This repository has been archived on 2023-08-20. You can view files and clone it, but cannot push or open issues or pull requests.
yap-6.3/packages/meld/meldc.yap
Vítor Santos Costa ef3a5754e6 syntax errors
2014-08-06 10:26:03 -05:00

376 lines
9.6 KiB
Prolog

%
% A compiler for Meld programs
% can understand aggregates.
%
:- module(meld_compiler,
[
mcompile/1,
input_graph/1,
run/1
]).
:- use_module(meldi,
[
push/1,
first/2,
min/3,
max/3,
sum/3
]).
:- use_module(meld).
:- use_module(library(meld)).
:- use_module(library(terms), [
variable_in_term/2
]).
:- use_module(library(ordsets), [
ord_subset/2,
ord_union/3
]).
:- dynamic meld_constants:const/2.
mcompile(Program) :-
open(Program, read, P),
init_mcompile(Program),
repeat,
read_term(P, Term, [variable_names(Vars), module(meld_compiler)]),
(
Term == end_of_file
->
!,
close(P)
;
mcompile(Term, Program, Vars),
fail
).
init_mcompile(Program) :-
retractall(type(_, _, Program, _)).
mcompile(type(T), Program, Vars) :-
ground_term(T, Vars),
type_declaration(T, Program), !.
mcompile(const(T=V), _Program, Vars) :-
ground_term(T, Vars),
const_declaration(T, V), !.
mcompile((Head :- Body), _, _Vars) :-
rule(Head, Body).
type_declaration(extensional(T), Program) :- !,
functor(T, Na, Arity),
functor(NT, Na, Arity),
assert(meld_topdown:extensional(NT, Na, Arity)),
type_declaration(T, Program).
type_declaration(logical_neighbor(T), Program) :- !,
type_declaration(T, Program).
type_declaration(persistent(T), Program) :- !,
type_declaration(T, Program).
type_declaration(extern(T), Program) :- !,
type_declaration(T, Program).
type_declaration(T, _) :-
functor(T, N, A),
dynamic(meld_program:N/A),
fail.
type_declaration(T, Program) :-
T =.. [P|Args],
check_aggregate(Args, 1, NewArgs, Aggregation, Arg),
!,
NT =.. [P|NewArgs],
assert_type(NT, Program, aggregation(Aggregation, Arg)).
type_declaration(T, Program) :-
assert_type(T, Program, horn).
assert_type(NT, Program, Agg) :-
functor(NT, Na, Ar),
functor(Spec, Na, Ar),
assert(type(Spec, NT, Program, Agg)).
const_declaration(C,V) :- !,
( atom(C) -> true ; throw(type_error(atom,C),const(C=V))),
( number(V) -> true ; throw(type_error(number,V),const(C=V))),
assert(meld_constants:const(C, V)).
check_aggregate([first(Type)|Args], I, [Type|Args], first, I) :- !.
check_aggregate([max(Type)|Args], I, [Type|Args], max, I) :- !.
check_aggregate([min(Type)|Args], I, [Type|Args], min, I) :- !.
check_aggregate([sum(Type)|Args], I, [Type|Args], sum, I) :- !.
check_aggregate([Type|Args], I, [Type|NewArgs], Agg, Arg) :-
atom(Type),
I1 is I+1,
check_aggregate(Args, I1, NewArgs, Agg, Arg).
ground_term(_, []).
%
% Rule compiler
%
rule(Head, Body) :-
bodytolist(Body, L0, []),
builtins(L0, L, R),
builtins([Head], RLH, []),
join(RLH, NHead, R, []),
compile_goals(L, [], NHead).
builtins([]) --> [].
builtins(G.Gs) -->
builtin(G),
builtins(Gs).
builtin(Res = Op) --> !,
process_constants(Op, Res).
builtin(Goal) -->
process_constants(Goal, NGoal),
[ NGoal ].
process_constants(G, G) -->
{ var(G) }, !.
process_constants(C, V) -->
{ meld_constants:const(C,V) }, !.
process_constants(G, G) -->
{ atomic(G) }, !.
process_constants(to_float(Arg1), NArg1) --> !,
process_constants(Arg1, NArg1).
process_constants(A, NA) -->
{ arithmetic(A, Op, Arg1, Arg2) }, !,
process_constants(Arg1, NArg1),
process_constants(Arg2, NArg2),
{ arithmetic(NExp, Op, NArg1, NArg2) },
[ NA is NExp ].
process_constants(A, NA) -->
{ arithmetic(A, Op, Arg1) }, !,
process_constants(Arg1, NArg1),
{ arithmetic(NExp, Op, NArg1) },
[ NA is NExp ].
