%%% -*- Mode: Prolog; -*- %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % Author: Vitor Santos Costa % E-mail: vsc@dcc.fc.up.pt % Copyright (C): Universidade do Porto %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % This file is part of the YAP Python Interface % distributed according to Perl Artistic License % check LICENSE file for distribution license % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%% :- module(python, [ init_python/0, end_python/0, python_command/1, python_assign/3, python_import/1, python/2, (:=)/2, (:=)/1, (<-)/2, (<-)/1, op(100,fy,$), op(950,fy,:=), op(950,yfx,:=), op(950,fx,<-), op(950,yfx,<-), op(50, yf, []), op(50, yf, '()'), op(100, xfy, '.'), op(100, fy, '.') ]). /** <module> python A C-based Prolog interface to python. @author Vitor Santos Costa @version 0:0:5, 2012/10/8 @license Perl Artistic License This is an interface to allow calling Python from Prolog. Please look at the SWIG package if you want to embedd Prolog with Python. The interface should be activated by consulting the python lybrary. It immediately boots a Python image. To best define the interface, one has to address two opposite goals: - make it as similar to python as possible - make all embedded language interfaces (python, R, Java) as similar as possible. Currently, YAP supports the following translation: - numbers -> identical -> */ /************************************************************************************************************ Python interface Data types are Python Prolog string atoms numbers numbers lists lists tuples t(...) generic objs __pointer__(Address) $var refers to the attribute __main__.var *************************************************************************************************************/ :- use_module(library(shlib)). :- use_module(library(lists)). :- use_module(library(apply_macros)). :- use_module(library(charsio)). :- dynamic python_mref_cache/2, python_obj_cache/2. :- multifile user:(<-)/2. := F :- python(F,_). V := F :- var(V), !, python(F,V). A := F :- python(F, F1), python_assign(A, F1). user:( V <- F ) :- V := F. user:((<- F)) :- <- F. python_import(Module) :- python_do_import(Module, _). python_do_import(Module, MRef) :- python_mref_cache(Module, MRef), !. python_do_import(Module, MRef) :- python_import(Module, MRef), assert( python_mref_cache(Module, MRef) ). fetch_module(M:E, M1, E1, MRef) :- atom(M), python_import(M, MRef0), module_extend(M, E, M1, E1, MRef0, MRef). % % extend the module as much as we can. % module_extend(M0, M:E, MF, EF, _MRef0, MRef) :- atom(M), atom_concat([M0,'.',M], MM), python_import(MM, MRef1), !, module_extend(MM, E, MF, EF, MRef1, MRef). module_extend(M0, M.E, MF, EF, _MRef0, MRef) :- MM = M0.M, python_import(MM, MRef1), !, module_extend(MM, E, MF, EF, MRef1, MRef). module_extend(M, E, M, E, MRef, MRef). object_prefix('__obj__'(_)). object_prefix('$'(_)). object_prefix('__obj__'(_):_). object_prefix('$'(_):_). object_prefix('__obj__'(_)._). object_prefix('$'(_)._). % from an exp take an object, and its corresponding Prolog representation