/* Part of SWI-Prolog
Author: Jan Wielemaker
E-mail: J.Wielemaker@vu.nl
WWW: http://www.swi-prolog.org
Copyright (c) 2005-2018, University of Amsterdam
VU University Amsterdam
CWI, Amsterdam
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/
:- module(prolog_clause,
[ clause_info/4, % +ClauseRef, -File, -TermPos, -VarNames
clause_info/5, % +ClauseRef, -File, -TermPos, -VarNames,
% +Options
initialization_layout/4, % +SourceLoc, +Goal, -Term, -TermPos
predicate_name/2, % +Head, -Name
clause_name/2 % +ClauseRef, -Name
]).
:- use_module(library(lists), [append/3]).
:- use_module(library(occurs), [sub_term/2]).
:- use_module(library(debug)).
:- use_module(library(option)).
:- use_module(library(listing)).
:- use_module(library(prolog_source)).
:- public % called from library(trace/clause)
unify_term/2,
make_varnames/5,
do_make_varnames/3.
:- multifile
unify_goal/5, % +Read, +Decomp, +M, +Pos, -Pos
unify_clause_hook/5,
make_varnames_hook/5,
open_source/2. % +Input, -Stream
:- predicate_options(prolog_clause:clause_info/5, 5,
[ head(-any),
body(-any),
variable_names(-list)
]).
/** <module> Get detailed source-information about a clause
This module started life as part of the GUI tracer. As it is generally
useful for debugging purposes it has moved to the general Prolog
library.
The tracer library library(trace/clause) adds caching and dealing with
dynamic predicates using listing to XPCE objects to this. Note that
clause_info/4 as below can be slow.
*/
%! clause_info(+ClauseRef, -File, -TermPos, -VarOffsets) is semidet.
%! clause_info(+ClauseRef, -File, -TermPos, -VarOffsets, +Options) is semidet.
%
% Fetches source information for the given clause. File is the
% file from which the clause was loaded. TermPos describes the
% source layout in a format compatible to the subterm_positions
% option of read_term/2. VarOffsets provides access to the
% variable allocation in a stack-frame. See make_varnames/5 for
% details.
%
% Note that positions are _|character positions|_, i.e., _not_
% bytes. Line endings count as a single character, regardless of
% whether the actual ending is =|\n|= or =|\r\n|_.
%
% Defined options are:
%
% * variable_names(-Names)
% Unify Names with the variable names list (Name=Var) as
% returned by read_term/3. This argument is intended for
% reporting source locations and refactoring based on
% analysis of the compiled code.
clause_info(ClauseRef, File, TermPos, NameOffset) :-
clause_info(ClauseRef, File, TermPos, NameOffset, []).
clause_info(ClauseRef, File, TermPos, NameOffset, Options) :-
( debugging(clause_info)
-> clause_name(ClauseRef, Name),
debug(clause_info, 'clause_info(~w) (~w)... ',
[ClauseRef, Name])
; true
),
clause_property(ClauseRef, file(File)),
File \== user, % loaded using ?- [user].
'$clause'(Head0, Body, ClauseRef, VarOffset),
option(head(Head0), Options, _),
option(body(Body), Options, _),
( module_property(Module, file(File))
-> true
; strip_module(user:Head0, Module, _)
),
unqualify(Head0, Module, Head),
( Body == true
-> DecompiledClause = Head
; DecompiledClause = (Head :- Body)
),
clause_property(ClauseRef, line_count(LineNo)),
debug(clause_info, 'from ~w:~d ... ', [File, LineNo]),
read_term_at_line(File, LineNo, Module, Clause, TermPos0, VarNames),
option(variable_names(VarNames), Options, _),
debug(clause_info, 'read ...', []),
unify_clause(Clause, DecompiledClause, Module, TermPos0, TermPos),
debug(clause_info, 'unified ...', []),
make_varnames(Clause, DecompiledClause, VarOffset, VarNames, NameOffset),
debug(clause_info, 'got names~n', []),
!.
unqualify(Module:Head, Module, Head) :-
!.
unqualify(Head, _, Head).
%! unify_term(+T1, +T2)
%
% Unify the two terms, where T2 is created by writing the term and
% reading it back in, but be aware that rounding problems may
% cause floating point numbers not to unify. Also, if the initial
% term has a string object, it is written as "..." and read as a
% code-list. We compensate for that.
