Re: Ann: SWI-Prolog 6.5.1

Dear Samer,

If you want to stay compatible with SWI,
your current best bet is to use Yap Prolog.
Yap is to a large extent compatible with SWI. 
Your milage will depend on which SWI libraries you rely on.
I think the rule of thumb is that everything works except for 
libs that depend on threads and stuff that were added the last 6-12 months.

In development branch of Yap, Prism seems to be a standard library (please note that i have no experience with using this).
άμπελος;prism/exs% yap
YAP 6.3.4 (x86_64-linux): Wed Aug  7 15:07:41 BST 2013
MYDDAS version MYDDAS-0.9.1
 % reconsulting /home/nicos/.yaprc...
?-[library(prism)].
,,,,,,
,,,,,,
	including some worrisome warnings

?- prism(bloodABO),go,print_blood.
.....


You are right this scenario would be an excellent motivation for tabling.
As far as Prism is concerned, the SWI port would be mostly for educational reasons. 
I don't think that performance wise it can get anywhere near BProlog and Yap without serious
time investment.

SWI and Yap did great work a couple of years back and have to some extend continue 
this work to provide the same libraries. I think they actually use a common repository for some of them.
In an ideal word you either want
	a. Yap engine and Swi libs
	b. a common core API that will separate the libs from the inference engine,
	   thus making all libs automatically visible to both systems

Of course, this is from a user perspective.
Developers obviously have different priorities, such as viability, finance, prestige and guarding of user-bases among others.

Regards,


Nicos Angelopoulos
---
http://bioinformatics.nki.nl/~n.angelopoulos


On Tue, 13 Aug 2013 09:13:11 +0000
"Abdallah, Samer" <[email protected]> wrote:

