Ciao-users November 2001

ciao-users@cliplab.org

6 participants
8 discussions

ODBC Mediator? (repeat post due to foul up)...
by Guy Murphy 27 Nov '01

27 Nov '01

[ sorry for the repeat post, but system clock was out of whack and likley yo result in my post getting berried undre a pile of e-mail ] ---- Hiyas. Can anybody point me to the ODBC Mediator for Ciao... it's not included in either the most current distro or the "stable" distro... a degree of ODBC support was one of the reasons I chose Ciao, I'm liking it and would regret having to ditch it over ODBC. Oh, windows binaries along with source would be a dream, but I'll settle for source =) Cheers, Guy

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Re: Trouble with module which wants to import and export
by Daniel Cabeza Gras 26 Nov '01

26 Nov '01

Dear Greg, The solution depends on the exact scenario. If there is only one client module, and it has a fixed name, then doing the client an the search module mutually dependent with normal use_module declarations will suffice. I suppose the problem is that the client module name may change, and possibly that there can be multiple client modules. If there is only one client module, then declaring :- multifile successor/2. both in the client and the search module will do the trick. This is not correct if there can be multiple client modules, because the successor/2 clauses will got merged. The really nice thing in that case would be to use Ciao's higher-order capabilities, adding to path/3 a higher-order argument to hold the predicate to call. As an example, lets suppose the path/3 code would be as simple as: path(Start, Start, []). path(Start, End, [Next|RestPath]) :- successor(Start, Next), path(Next, End, RestPath). The new path/4 code would be: :- meta_predicate path(_,_,pred(2),_). path(Start, Start, _Succ, []). path(Start, End, Succ, [Next|RestPath]) :- Succ(Start, Next), % equivalent to call(Succ, Start, Next) path(Next, End, Succ, RestPath). and in the client, if locally is defined successor/2 (any name possible), the call to path/4 would be: ... path(E0, Ef, successor, Path) ... Note that in the coming Ciao version (but not in 1.6), to use higher order the hiord package is needed, so a declaration as :- use_package(hiord). would be needed in the path/4 module source. Regards, Daniel Cabeza

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Re: Trouble with module which wants to import and export
by Manuel Carro 26 Nov '01

26 Nov '01

>> I'm trying to port some Prolog code I wrote some time ago >> to Ciao and I'm having trouble figuring out the right way to >> use the Ciao module system. I have some path searching modules >> which have the following interface; >> >> % Requires: >> % successor( Given state, Successor state ). >> % Provides: >> % path( Given start state, Given goal state, Path from start to goal ). >> >> That is, they import successor/2 from the domain code >> (the client module) and provide path/3 back. >> >> I'm not figuring out how to write these mutually dependent modules. >> What am I missing? Can't you just write them as the samples below (and please correct me if I misunderstood anything): File a.pl: ___________________________________________________________________________ :- module(a, [whatever/0]). :- use_module(b). whatever:- whichever. ___________________________________________________________________________ File b.pl: ___________________________________________________________________________ :- module(b, [whichever/0]). :- use_module(a). whichever:- whatever. ___________________________________________________________________________ These above are accepted by Ciao Prolog, even if mutually dependent. -- || Manuel Carro -- DLSIIS || || e-mail: mcarro(a)fi.upm.es || || http://lml.ls.fi.upm.es/~boris || || http://clip.dia.fi.upm.es/Software/Ciao || || Phone: +34 91 336-7455 FAX: +34 91 336-7412 ||

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Trouble with module which wants to import and export
by J. Greg Davidson 24 Nov '01

24 Nov '01

I'm trying to port some Prolog code I wrote some time ago to Ciao and I'm having trouble figuring out the right way to use the Ciao module system. I have some path searching modules which have the following interface; % Requires: % successor( Given state, Successor state ). % Provides: % path( Given start state, Given goal state, Path from start to goal ). That is, they import successor/2 from the domain code (the client module) and provide path/3 back. I'm not figuring out how to write these mutually dependent modules. What am I missing? Thanks in advance, _Greg -- J. Greg Davidson jgd(a)well.com