%
% NOTE: Called directly from library(trace/clause) for the GUI
% tracer.
unify_term(X, X) :- !.
unify_term(X1, X2) :-
compound(X1),
compound(X2),
functor(X1, F, Arity),
functor(X2, F, Arity),
!,
unify_args(0, Arity, X1, X2).
unify_term(X, Y) :-
float(X), float(Y),
!.
unify_term(X, Y) :-
string(X),
is_list(Y),
string_codes(X, Y),
!.
unify_term(_, Y) :-
Y == '...',
!. % elipses left by max_depth
unify_term(_:X, Y) :-
unify_term(X, Y),
!.
unify_term(X, _:Y) :-
unify_term(X, Y),
!.
unify_term(X, Y) :-
format('[INTERNAL ERROR: Diff:~n'),
portray_clause(X),
format('~N*** <->~n'),
portray_clause(Y),
break.
unify_args(N, N, _, _) :- !.
unify_args(I, Arity, T1, T2) :-
A is I + 1,
arg(A, T1, A1),
arg(A, T2, A2),
unify_term(A1, A2),
unify_args(A, Arity, T1, T2).
%! read_term_at_line(+File, +Line, +Module,
%! -Clause, -TermPos, -VarNames) is semidet.
%
% Read a term from File at Line.
read_term_at_line(File, Line, Module, Clause, TermPos, VarNames) :-
setup_call_cleanup(
'$push_input_context'(clause_info),
read_term_at_line_2(File, Line, Module, Clause, TermPos, VarNames),
'$pop_input_context').
read_term_at_line_2(File, Line, Module, Clause, TermPos, VarNames) :-
catch(try_open_source(File, In), error(_,_), fail),
set_stream(In, newline(detect)),
call_cleanup(
read_source_term_at_location(
In, Clause,
[ line(Line),
module(Module),
subterm_positions(TermPos),
variable_names(VarNames)
]),
close(In)).
%! open_source(+File, -Stream) is semidet.
%
% Hook into clause_info/5 that opens the stream holding the source
% for a specific clause. Thus, the query must succeed. The default
% implementation calls open/3 on the `File` property.
%
% ==
% clause_property(ClauseRef, file(File)),
% prolog_clause:open_source(File, Stream)
% ==
:- public try_open_source/2. % used by library(prolog_breakpoints).
try_open_source(File, In) :-
open_source(File, In),
!.
try_open_source(File, In) :-
open(File, read, In).
%! make_varnames(+ReadClause, +DecompiledClause,
%! +Offsets, +Names, -Term) is det.
%
% Create a Term varnames(...) where each argument contains the name
% of the variable at that offset. If the read Clause is a DCG rule,
% name the two last arguments <DCG_list> and <DCG_tail>
%
% This predicate calles the multifile predicate
% make_varnames_hook/5 with the same arguments to allow for user
% extensions. Extending this predicate is needed if a compiler
% adds additional arguments to the clause head that must be made
% visible in the GUI tracer.
%
% @param Offsets List of Offset=Var
% @param Names List of Name=Var
make_varnames(ReadClause, DecompiledClause, Offsets, Names, Term) :-
make_varnames_hook(ReadClause, DecompiledClause, Offsets, Names, Term),
!.
make_varnames((Head --> _Body), _, Offsets, Names, Bindings) :-
!,
functor(Head, _, Arity),
In is Arity,
memberchk(In=IVar, Offsets),
Names1 = ['<DCG_list>'=IVar|Names],
Out is Arity + 1,
memberchk(Out=OVar, Offsets),
Names2 = ['<DCG_tail>'=OVar|Names1],
make_varnames(xx, xx, Offsets, Names2, Bindings).
make_varnames(_, _, Offsets, Names, Bindings) :-
length(Offsets, L),
functor(Bindings, varnames, L),
do_make_varnames(Offsets, Names, Bindings).
do_make_varnames([], _, _).
do_make_varnames([N=Var|TO], Names, Bindings) :-
( find_varname(Var, Names, Name)
-> true
; Name = '_'
),
AN is N + 1,
arg(AN, Bindings, Name),
do_make_varnames(TO, Names, Bindings).
find_varname(Var, [Name = TheVar|_], Name) :-
Var == TheVar,
!.
find_varname(Var, [_|T], Name) :-
find_varname(Var, T, Name).
