pl
    Using the INDEX.pl file provides a fast and simple way to get the
    library exports and meta-predicate information. Still need to deal
    with public predicates.

  • MODIFIED: INDEX.pl files. Thes files used to contain

    • index(Name, Arity, Module, File)

    This is now modified to

    • index(Head, Module, File)

    Where Head contains (where known) the mode and/or meta-predicate
    indicators. The index files now also contain the op(Pri,Type,Name)
    terms from the export list.

    This provides faster and simpler access to meta-predicate and
    operator relations between modules.

  • FIXED: edit/1 using edit(file(File)).

  • FIXED: edit/1: find e.g. library(lists) if only qlf files are
    installed.

  • DOC: #1358 prolog_stack_frame_property/2

  • ADDED: prolog_colourise_term/4: option current_variable(Name)
    This causes the marking to mark the named variable with the class
    current_variable.

  • WASM: Prolog.consult(): added engine:true option. This allows
    loading files to proceed asynchronously.

  • ADDED: xref_source/2: stream(In) option This allows processing
    arbitrary data.

  • WASM: Do not install the package build tools.

  • ADDED: qlf app swipl qlf info -e file.qlf Show exports of the
    .qlf file.

  • ENHANCED: library(prolog_xref) without sources Get exports from
    .qlf files.

  • MODIFIED: edit/1: use dicts for representing (partial) locations.
    As a result, hooks info the editing infrastructure need to be updated.

  • ENHANCED: edit/1 - Feedback on locations - Code simplification and
    modernizing

  • CLEANUP: edit/1 - Avoid deprecated us of absolute_file_name/3. -
    Avoid proposing .qlf files.

  • ADDED: prolog_file_directives/3 This predicate used to be part of
    library(prolog_xref). It is now public from library(prolog_source).

  • DOC: Update CMAKE.md to include instructions on Python installation
    Added a list of the options useful for installing Janus

  • DOC: install with symlinks

  • WASM: Use lz4 compression for data file.

  • WASM: Demo server to serve library sources.

  • WASM: Support library(chr). The package was compiled, but only
    partially installed and thus non-functional.

  • WASM: Enable adding packages in the node version This was disabled
    due to issues with Emscripten opendir(), but these seem resolved.

  • WASM: Support INSTALL_QLF and INSTALL_PROLOG_SRC CMake flags

  • WASM: Remove several libraries that cannot be supported

  • BUILD: Allow qlf builds without PlDoc and xpce

  • DOC: WASM function Prolog.query() Documented nodebug and string
    options.

  • WASM: Prolog.query(): add option {string:"atom"}

  • ENHANCED: Generalise user interaction on answer Allow reusing the
    toplevel answer user interaction by using an alternative input.

  • ENHANCED: qlf app to report .qlf files without sources. Used to
    report these as out of data.

  • FIXED: We must insert I_CONTEXT in multifile predicates Multifile
    predicates are typically installed in modules using target:head :- body, where body is executed in the containing module. This is
    achieved using an I_CONTEXT VM instruction. Before, when the predicate
    contains one such clause, it set P_MFCONTEXT and inserted a
    I_CONTEXT for each subsequent clause. When using .qlf files though,
    the files may be loaded in different order than when creating the
    .qlf files, leading to clauses without an I_CONTEXT instruction to
    follow clauses with this.

  • ENHANCED: library(prolog_xref): cleaner exception handling.

  • ENHANCED: Allow cross-referencer to deal with .qlf files

  • BUILD: Added CMake option -DINSTALL_PROLOG_SRC=OFF This can be
    used together with -DINSTALL_QLF to ship the Prolog libraries as
    .qlf files without including the sources.

  • FIXED: Handle autoload/1,2 declarations in aggregate .qlf files

  • FIXED: load_files/2: resolve to files loaded from .qlf Some qlf
    files may load multiple source files. When looking for a file in
    e.g. use_module/1,2, first try the file system, but on failure ee
    whether we loaded a .qlf file that registered the required file.

  • FIXED: Use canonical .pl files for all admin purposes. Despite the
    fact that code is loaded from .qlf files, use the .pl file from which
    the .qlf file is compiled for admin purposes.

  • ADDED: ‘$qlf_module’(+File, -Dict) This predicate extracts properties
    for a module without loading it. This is required to make autoload/1,2
    work if we remove the source files.

  • MODIFIED: absolute_file_name/3: distinguish file types prolog and
    source These used to be synonyms. Now prolog includes .qlf
    and source does not.

  • INSTALL: Install .qlf files if these have been build.

  • ADDED: library(prolog_qlfmake) This library allows for compiling the
    entire library to .QLF files.

  • ADDED: Prolog flag source. This flag can be used to ignore the
    .qlf files in the library and load the .pl (source) files instead.

  • ADDED: library(prolog_qlfmake) This library allows for compiling the
    entire library to .QLF files.

  • FIXED: Do not keep an erased clause when doing an incremental
    compilation

  • ENHANCED: qcompile/1: preserve predicate properties When compiling
    clauses for another module as commonly done as a return of
    term_expansion/2, preserve the multifile and dynamic properties,
    such that the module can be loaded as qlf and later loading of the
    module into which the clauses are added does not wipe the predicate.

  • FIXED: Debugging the fail port of Prolog defined built-in predicates.

  • FIXED: If engines are enabled without threads, call the main engine
    main.

Package http

  • FIXED: term//1: possible exception on compound_name_arity/3.
    This happened when spacing around operators need to be computed and
    the left or right hand of the operator is a blob.