process_constants(G, NG) -->
{ G =.. [A|Args] },
process_args(Args, NArgs),
{ NG =.. [A|NArgs] }.
process_args([], []) --> [].
process_args(A.Args, NA.NArgs) -->
process_constants(A, NA),
process_args(Args, NArgs).
join([H0], H0) --> !.
join([H|T], H0) -->
[H],
join(T, H0).
compile_goals([], _, _).
compile_goals([Goal|Goals], Gs, Head) :-
compile_goal(Goal, Goals, Gs, Head),
compile_goals(Goals, [Goal|Gs], Head).
compile_goal(BIP, _Goals, _Gs, _Head) :-
meld_builtin(BIP, _, _), !.
compile_goal((forall G then Do), Goals, Gs, Head) :- !,
% make sure quantified variables are not seen outside
quantified_vars(G,Gs+Goals,NG),
%
% just collect the body into a number of goals
%
collect_body(Gs, [(forall G then Do)|Goals], BLF, BL1),
% make a backup copy for deletion
copy_term(h(Head,BLF,BL1,NG), h(Head,DelBLF,DelBL1,DelNG)),
% add the operation, usually push
extra_head(Head, BL1, []),
% add the delete operation
extra_delete(Head, DelBL1, []),
% reorder builtins
reorder_builtins(NG, BLF, BLF2),
reorder_builtins(DelNG, DelBLF, DelBLF2),
% create the body as a conjunction
listtobody(BLF2, Body),
listtobody(DelBLF2, DelBody),
% done
assert_static(meld_program:(run(NG) :- Body)),
assert_static(meld_program:(run(delete(DelNG)) :- DelBody)).
compile_goal(Goal, Goals, Gs, Head) :-
collect_body(Gs, Goals, BLF, BL1),
copy_term(h(Head,BLF,BL1,Goal), h(Head,DelBLF,DelBL1,DelGoal)),
extra_head(Head, BL1, []),
extra_delete(Head, DelBL1, []),
% reorder builtins
reorder_builtins(Goal, BLF, BLF2),
reorder_builtins(DelGoal, DelBLF, DelBLF2),
listtobody(BLF2, Body),
listtobody(DelBLF2, DelBody),
assert_static(meld_program:(run(Goal) :- Body)),
assert_static(meld_program:(run(deleted(DelGoal)) :- DelBody)).
% quantified variables should not leave the scope of the forall.
quantified_vars(G,Extern,NG) :-
term_variables(G, TVs),
copy_term(G+TVs,NG+NTVs),
bind_external(TVs, NTVs, Extern).
bind_external([], [], _).
bind_external(V.TVs, NV.NTVs, Extern) :-
variable_in_term(Extern, V), !,
V = NV,
bind_external(TVs, NTVs, Extern).
bind_external(_.TVs, _.NTVs, Extern) :-
bind_external(TVs, NTVs, Extern).
% a very simple version
%
collect_body([], []) --> [].
collect_body([G|Gs], MGs) -->
process_goal(G),
collect_body(Gs, MGs).
collect_body([], [G|Gs]) -->
process_goal(G),
collect_body([], Gs).
process_goal((forall Goal then Conj)) --> !,
[(Goal, \+ Conj -> fail ; true)].
process_goal( G ) -->
[G].
extra_head(Head) -->
{ type(Head, _, _, horn) },
[push(Head)].
extra_head(Head) -->
{ type(Head, _, _, aggregation(first, Arg)),
freshen(Head, Arg, VHead) },
[ meld_interpreter:first(VHead, Head)].
extra_head(Head) -->
{ type(Head, _, _, aggregation(max, Arg)),
freshen(Head, Arg, VHead) },
[ meld_interpreter:max(VHead, Arg, Head)].
extra_head(Head) -->
{ type(Head, _, _, aggregation(min, Arg)),
freshen(Head, Arg, VHead) },
[ meld_interpreter:min(VHead, Arg, Head)].
extra_head(Head) -->
{ type(Head, _, _, aggregation(sum, Arg)),
freshen(Head, Arg, VHead) },
[ meld_interpreter:sum(VHead, Arg, Head)].
extra_delete(Head) -->
{ type(Head, _, _, horn) },
[meld_interpreter:deleted(Head)].
extra_delete(Head) -->
{ type(Head, _, _, aggregation(first, Arg)),
freshen(Head, Arg, VHead) },
[ meld_interpreter:delete_from_first(VHead, Head)].