%! unify_clause(+Read, +Decompiled, +Module, +ReadTermPos,
%! -RecompiledTermPos).
%
% What you read isn't always what goes into the database. The task
% of this predicate is to establish the relation between the term
% read from the file and the result from decompiling the clause.
%
% This predicate calls the multifile predicate unify_clause_hook/5
% with the same arguments to support user extensions.
%
% @tbd This really must be more flexible, dealing with much
% more complex source-translations, falling back to a
% heuristic method locating as much as possible.
unify_clause(Read, Read, _, TermPos, TermPos) :- !.
% XPCE send-methods
unify_clause(Read, Decompiled, Module, TermPos0, TermPos) :-
unify_clause_hook(Read, Decompiled, Module, TermPos0, TermPos),
!.
unify_clause(:->(Head, Body), (PlHead :- PlBody), M, TermPos0, TermPos) :-
!,
pce_method_clause(Head, Body, PlHead, PlBody, M, TermPos0, TermPos).
% XPCE get-methods
unify_clause(:<-(Head, Body), (PlHead :- PlBody), M, TermPos0, TermPos) :-
!,
pce_method_clause(Head, Body, PlHead, PlBody, M, TermPos0, TermPos).
% Unit test clauses
unify_clause((TH :- Body),
(_:'unit body'(_, _) :- !, Body), _,
TP0, TP) :-
( TH = test(_,_)
; TH = test(_)
),
!,
TP0 = term_position(F,T,FF,FT,[HP,BP]),
TP = term_position(F,T,FF,FT,[HP,term_position(0,0,0,0,[FF-FT,BP])]).
% module:head :- body
unify_clause((Head :- Read),
(Head :- _M:Compiled), Module, TermPos0, TermPos) :-
unify_clause((Head :- Read), (Head :- Compiled), Module, TermPos0, TermPos1),
TermPos1 = term_position(TA,TZ,FA,FZ,[PH,PB]),
TermPos = term_position(TA,TZ,FA,FZ,
[ PH,
term_position(0,0,0,0,[0-0,PB])
]).
% DCG rules
unify_clause(Read, Compiled1, Module, TermPos0, TermPos) :-
Read = (_ --> Terminal, _),
is_list(Terminal),
ci_expand(Read, Compiled2, Module, TermPos0, TermPos1),
Compiled2 = (DH :- _),
functor(DH, _, Arity),
DArg is Arity - 1,
append(Terminal, _Tail, List),
arg(DArg, DH, List),
TermPos1 = term_position(F,T,FF,FT,[ HP,
term_position(_,_,_,_,[_,BP])
]),
!,
TermPos2 = term_position(F,T,FF,FT,[ HP, BP ]),
match_module(Compiled2, Compiled1, Module, TermPos2, TermPos).
% general term-expansion
unify_clause(Read, Compiled1, Module, TermPos0, TermPos) :-
ci_expand(Read, Compiled2, Module, TermPos0, TermPos1),
match_module(Compiled2, Compiled1, Module, TermPos1, TermPos).
% I don't know ...
unify_clause(_, _, _, _, _) :-
debug(clause_info, 'Could not unify clause', []),
fail.
unify_clause_head(H1, H2) :-
strip_module(H1, _, H),
strip_module(H2, _, H).
ci_expand(Read, Compiled, Module, TermPos0, TermPos) :-
catch(setup_call_cleanup(
( set_xref_flag(OldXRef),
'$set_source_module'(Old, Module)
),
expand_term(Read, TermPos0, Compiled, TermPos),
( '$set_source_module'(Old),
set_prolog_flag(xref, OldXRef)
)),
E,
expand_failed(E, Read)).
set_xref_flag(Value) :-
current_prolog_flag(xref, Value),
!,
set_prolog_flag(xref, true).
set_xref_flag(false) :-
create_prolog_flag(xref, true, [type(boolean)]).
match_module((H1 :- B1), (H2 :- B2), Module, Pos0, Pos) :-
!,
unify_clause_head(H1, H2),
unify_body(B1, B2, Module, Pos0, Pos).
match_module((H1 :- B1), H2, _Module, Pos0, Pos) :-
B1 == true,
unify_clause_head(H1, H2),
Pos = Pos0,
!.
match_module(H1, H2, _, Pos, Pos) :- % deal with facts
unify_clause_head(H1, H2).
