Rewrite arithmetic expansion

Author: hurufu

src/loader.pl

@@ -43,53 +43,34 @@
     catch(loader:G_0, E, (loader:writeln(exception:E:G_0),throw(E))).
 w(G_0) :-
     writeln(call:G_0), x(G_0), writeln(exit:G_0).
-w(_) :-
-    writeln(done).
 
-%% arithmetic_relation_expanded(?Term, ListDifference).
-%
-% Recursively traverse Term and assemble a list of replacements that make a
-% valid aruthmetic relation.
+%% arithmetic_expansion(+Type, ?Term, -ExpandedTerm, ListDifference).
 %
 % Hand-expanded DCG, because library(dcgs) isn't available during goal expansion.
-arithmetic_relation_expanded(T, L1-L2) :-
-    maplist(loader:elaborate(F/2), [T,R], [Ts,Rs]),
-    memberchk(F, [is,>,<,>=,=<,=:=,=\=]),
-    next(ok(Ts,Rs), L1-[R|L2]).
-
-%% next(+Marker, ListDifference).
-%
-% Describes needed replacements according to `Marker`.
-next(nok(T,R), [T=R|L]-L).
-next(ok([],[]), L-L).
-next(ok([T0|Ts],[R0|Rs]), L1-L3) :-
-    arithmetic_function_expanded(T0, R0, L1-L2), next(ok(Ts,Rs), L2-L3).
-
-%% arithmetic_function_expanded(?Term, -ExpandedTerm, ListDifference).
-arithmetic_function_expanded(T, R, LD) :-
-    check(T, R, C), next(C, LD).
-
-%% check(?Term, -ExpandedTerm, -Marker).
-%
-% `Marker` describes what is `Term` in regards to arithmetical function, it is
-% `ok/2` if `Term` is Ok to be a part of arithmetical function and it is `nok/2`
-% if it isn't.
+% Recursively traverse `Term` and assemble a list of replacements that makes up
+% a valid arithmetic relation.
 %
-% NOTE: Order of `check/3` clauses is important for correctness.
-check(T, T, ok([],[])) :- (var(T); number(T)), !.
-check(T, R, ok(Ts,Rs)) :-
-    maplist(loader:elaborate(F/A), [T,R], [Ts,Rs]),
-    arithmetic_functions(A, Fs),
-    member(F, Fs), !.
-check(T, R, nok(T,R)) :- !.
-
-elaborate(Functor/Arity, Term, Args) :-
-    functor(Term, Functor, Arity),
-    Term =.. [Functor|Args].
-
-arithmetic_functions(0, [e,pi,epsilon]).
-arithmetic_functions(1, [+,-,\,sqrt,exp,log,sin,cos,tan,asin,acos,atan,sign,abs,round,ceiling,floor,truncate,float,float_integer_part,float_fractional_part]).
-arithmetic_functions(2, [+,-,/,*,**,^,/\,\/,xor,div,//,rdiv,<<,>>,mod,rem,max,min,gcd,atan2]).
+% NOTE: Order of clauses is important for correctness.
+arithmetic_expansion(func, T, T, L-L) :-
+    (var(T); number(T)), !.
+arithmetic_expansion(list, [], [], L-L) :- !.
+arithmetic_expansion(list, [T0|Ts], [R0|Rs], L1-L3) :-
+    arithmetic_expansion(func, T0, R0, L1-L2),
+    arithmetic_expansion(list, Ts, Rs, L2-L3), !.
+arithmetic_expansion(Set, T, R, LD) :-
+    functor(T, F, A),
+    arithmetic_term(Set, A, Fs),
+    member(F, Fs), !,
+    functor(R, F, A),
+    T =.. [F|Ts],
+    R =.. [F|Rs],
+    arithmetic_expansion(list, Ts, Rs, LD).
+arithmetic_expansion(func, T, R, [T=R|L]-L).
+
+arithmetic_term(func, 0, [e,pi,epsilon]).
+arithmetic_term(func, 1, [+,-,\,sqrt,exp,log,sin,cos,tan,asin,acos,atan,sign,abs,round,ceiling,floor,truncate,float,float_integer_part,float_fractional_part]).
+arithmetic_term(func, 2, [+,-,/,*,**,^,/\,\/,xor,div,//,rdiv,<<,>>,mod,rem,max,min,gcd,atan2]).
+arithmetic_term(rela, 2, [is,>,<,>=,=<,=:=,=\=]).
 
 :- non_counted_backtracking '$print_message_and_fail'/1.
 
@@ -131,7 +112,7 @@
     % Additional rule just to replace invalid arithmetic expression with
     % runtime exception
     nonvar(G),
-    arithmetic_relation_expanded(G, Gx-[]).
+    w(arithmetic_expansion(rela, G, R, Gx-[R])).
 goal_expansion(Goal, Module, ExpandedGoal) :-
     (  atom(Module),
        '$predicate_defined'(Module, goal_expansion, 2),