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Re: Problems with concurrent facts and classes
by Francisco Bueno Carrillo 21 Nov '01

21 Nov '01

jsabater(a)iiia.csic.es says: >> The probem is the following. Although message/1 is declared as >> concurrent, when the predicate main/0 arrives to the second >> retract_fact(message(B)) instead of waiting, it fails (as if message/1 was >> declared as data or dynamic). What's wrong in my code? There's nothing wrong, in fact. Concurrent attributes are not working yet in Ciao (neither in 1.6 #3). We will try to put it working for 1.8 (coming soon). If what you want is not a concurrent attribute (different for each instance) but a concurrent fact (common for all instances), i.e., a concurrent *class* attribute, then you can define it in a separate module and import it into the class. This workaround is the way to define class attributes in OCiao, whether concurrent or not. This will do: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% :- class(test,[],[]). :- use_module(testattributes,[message/1]). :- export([main/0]). main :- asserta_fact(message(a)), retract_fact(message(A)), display(A),nl, retract_fact(message(B)), display(B),nl. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% :- module(testattributes,[message/1],[]). :- concurrent message/1. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Now, you can simulate a concurrent instance attribute by indexing the concurrent class attribute. Something like this: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% :- class(test,[],[]). :- use_module(testattributes,[message/2]). :- export([main/0]). main :- self(S), asserta_fact(message(S,a)), retract_fact(message(S,A)), display(A),nl, retract_fact(message(S,B)), display(B),nl. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% :- module(testattributes,[message/2],[]). :- concurrent message/2. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Ok. This makes the predicate concurrent for every instance of the class. What you can do to avoid this is to create concurrent predicates dynamically for each instance, using the library(concurrency):concurrent/1 predicate. This will require some more programming... ;-) Regards, Paco ------- End of forwarded message -------

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Re: Compiling static executables
by Daniel Cabeza Gras 21 Nov '01

21 Nov '01

Dear Miguel, Currently there is no support for the -S option in Windows. We are working on it. Daniel Cabeza

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Compiling static executables
by f980299＠zipi.fi.upm.es 21 Nov '01

21 Nov '01

Hello, I have a problem with the Ciao standalone compiler. I am trying to compile an static executable with ciaoc on Windows, and I get the following error message: ERROR: File //C/Archivos de programa/ciao-1.6p3Win32/engine/ciaoengine.Win32i86. sta not found - aborting... I haven't found this file in my installation, nor the directory engine. The command I use to copile is: c:\archiv~1\ciao-1~1.6p3\ciaoc\ciaoc -S -o alex.exe alex.pl I've tryed both under WindowsMe and Windows 2000. Thank you very much for your help. Miguel

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Re: Problems with modules.
by MCL 09 Nov '01

09 Nov '01

>> This is really a problem of a novice Ciao user. >> The toplevel/compiler within emacs environment >> gives me the following output: >> >> ?- append(A,B,[1,2,3]). >> {ERROR: user:append/3 - undefined predicate} The toplevel acts, in many ways, as another module. So you have to explicitly load the modules containing the predicates you intend to use. In this case, Ciao-Prolog 1.7 #132: Wed Oct 31 19:34:53 CET 2001 ?- use_module(library(lists)). Note: module already in executable yes ?- append(A, B, [1,2,3]). A = [], B = [1,2,3] ? ; A = [1], B = [2,3] ? ; A = [1,2], B = [3] ? ; A = [1,2,3], B = [] ? ; no ?- Note the first "use_module". Additionaly, if you load into the toplevel a module, say `f', which in turn uses another module, e.g., `lists', the module lists is not made automatically visible at the toplevel, even if it was already loaded. MCL ________________________________________________________ Virtuosity is no big deal, if you don't mind practicing.

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Ciao-users November 2001