%! expand_failed(+Exception, +Term)
%
% When debugging, indicate that expansion of the term failed.
expand_failed(E, Read) :-
debugging(clause_info),
message_to_string(E, Msg),
debug(clause_info, 'Term-expand ~p failed: ~w', [Read, Msg]),
fail.
%! unify_body(+Read, +Decompiled, +Module, +Pos0, -Pos)
%
% Deal with translations implied by the compiler. For example,
% compiling (a,b),c yields the same code as compiling a,b,c.
%
% Pos0 and Pos still include the term-position of the head.
unify_body(B, C, _, Pos, Pos) :-
B =@= C, B = C,
does_not_dcg_after_binding(B, Pos),
!.
unify_body(R, D, Module,
term_position(F,T,FF,FT,[HP,BP0]),
term_position(F,T,FF,FT,[HP,BP])) :-
ubody(R, D, Module, BP0, BP).
%! does_not_dcg_after_binding(+ReadBody, +ReadPos) is semidet.
%
% True if ReadPos/ReadPos does not contain DCG delayed
% unifications.
%
% @tbd We should pass that we are in a DCG; if we are not there
% is no reason for this test.
does_not_dcg_after_binding(B, Pos) :-
\+ sub_term(brace_term_position(_,_,_), Pos),
\+ (sub_term((Cut,_=_), B), Cut == !),
!.
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Some remarks.
a --> { x, y, z }.
This is translated into "(x,y),z), X=Y" by the DCG translator, after
which the compiler creates "a(X,Y) :- x, y, z, X=Y".
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
%! unify_goal(+Read, +Decompiled, +Module,
%! +TermPosRead, -TermPosDecompiled) is semidet.
%
% This hook is called to fix up source code manipulations that
% result from goal expansions.
%! ubody(+Read, +Decompiled, +Module, +TermPosRead, -TermPosForDecompiled)
%
% @param Read Clause read _after_ expand_term/2
% @param Decompiled Decompiled clause
% @param Module Load module
% @param TermPosRead Sub-term positions of source
ubody(B, DB, _, P, P) :-
var(P), % TBD: Create compatible pos term?
!,
B = DB.
ubody(B, C, _, P, P) :-
B =@= C, B = C,
does_not_dcg_after_binding(B, P),
!.
ubody(X0, X, M, parentheses_term_position(_, _, P0), P) :-
!,
ubody(X0, X, M, P0, P).
ubody(X, call(X), _, % X = call(X)
Pos,
term_position(From, To, From, To, [Pos])) :-
!,
arg(1, Pos, From),
arg(2, Pos, To).
ubody(B, D, _, term_position(_,_,_,_,[_,RP]), TPOut) :-
nonvar(B), B = M:R,
ubody(R, D, M, RP, TPOut).
ubody(B0, B, M,
brace_term_position(F,T,A0),
Pos) :-
B0 = (_,_=_),
!,
T1 is T - 1,
ubody(B0, B, M,
term_position(F,T,
F,T,
[A0,T1-T]),
Pos).
ubody(B0, B, M,
brace_term_position(F,T,A0),
term_position(F,T,F,T,[A])) :-
!,
ubody(B0, B, M, A0, A).
ubody(C0, C, M, P0, P) :-
nonvar(C0), nonvar(C),
C0 = (_,_), C = (_,_),
!,
conj(C0, P0, GL, PL),
mkconj(C, M, P, GL, PL).
ubody(Read, Decompiled, Module, TermPosRead, TermPosDecompiled) :-
unify_goal(Read, Decompiled, Module, TermPosRead, TermPosDecompiled),
!.
ubody(X0, X, M,
term_position(F,T,FF,TT,PA0),
term_position(F,T,FF,TT,PA)) :-
meta(M, X0, S),
!,
X0 =.. [_|A0],
X =.. [_|A],
S =.. [_|AS],
ubody_list(A0, A, AS, M, PA0, PA).
ubody(X0, X, M,
term_position(F,T,FF,TT,PA0),
term_position(F,T,FF,TT,PA)) :-
expand_goal(X0, X, M, PA0, PA).