extra_delete(Head) -->
{ type(Head, _, _, aggregation(max, Arg)),
freshen(Head, Arg, VHead) },
[ meld_interpreter:delete_from_max(VHead, Arg, Head)].
extra_delete(Head) -->
{ type(Head, _, _, aggregation(min, Arg)),
freshen(Head, Arg, VHead) },
[ meld_interpreter:delete_from_min(VHead, Arg, Head)].
extra_delete(Head) -->
{ type(Head, _, _, aggregation(sum, Arg)),
freshen(Head, Arg, VHead) },
[ meld_interpreter:delete_from_sum(VHead, Arg, Head)].
freshen(Head, Arg, VHead) :-
Head =.. [N|Args],
freshen_arg(Arg, Args, VArgs),
VHead =.. [N|VArgs].
freshen_arg(1, [_|Args], [_|Args]) :- !.
freshen_arg(N, A.Args, A.VArgs) :-
N1 is N-1,
freshen_arg(N1, Args, VArgs).
input_graph(Program) :-
open(Program, read, P),
repeat,
read_term(P, Term, [variable_names(_Vars), module(meld_compiler)]),
(
Term == end_of_file
->
!,
close(P)
;
add_graph_fact(Term),
fail
).
add_graph_fact(Term) :-
push(Term).
bodytolist((G1,G2)) -->
!,
bodytolist(G1),
bodytolist(G2).
bodytolist(G) -->
[G].
listtobody([G], G) :- !.
listtobody([G|GL], (G,Gs)) :-
listtobody(GL, Gs).
reorder_builtins(Head, BLF, BLF2) :-
term_variables(Head, Vs0),
sort(Vs0, Vs),
reorder_term(BLF, Vs, [], BLF2).
% 4 arguments
% list of input goals
% queue of built-ins waiting for execution
% list of current variables
% output variables
%
reorder_term([], _, [], []).
reorder_term(G.Gs, Vs0, Queue, NGs) :-
meld_builtin(G, Is, Os), !,
term_variables(Is, InpVs0),
sort(InpVs0, InpVs),
continue_reorder_term(Gs, G, InpVs, Vs0, Queue, Os, NGs).
reorder_term(G.Gs, Vs0, Queue, G.NGs) :-
term_variables(G, GVs0),
sort(GVs0, GVs),
ord_union(GVs, Vs0, Vs),
wake_queue(Queue, NewQueue, Vs, Vs0, NewQueue, FVs, NGs, NGs0),
reorder_term(Gs, FVs, NewQueue, NGs0).
continue_reorder_term(Gs, G, InpVs, Vs0, Queue, Os, G.NGs) :-
ord_subset(InpVs, Vs0), !,
term_variables(Os, OutVs0),
sort(OutVs0, OutVs),
ord_union(OutVs, Vs0, Vs),
wake_queue(Queue, NewQueue, Vs, Vs0, NewQueue, FVs, NGs, NGs0),
reorder_term(Gs, FVs, NewQueue, NGs0).
continue_reorder_term(Gs, G, InpVs, Vs0, Queue, Os, NGs) :-
term_variables(Os, OutVs0),
sort(OutVs0, OutVs),
reorder_term(Gs, Vs0, q(InpVs, OutVs, G).Queue, NGs).
wake_queue([], _, Vs, _, [], Vs) --> [].
wake_queue(Q.Queue, _, Vs, Vs0, Q.Queue, Vs) --> { Vs == Vs0 }, !.
wake_queue(q(InpVs,OutVs,G).Queue, NewQueue, Vs, Vs0, Queue, FVs) -->
{ ord_subset(InpVs, Vs) }, !,
[G],
{ ord_union(OutVs, Vs, NVs) },
% restart from beginning
wake_queue(NewQueue, NewNewQueue, NVs, Vs0, NewNewQueue, FVs).
wake_queue(Q.Queue, NewQueue, NVs, Vs0, Q.NQueue, FVs) -->
wake_queue(Queue, NewQueue, NVs, Vs0, NQueue, FVs).
meld_builtin(O is I, I, O).
meld_builtin(I1 =< I2, I1-I2, []).
meld_builtin(I1 >= I2, I1-I2, []).
meld_builtin(I1 =:= I2, I1-I2, []).
arithmetic( A+B, (+), A, B).
arithmetic( A-B, (-), A, B).
arithmetic( A*B, (*), A, B).
arithmetic( A/B, (/), A, B).
arithmetic( sin(A), sin, A).
arithmetic( cos(A), cos, A).
arithmetic( tan(A), tan, A).