  • FIXED: Running out of file descriptors if device for log files
    is full. This patch is a serious cleanup of error handling in the
    HTTP log library.

  • ADDED: Provide cross-referencing hooks for :- html_meta(+Decls)

  • FIXED: #168 http_daemon/0,1: exit with status 0 The startup was
    translating all exceptions into halt(1). That is wrong after halt
    is implemented as throw(unwind(halt)).

  • FIXED: library(http/jquery): support Qlf compilation ensure_jquery/1
    cannot use conditional compilation. We must use a runtime conditional
    instead.

  • CLEANUP: Avoid demo dependency on xpce.

  • FIXED: term//2: make operators a trigger.

  • FIXED: term//2: portray(true) implies numbervars(true).

Package pldoc

  • ADDED: PlDoc to LaTeX converter: file_synopsis(Text) option Allows for
    overwriting the default synopsis. Used to document some not-installed
    libraries.

  • ADDED: Support “=” mode. This is a proposal in the PIP meetings to
    deal with “Output” arguments.

Package xpce

  • ENHANCED: PceEmacs: reload styles if new style facts are added.
    This is necessary if Prolog files that hold highlight declarations
    are loaded after creating the editor.

  • BUILD: Build xpce library index before running qlf_make/0

  • ENHANCED: PceEmacs: deal with possibly not-installed sources.

  • FIXED: Add dependencies to make qlf compile work qlf_make/0 now
    reorders based on file dependencies. This means we can add the
    dependencies here and avoid hacks.

  • FIXED: Load library(emacs_extend) explicitly in mode files This is
    required to ensure that the term expansion is applied when generating
    the .qlf files.

  • CLEANUP: Remove pce_boot search path. Now using hard paths to resolve
    references between the various boot files.

  • BUILD: Better support building .qlf files without an X11 display

  • CLEANUP: Removed forgotten HTTP implementation

  • CLEANUP: Delete duplicate libraries Deleted

    • pce_drag_and_drop.pl (duplicate of dragdrop.pl)
    • pce_drag_and_drop_dict_item.pl (duplicate of dragdict.pl)
    • pce_loadcxx.pl (non-functional)
    • pce_selection.pl (old, deprecated)
    • sp_fcompile.pl (non-functional)
3 Likes
2

See post here, library(dom) is slightly incomplete.

The Tau-Prolog streamable DOMs were not ported it seems.

What is the rational to exclude it?

3

There is a further difference from SWI-Tinker to Tau-Prolog.
Tau-Prolog has no (#)/1. So in SWI-Tinker I need to write:

/* SWI-Tinker */
setup :-
    body(Body),
    create('div', Elem),
    set_attr(Elem, #id, #writeme),
    append_child(Body, Elem).

But in Tau-Prolog I can do without (#)/1:

/* Tau-Prolog */
setup :-
    body(Body),
    create('div', Elem),
    set_attr(Elem, id, writeme),
    append_child(Body, Elem).

If I try the Tau-Prolog version in SWI-Tinker I get this error:

image

4

Thanks. That is a bug. Fixed (and updated SWI-Tinker). There has been little testing on these predicates. I didn’t find a test suite. I ported one of the Tau examples, which you can see at Tau Prolog - Example: My little doge. The porting work was limited to changing how Prolog is loaded and get it running. That spotted a couple of discrepancies between what I implemented based on the documentation and what actually happened. There may be more issues :frowning:

1 Like
5

Yeah I could see the little dog. Cool!

But something changed, and I now get this error in SWI-Tinker.
I didn’t issue use_module(library(dom)), nor did I have open
a Prolog text that had some of the predicates body/1 etc..:

ERROR: /swipl/library/dom.pl:47:
ERROR:    Unhandled exception: No permission to run goal `load_file(wasm)'
Warning: /swipl/library/dom.pl:47:
Warning:    Goal (directive) failed: dom:use_module(wasm)

https://wasm.swi-prolog.org/wasm/tinker

Edit 04.04.2025
Also the ESC 8 for links doesn’t work on Windows 11, the link is
not shown. SWI-Tinker shows the link, some ASCII consoles
might also show it, but this one doesn’t understand the control:

image
image716×327 73.2 KB

Maybe a further SWI startup parameter would do?

6

Thanks. Fixed. I pushed a number of changes that move the Tau-compatible library(dom) to use the “dialect” mechanism, so if you want to use the Tau DOM access, you now need

:- expects_dialect(tau).
:- use_module(library(dom)).

or

:- use_module(library(dialect/tau/dom)).

The first offers more options for emulating Tau-Prolog (but nothing is implemented). The latter just loads Tau’s dom library.

Just library(dom) now gets SWI-Prolog’s DOM library. What that does is still a bit open. For now it provides a html//1 that does not generate HTML text, but it produces a list of JavaScript HTMLElement objects. It allows for Var=Spec at any point to bind Var to the element created by Spec. The library also provides append_html(+Elem, +Spec) to extend the content of any element that understands appendChild(). Finally, the new library contains the browser event binding predicates. We’ll see how it develops.

The URL embedding was used for all terminals for absolute URLs. Made dependent on the hyperlink_term flag. That flag is false by default. Tinker implements these hyperlinks and explicitly enables this flag. If you want to use it, you must explicitly enable it in your init.pl. It works on most modern Linux terminal emulators, so you can open links to external resources and files using Ctrl-click,

8

See also hyperlnk _term flag and SWI-Prolog banner? [Windows 11] · Issue #1361 · SWI-Prolog/swipl-devel · GitHub

Ideally, clear bugs go into github issues and anything else here. But, of course it is not always clear to users what a real bug is. This surely classifies.