% 5.7.X optimizations
ubody(_=_, true, _, % singleton = Any
term_position(F,T,_FF,_TT,_PA),
F-T) :- !.
ubody(_==_, fail, _, % singleton/firstvar == Any
term_position(F,T,_FF,_TT,_PA),
F-T) :- !.
ubody(A1=B1, B2=A2, _, % Term = Var --> Var = Term
term_position(F,T,FF,TT,[PA1,PA2]),
term_position(F,T,FF,TT,[PA2,PA1])) :-
var(B1), var(B2),
(A1==B1) =@= (B2==A2),
!,
A1 = A2, B1=B2.
ubody(A1==B1, B2==A2, _, % const == Var --> Var == const
term_position(F,T,FF,TT,[PA1,PA2]),
term_position(F,T,FF,TT,[PA2,PA1])) :-
var(B1), var(B2),
(A1==B1) =@= (B2==A2),
!,
A1 = A2, B1=B2.
ubody(A is B - C, A is B + C2, _, Pos, Pos) :-
integer(C),
C2 =:= -C,
!.
ubody_list([], [], [], _, [], []).
ubody_list([G0|T0], [G|T], [AS|ASL], M, [PA0|PAT0], [PA|PAT]) :-
ubody_elem(AS, G0, G, M, PA0, PA),
ubody_list(T0, T, ASL, M, PAT0, PAT).
ubody_elem(0, G0, G, M, PA0, PA) :-
!,
ubody(G0, G, M, PA0, PA).
ubody_elem(_, G, G, _, PA, PA).
conj(Goal, Pos, GoalList, PosList) :-
conj(Goal, Pos, GoalList, [], PosList, []).
conj((A,B), term_position(_,_,_,_,[PA,PB]), GL, TG, PL, TP) :-
!,
conj(A, PA, GL, TGA, PL, TPA),
conj(B, PB, TGA, TG, TPA, TP).
conj((A,B), brace_term_position(_,T,PA), GL, TG, PL, TP) :-
B = (_=_),
!,
conj(A, PA, GL, TGA, PL, TPA),
T1 is T - 1,
conj(B, T1-T, TGA, TG, TPA, TP).
conj(A, parentheses_term_position(_,_,Pos), GL, TG, PL, TP) :-
nonvar(Pos),
!,
conj(A, Pos, GL, TG, PL, TP).
conj((!,(S=SR)), F-T, [!,S=SR|TG], TG, [F-T,F1-T1|TP], TP) :-
F1 is F+1,
T1 is T+1.
conj(A, P, [A|TG], TG, [P|TP], TP).
mkconj(Goal, M, Pos, GoalList, PosList) :-
mkconj(Goal, M, Pos, GoalList, [], PosList, []).
mkconj(Conj, M, term_position(0,0,0,0,[PA,PB]), GL, TG, PL, TP) :-
nonvar(Conj),
Conj = (A,B),
!,
mkconj(A, M, PA, GL, TGA, PL, TPA),
mkconj(B, M, PB, TGA, TG, TPA, TP).
mkconj(A0, M, P0, [A|TG], TG, [P|TP], TP) :-
ubody(A, A0, M, P, P0).
/*******************************
* PCE STUFF (SHOULD MOVE) *
*******************************/
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
<method>(Receiver, ... Arg ...) :->
Body
mapped to:
send_implementation(Id, <method>(...Arg...), Receiver)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
pce_method_clause(Head, Body, M:PlHead, PlBody, _, TermPos0, TermPos) :-
!,
pce_method_clause(Head, Body, PlBody, PlHead, M, TermPos0, TermPos).
pce_method_clause(Head, Body,
send_implementation(_Id, Msg, Receiver), PlBody,
M, TermPos0, TermPos) :-
!,
debug(clause_info, 'send method ...', []),
arg(1, Head, Receiver),
functor(Head, _, Arity),
pce_method_head_arguments(2, Arity, Head, Msg),
debug(clause_info, 'head ...', []),
pce_method_body(Body, PlBody, M, TermPos0, TermPos).
pce_method_clause(Head, Body,
get_implementation(_Id, Msg, Receiver, Result), PlBody,
M, TermPos0, TermPos) :-
!,
debug(clause_info, 'get method ...', []),
arg(1, Head, Receiver),
debug(clause_info, 'receiver ...', []),
functor(Head, _, Arity),
arg(Arity, Head, PceResult),
debug(clause_info, '~w?~n', [PceResult = Result]),
pce_unify_head_arg(PceResult, Result),
Ar is Arity - 1,
pce_method_head_arguments(2, Ar, Head, Msg),
debug(clause_info, 'head ...', []),
pce_method_body(Body, PlBody, M, TermPos0, TermPos).