descend_exp(V, _Obj, _F, _S) :- var(V), !, throw(error(instantiation_error,_)). descend_exp(Exp, Obj, F, S) :- object_prefix(Exp), !, python_field(Exp, Obj, F, S). descend_exp(Exp, Obj, F, S) :- python_mref_cache(_, MObj), python_field(MObj:Exp, Obj, F, S), !. descend_exp(Mod:Exp, Obj, F, S) :- atom(Mod), python_import(Mod, MObj), python_field(MObj:Exp, Obj, F, S), !. descend_exp(Mod.Exp, Obj, F, S) :- atom(Mod), python_import(Mod, MObj), python_field(MObj:Exp, Obj, F, S), !. python_class(Obj) :- python_obj_cache(inspect:isclass(_), F), python_apply(F, isclass(Obj), {}, true). process_obj(Obj, _, S, Obj, NS, Dict) :- python_callable(Obj), !, python_check_args(S, NS, Dict). process_obj(Obj, _, S, FObj, NS, Dict) :- python_class(Obj), descend_object(Obj:'__init__', FObj, _, _), python_check_args(S, NS, Dict). python_eval_term(Obj, Obj) :- var(Obj), !. python_eval_term('__obj__'(Obj), '__obj__'(Obj)) :- !. python_eval_term($Name, Obj) :- !, python_is($Name, Obj). python_eval_term([H|T], NL) :- is_list(T), !, maplist( python_eval_term, [H|T], NL). python_eval_term(N, N) :- atomic(N), !. python_eval_term(N, N) :- string(N), !. python_eval_term(Exp, O) :- descend_exp(Exp, Obj, _Old, S), !, (functor(S, _, 0) -> O = Obj ; python_check_args(S, NS, Dict), python_apply(Obj, NS, Dict, O) ). python_eval_term(S, O) :- python_check_args(S, NS, {}), python_is(NS, O). python_check_args(Exp, t, {}) :- Exp =.. [_,V], var(V), !. python_check_args(Exp, NExp, Dict) :- functor(Exp, _, Arity), arg(Arity, Exp, A), nonvar(A), A = (_=_), !, Exp =.. [_F|LArgs], match_args(LArgs, NLArgs, Dict), NExp =.. [t|NLArgs]. python_check_args(Exp, NExp, {}) :- Exp =.. [F|L], maplist(python_eval_term, L, LF), NExp =.. [F|LF]. % in case it is __init__ from __new__ splice_class(Ref, Ref, ArgNames, ArgNames) :- !. splice_class(_FRef, _Ref, [_|ArgNames], ArgNames). match_args([], [], {}). match_args([V=A|LArgs], [], Dict) :- !, match_named_args([V=A|LArgs], Map), map_to_dict(Map, Dict). match_args([A|LArgs], [VA|NLArgs], Dict) :- python_eval_term(A, VA), match_args(LArgs, NLArgs, Dict). match_named_args([], []). match_named_args([K=A|LArgs], [K=VA|Map]) :- python_eval_term(A, VA), match_named_args(LArgs, Map). map_to_dict([X=V], {X:V}) :- !. map_to_dict([X=V|Map], {X:V,NDict}) :- map_to_dict(Map, {NDict}). match_from_anames([K|_ArgNames], K, VA, [_|Defaults], [VA|Defaults]) :- !. match_from_anames([_|ArgNames], K, VA, [V|Defaults], [V|NDefaults]) :- match_from_anames(ArgNames, K, VA, Defaults, NDefaults). fetch_args(FRef, Args, Kwd, Defaults) :- FRef = '__obj__'(_), !, %python_mref_cache('inspect', M), python_obj_cache(inspect:getargspec(_), F), python_apply(F, getargspec(FRef), {}, ExtraArgs), ExtraArgs=t(Args, _, Kwd, Defaults). fetch_args(_, []). python(Obj, Out) :- python_eval_term(Obj, Out). python_command(Cmd) :- python_run_command(Cmd). start_python :- init_python, python_main_module(MRef), assert(python_mref_cache('__main__', MRef)), python_command('import sys'), python_import('inspect'), python_mref_cache(inspect, InspRef), python_field(InspRef:isclass(_), IsClass, _, _), assert(python_obj_cache(inspect:isclass(_), IsClass)), python_field(InspRef:getargspec(_), GetArgSpec, _, _), assert(python_obj_cache(inspect:getargspec(_), GetArgSpec)), at_halt(end_python). add_cwd_to_python :- unix(getcwd(Dir)), atom_concat(['sys.path.append(\"',Dir,'\")'], Command), python_command(Command), python_command("sys.argv = [\"yap\"]"). % done python_assign(Name, Exp, '$'(Name)) :- python_assign(Name, Exp). :- initialization( use_foreign_library(foreign(libpython)), now ). :- initialization(start_python, now). :- initialization(add_cwd_to_python).