> Hi Jan,
> Thanks for the new version - I have a few versions to catch up now,
> but if you're wondering what to do next, might I suggest …
>  [whispering] tabling?
> I'd love to be able to implement something like this
> 	http://sato-www.cs.titech.ac.jp/prism/
> on SWI. BProlog seems like a good Prolog but in terms of general
> usability, not to mention my investment in libraries, SWI is a lot better
> for me. I realise adding any sort of efficient tabling probably involves a major 
> reworking of the base code - is it at all doable?
> 
> Samer.
> 
> On 12 Aug 2013, at 21:43, Jan Wielemaker <[email protected]>
>  wrote:
> 
> > Hi,
> > 
> > I've uploaded SWI-Prolog 6.5.1.  There are a lot of changes.  Highlights:
> > 
> >  - Detection of `semantic singletons' by the compiler.  This proofs
> >    to result in a quite high percentage of real bugs.  My rough
> >    estimate is about 1/3th!  And this is on established code!
> >  - Singleton detection with quasi quotations (do not claim a
> >    singleton of a QQ introduces a reference to the singleton
> >    in its expansion).
> >  - prolog_load_context/2 provides access to variable names.
> >  - term_expansion/4 and goal_expansion/4 to allow converting
> >    source layout information.  This goes through most of the
> >    compiler toplevel, but isn't actually used yet.
> >  - halt/0 can now be called from threads.  Various fixes to
> >    program termination, notably for xpce on Windows.
> >  - JPL dll hassle is hopefully resolved.
> >  - Cygwin port is updated.
> >  - Lots of small stuff and cleanup.
> > 
> > Not sure where to go with the stable version.  I first thought just
> > cherry-picking the clear fixes, but there are so many that I consider
> > updating to the devel version after the devel version proofs to be
> > stable.  Please report issues with the above changes.
> > 
> > 	Enjoy --- Jan
> > 
> > 
> > ========================================
> > SWI-Prolog Changelog since version 6.5.0
> > ========================================
> > 
> > * DOC: keysort/2
> > 
> > * ENHANCED: CLP(FD): isolate global_cardinality/2 from user attributes.
> >   Before:
> > 
> >      %?- put_attr(A, edges, [a]), global_cardinality([A,B,C], [0-_,1-_]).
> >      %@ false.
> > 
> >   Now:
> > 
> >      %?- put_attr(A, edges, [a]), global_cardinality([A,B,C], [0-_,1-_]).
> >      %@ put_attr(A, edges, [a]),
> >      %@ A in 0..1,
> >      %@ global_cardinality([A, B, C], [0-_G4383, 1-_G4389]),
> >      %@ B in 0..1,
> >      %@ _G4383 in 0..3,
> >      %@ C in 0..1,
> >      %@ _G4389 in 0..3.
> > 
> > * FIXED: Dummy empty warning if no compiler warning refers to a variable.
> > 
> > * ENHANCED: CLP(FD): Better isolation from user-defined variable
> >   attributes.  Example:
> > 
> >      :- use_module(library(clpfd)).
> > 
> >      distinct(Vars) :- Vars = [A,B,C,D], all_distinct(Vars), [A,B,C]
> >              ins 0..2.
> > 
> >   Before:
> > 
> >      %?- put_attr(X, edges, [x]), Vars = [X|_], distinct(Vars).
> >      %@ false.
> > 
> >   Now:
> > 
> >      %?- put_attr(X, edges, [x]), Vars = [X|_], distinct(Vars).
> >      %@ Vars = [X, _G1856, _G1859, _G1862],
> >      %@ put_attr(X, edges, [x]),
> >      %@ X in 0..2,
> >      %@ all_distinct([X, _G1856, _G1859, _G1862]),
> >      %@ _G1856 in 0..2,
> >      %@ _G1859 in 0..2.
> > 
> >   That is, users can freely use the "edges" attribute themselves.
> > 
> > * ENHANCED: CLP(FD): Remove branch singletons.
> > 
> > * FIXED: Inlined unification must revert to normal unification if occurs
> >              check is active.
> > 
> > * TEST: compensate for optimization
> > 
> > * FIXED: Mixup in truth of == and \== predictable warnings.  Keri Harris.
> > 
> > * ADDED: Move multiton detection into the compiler, so this compiles
> >     clean: == t :- (v(_A);v(_A)).  ==
> > 
> > * FIXED: Detection of `multitons' (broken after singleton detection
> >     extension for dealing with quasi quotations).
> > 
> > * FIXED: myplus/4 in bounds.pl.  Note that bounds is deprecated in
> >     favour or library(clpfd).  Markus Triska.
> > 
> > * ENHANCED: :- at_halt/1 is now term-expanded, such that reloading the
> >     file does not re-register the hook.
> > 
> > * FIXED: Apply changes that where missed due to a git conflict
> > 
> > * UPDATED: Handle new PL_on_halt() interface
> > 