pce_method_head_arguments(N, Arity, Head, Msg) :-
N =< Arity,
!,
arg(N, Head, PceArg),
PLN is N - 1,
arg(PLN, Msg, PlArg),
pce_unify_head_arg(PceArg, PlArg),
debug(clause_info, '~w~n', [PceArg = PlArg]),
NextArg is N+1,
pce_method_head_arguments(NextArg, Arity, Head, Msg).
pce_method_head_arguments(_, _, _, _).
pce_unify_head_arg(V, A) :-
var(V),
!,
V = A.
pce_unify_head_arg(A:_=_, A) :- !.
pce_unify_head_arg(A:_, A).
% pce_method_body(+SrcBody, +DbBody, +M, +TermPos0, -TermPos
%
% Unify the body of an XPCE method. Goal-expansion makes this
% rather tricky, especially as we cannot call XPCE's expansion
% on an isolated method.
%
% TermPos0 is the term-position term of the whole clause!
%
% Further, please note that the body of the method-clauses reside
% in another module than pce_principal, and therefore the body
% starts with an I_CONTEXT call. This implies we need a
% hypothetical term-position for the module-qualifier.
pce_method_body(A0, A, M, TermPos0, TermPos) :-
TermPos0 = term_position(F, T, FF, FT,
[ HeadPos,
BodyPos0
]),
TermPos = term_position(F, T, FF, FT,
[ HeadPos,
term_position(0,0,0,0, [0-0,BodyPos])
]),
pce_method_body2(A0, A, M, BodyPos0, BodyPos).
pce_method_body2(::(_,A0), A, M, TermPos0, TermPos) :-
!,
TermPos0 = term_position(_, _, _, _, [_Cmt,BodyPos0]),
TermPos = BodyPos,
expand_goal(A0, A, M, BodyPos0, BodyPos).
pce_method_body2(A0, A, M, TermPos0, TermPos) :-
A0 =.. [Func,B0,C0],
control_op(Func),
!,
A =.. [Func,B,C],
TermPos0 = term_position(F, T, FF, FT,
[ BP0,
CP0
]),
TermPos = term_position(F, T, FF, FT,
[ BP,
CP
]),
pce_method_body2(B0, B, M, BP0, BP),
expand_goal(C0, C, M, CP0, CP).
pce_method_body2(A0, A, M, TermPos0, TermPos) :-
expand_goal(A0, A, M, TermPos0, TermPos).
control_op(',').
control_op((;)).
control_op((->)).
control_op((*->)).
/*******************************
* EXPAND_GOAL SUPPORT *
*******************************/
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
With the introduction of expand_goal, it is increasingly hard to relate
the clause from the database to the actual source. For one thing, we do
not know the compilation module of the clause (unless we want to
decompile it).
Goal expansion can translate goals into control-constructs, multiple
clauses, or delete a subgoal.
To keep track of the source-locations, we have to redo the analysis of
the clause as defined in init.pl
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
expand_goal(G, call(G), _, P, term_position(0,0,0,0,[P])) :-
var(G),
!.
expand_goal(G, G, _, P, P) :-
var(G),
!.
expand_goal(M0, M, Module, P0, P) :-
meta(Module, M0, S),
!,
P0 = term_position(F,T,FF,FT,PL0),
P = term_position(F,T,FF,FT,PL),
functor(M0, Functor, Arity),
functor(M, Functor, Arity),
expand_meta_args(PL0, PL, 1, S, Module, M0, M).
expand_goal(A, B, Module, P0, P) :-
goal_expansion(A, B0, P0, P1),
!,
expand_goal(B0, B, Module, P1, P).
expand_goal(A, A, _, P, P).
expand_meta_args([], [], _, _, _, _, _).
expand_meta_args([P0|T0], [P|T], I, S, Module, M0, M) :-
arg(I, M0, A0),
arg(I, M, A),
arg(I, S, AS),
expand_arg(AS, A0, A, Module, P0, P),
NI is I + 1,
expand_meta_args(T0, T, NI, S, Module, M0, M).
expand_arg(0, A0, A, Module, P0, P) :-
!,
expand_goal(A0, A, Module, P0, P).