> > * MODIFIED: Program termination: - at_halt/1 handlers can veto
> >       termination of halt/0 by calling
> >         cancel_halt/1.  - PL_at_halt() handlers now have a declared
> >       return type.  In
> >         the future, they will be able to cancel termination by
> >         returning a non-zero status.  Now a warning is printed.  -
> >       halt/1 and PL_halt() can be called from any thread.
> > 
> > * FIXED: set_stream/2 issues with recent patch
> > 
> > * ENHANCED: safe_goal/1, various enhancements: - Distinguish undefined
> >     predicates - Deal with library meta-predicates (security fix) -
> >     Module aware call/N support - Print context of encountered problem
> > 
> > * CLEANUP: Use DCG // notation for declarations
> > 
> > * FIXED: license/1: list known licenses (found by singleton analysis)
> > 
> > * ENHANCED: read_term/3: singleton detection with quasi
> >     quotations. Variables appearing only ones are searched in the quasi
> >     quotation results.  If found there, they are no real singletons.
> > 
> > * ADDED: library(sandbox): added a lot of safe primitives.
> > 
> > * FIXED: safe_goal/1: Catch instantiation_error when trying to proof
> >     safety of a general goal.
> > 
> > * MODIFIED: Make set_stream/2 behave sensibly on stream pairs. Daniël
> >     de Kok.
> > 
> > * CLEANUP: Implementation of set_stream/2.
> > 
> > * ADDED: Singleton checking inside \+
> > 
> > * DOC: var_branches style check
> > 
> > * CLEANUP: Removed two useless assignments
> > 
> > * FIXED: nb rbtrees (singleton)
> > 
> > * MODIFIED: Setting style_check/1 and expects_dialect/1 in ~/.plrc
> >     changes the default for the session.  The settings used to be
> >     scoped to the file.  This scoping is now controlled by a new option
> >     =scope_settings= to load_files/2.
> > 
> > * ADDED: style_check/1: ?- style_check(?(Style)). to return active
> >     style checks on backtracking.
> > 
> > * DOC: term_expansion/4, etc.
> > 
> > * DOC: Document extended singleton warnings
> > 
> > * DOC: style_check/1 new =no_effect= option
> > 
> > * DOC: user term_expansion is followed by DCG!
> > 
> > * CLEANUP: Avoid new warnings in test cases.  Test cases sometimes use
> >     ugly code by design ...
> > 
> > * ADDED: compiler warnings for BIPS that have no effect and singleton
> >     variables in branches (semantic singletons).
> > 
> > * ADDED: Support for warning messages from the compiler
> > 
> > * ADDED: Provide prolog_load_context/2 =variable_names= and implemented
> >     goal/term expansion with 4 arguments to process layout information.
> > 
> > * FIXED: Default handling in setting (spotted by variable balance
> >     checking)
> > 
> > * CLEANUP: some documentation glitches
> > 
> > * ADDED: New style-check options.  We will include these into the stable
> >     branch to avoid warnings on code calling style_check/1.
> > 
> > * TEST: Fixed test code for timeout handling.
> > 
> > * CLEANUP: Removed bogus test
> > 
> > * FIXED: Remove meta_predicate/1 declaration for '|'/2.  This is since
> >     long not a predicate anymore.
> > 
> > * CLEANUP: Use '$type_error'/2.
> > 
> > * FIXED: Colourise [:|+] meta-declaration.
> > 
> > * CLEANUP: Rename $-predicates in DCG expander. This is not needed since
> >     this code is in a module. Also removed a lot of outdated comments
> >     and added some new ones.
> > 
> > * FIXED: base32//1: Singleton I3
> > 
> > * CLEANUP: library(clpp/bounds): singletons.  Not sure whether this
> >     was intended.
> > 
> > * CLEANUP: Branch singletons
> > 
> > * CLEANUP: Unification against unused variable
> > 
> > * CLEANUP: In DCG, \+ \+ {...} leads to useless unifications.  We now
> >     use { \+ \+ G }.  That remains silent.  Eventually, this can (and
> >     should) be improved in the DCG compiler.
> > 
> > * FIXED: Emulated shell commands for non-atom arguments.
> > 
> > * FIXED: library(prolog_pack): parsing of versions with * in them.
> > 
> > * FIXED: Pass thread-reference in all branches
> > 
> > * FIXED: library(prolog_colour) to colour "..." terminals properly
> > 
> > * PORT: Cygwin: install package shared objects in the right
> >     location. Corinna Vinschen.
> > 
> > * PORT: Updated Cygwin port by Corinna Vinschen
> > 
> > * FIXED: make/0: avoid loading files twice.  Paulo Moura.
> > 
> > * FIXED: PL_thread_engine_attach() did not initialise the thread
> >     locale. Carlo Capelli.
> > 
> > * FIXED: Make sure the config var SO_PATH is set to PATH in Windows,
> >     and not WINEPATH.
> > 
> > * CLEANUP: Avoid using SO_PATH for two different purposes
> > 
> > * FIXED: DCG argument of phrase_from_stream/2 is not identified as such
> >     (meta_predicate/1).
> > 
> > 
> > 
> > =========
> > Package R
> > =========
> > 
> > * FIXED: Mixup of Ruo/Ro variables in r_lines/6
> > 
> > ===============
> > Package archive
> > ===============
> > 
> > * PORT: Deal Win64 off_t handling
> > 
> > ===========
> > Package chr
> > ===========
> > 
> > * ADDED: style_check(-no_effect) to compensate for some unifications
> >   that have no effect.  Suggests that is some room for optimization.
> > 
> > * CLEANUP: Avoid (extended) singleton warnings.
> > 
> > * FIXED: delete_first_ht/3: Not only compute load, but also update it.
> > 
> > ============
> > Package clib
> > ============
> > 
> > * UPDATED: Handle new PL_on_halt() interface
> > 
> > * PORT: Cygwin updates by Corinna Vinschen
> > 
> > ===========
> > Package cpp
> > ===========
> > 
> > * DOC: Document PREDICATE0() and NAMED_PREDICATE()
> > 
> > * ADDED: PREDICATE0(name) as alternative to PREDICATE(name, 0) that
> >   avoids unused parameter warnings.
> > 
> > * MODIFIED: NAMED_PREDICATE() takes a string as name.
> > 
> > * FIXED: PREDICATE() macro issues
> > 
> > * ADDED: Macros NAMED_PREDICATE() and NAMED_PREDICATE_NONDET() to
> >   allow defining predicates that have a name that cannot be expressed
> >   as a C identifier.  This patch also casts unused variables to (void)
> >   to avoid warnings.  With help from Carlo Capelli.
> > 
> > ============
> > Package http
> > ============
> > 
> > * CLEANUP: More elegant implementation for computing byte-length
> >   in encoding
> > 
> > * CLEANUP: Branch singletons
> > 
> > * CLEANUP: Another branch singleton.
> > 
> > * FIXED: Singleton in interactive_httpd->authorise causes poor error
> >   message.
> > 
> > * CLEANUP: Removed detection of unused OpenID NS
> > 
> > * INSTALL: Avoid double installation of shared objects. Corinna Vinschen.
> > 
> > * DOC: Improved documentation of cookie handling
> > 
> > 
> > ===========
> > Package jpl
> > ===========
> > 
> > * PORT: Use win_add_dll_directory/1 and generalise the search a bit
> > 
> > =============
> > Package pldoc
> > =============
> > 
> > * CLEANUP: Avoid semantic singleton message
> > 
> > ==============
> > Package plunit
> > ==============
> > 
> > * FIXED: Only share variables between options and body to maintain
> >   first-var and singleton properties.
> > 
> > * CLEANUP: Singletons
> > 
> > ==============
> > Package semweb
> > ==============
> > 
> > * FIXED: Avoid unlocking the RDF store directory twice.
> > 
> > * FIXED: rdfe_undo (bug found by balanced var check)
> > 
> > * FIXED: Loading Turtle from a stream did not reset the stream encoding.
> > 
> > * FIXED: Detecting subjects for turtle writer.
> > 
> > =============
> > Package space
> > =============
> > 
> > * FIXED: sem_time_candidate
> > 
> > * FIXED: owl_time_xsd_candidate/3 error spotted by singleton detection.
> > 
> > ===============
> > Package windows
> > ===============
> > 
> > * CLEANUP: Do not ignore return values and delete dead code.
> > 
> > ============
> > Package xpce
> > ============
> > 
> > * FIXED: Locking issue that causes long delays on halt if xpce is
> >   running in separate thread.
> > 
> > * FIXED: Two new singleton warnings (one was a bug).
> > 
> > * FIXED: Priority issue in GUI term pretty printer
> > 
> > * UPDATED: Handle new PL_on_halt() interface
> > 
> > * ENHANCED: Allow cancelling halt
> > 
> > * CLEANUP: Variable style issues.
> > 
> > * PORT: Rename installation helper xpce-install into xpce-copy to prevent
> >   Windows from trying to run this program as admin.  Corinna Vinshen.
> > 
> > * FIXED: Start xpce from a background thread.
> > 
> > * PORT: update of the Cygwin port by Corinna Vinschen
> > 
> > * CLEANUP: Avoid more semantic singletons
> > 
> > * FIXED: Semantic singletons.  One fixes a bug in the class
> >   prolog_predicate.
> > _______________________________________________
> > SWI-Prolog mailing list
> > [email protected]
> > https://lists.iai.uni-bonn.de/mailman/listinfo.cgi/swi-prolog
> 
> 
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