expand_arg(_, A, A, _, P, P).
meta(M, G, S) :- predicate_property(M:G, meta_predicate(S)).
goal_expansion(send(R, Msg), send_class(R, _, SuperMsg), P, P) :-
compound(Msg),
Msg =.. [send_super, Selector | Args],
!,
SuperMsg =.. [Selector|Args].
goal_expansion(get(R, Msg, A), get_class(R, _, SuperMsg, A), P, P) :-
compound(Msg),
Msg =.. [get_super, Selector | Args],
!,
SuperMsg =.. [Selector|Args].
goal_expansion(send_super(R, Msg), send_class(R, _, Msg), P, P).
goal_expansion(get_super(R, Msg, V), get_class(R, _, Msg, V), P, P).
goal_expansion(SendSuperN, send_class(R, _, Msg), P, P) :-
compound(SendSuperN),
compound_name_arguments(SendSuperN, send_super, [R,Sel|Args]),
Msg =.. [Sel|Args].
goal_expansion(SendN, send(R, Msg), P, P) :-
compound(SendN),
compound_name_arguments(SendN, send, [R,Sel|Args]),
atom(Sel), Args \== [],
Msg =.. [Sel|Args].
goal_expansion(GetSuperN, get_class(R, _, Msg, Answer), P, P) :-
compound(GetSuperN),
compound_name_arguments(GetSuperN, get_super, [R,Sel|AllArgs]),
append(Args, [Answer], AllArgs),
Msg =.. [Sel|Args].
goal_expansion(GetN, get(R, Msg, Answer), P, P) :-
compound(GetN),
compound_name_arguments(GetN, get, [R,Sel|AllArgs]),
append(Args, [Answer], AllArgs),
atom(Sel), Args \== [],
Msg =.. [Sel|Args].
goal_expansion(G0, G, P, P) :-
user:goal_expansion(G0, G), % TBD: we need the module!
G0 \== G. % \=@=?
/*******************************
* INITIALIZATION *
*******************************/
%! initialization_layout(+SourceLocation, ?InitGoal,
%! -ReadGoal, -TermPos) is semidet.
%
% Find term-layout of :- initialization directives.
initialization_layout(File:Line, M:Goal0, Goal, TermPos) :-
read_term_at_line(File, Line, M, Directive, DirectivePos, _),
Directive = (:- initialization(ReadGoal)),
DirectivePos = term_position(_, _, _, _, [InitPos]),
InitPos = term_position(_, _, _, _, [GoalPos]),
( ReadGoal = M:_
-> Goal = M:Goal0
; Goal = Goal0
),
unify_body(ReadGoal, Goal, M, GoalPos, TermPos),
!.
/*******************************
* PRINTABLE NAMES *
*******************************/
:- module_transparent
predicate_name/2.
:- multifile
user:prolog_predicate_name/2,
user:prolog_clause_name/2.
hidden_module(user).
hidden_module(system).
hidden_module(pce_principal). % should be config
hidden_module(Module) :- % SWI-Prolog specific
import_module(Module, system).
thaffix(1, st) :- !.
thaffix(2, nd) :- !.
thaffix(_, th).
%! predicate_name(:Head, -PredName:string) is det.
%
% Describe a predicate as [Module:]Name/Arity.
predicate_name(Predicate, PName) :-
strip_module(Predicate, Module, Head),
( user:prolog_predicate_name(Module:Head, PName)
-> true
; functor(Head, Name, Arity),
( hidden_module(Module)
-> format(string(PName), '~q/~d', [Name, Arity])
; format(string(PName), '~q:~q/~d', [Module, Name, Arity])
)
).
%! clause_name(+Ref, -Name)
%
% Provide a suitable description of the indicated clause.
clause_name(Ref, Name) :-
user:prolog_clause_name(Ref, Name),
!.
clause_name(Ref, Name) :-
nth_clause(Head, N, Ref),
!,
predicate_name(Head, PredName),
thaffix(N, Th),
format(string(Name), '~d-~w clause of ~w', [N, Th, PredName]).
clause_name(Ref, Name) :-
clause_property(Ref, erased),
!,
clause_property(Ref, predicate(M:PI)),
format(string(Name), 'erased clause from ~q', [M:PI]).
clause_name(_, '<meta-call>').