--- /dev/null
+/**/
+
+:- use_module(library(format)).
+:- use_module(library(dcgs)).
+:- use_module(library(lists)).
+:- use_module(library(debug)).
+:- use_module(library(atts)).
+:- use_module(library(dif)).
+
+% Tests from https://www.complang.tuwien.ac.at/ulrich/iso-prolog/dif
+
+test("dif#1",(
+ call_residual_goals(dif(1,2), Res),
+ Res = []
+)).
+
+test("dif#2",(
+ \+ (dif(1,Y), Y = 1)
+)).
+
+test("dif#3",(
+ call_residual_goals((dif(1,Y), Y=2), Res),
+ Y == 2,
+ Res = []
+)).
+
+test("dif#4",(
+ \+ (dif(X,-Y), X= -Y)
+)).
+
+test("dif#5",(
+ \+ (dif(X,Y), X=Y)
+)).
+
+test("dif#6",(
+ \+ (dif(X,Y), X=Y, X=1)
+)).
+
+test("dif#7",(
+ \+ (dif(-X,-Y), X=Y)
+)).
+
+test("dif#8",(
+ \+ (dif(-X,-Y), X=Y, X=1)
+)).
+
+% I don't understand exactly what is expected for dif#9 and dif#10
+
+test("dif#11",(
+ call_residual_goals((X=Y, dif(X-Y,1-2)), Res),
+ X == Y,
+ Res = []
+)).
+
+test("dif#12",(
+ call_residual_goals((dif(X-Y,1-2), X=Y), Res),
+ X == Y,
+ Res = []
+)).
+
+test("dif#13",(
+ call_residual_goals((X=Y, Y=1, dif(X-Y,1-2)), Res),
+ X == 1,
+ Y == 1,
+ Res = []
+)).
+
+test("dif#14",(
+ call_residual_goals((dif(X-Y,1-2), X=Y, Y=1), Res),
+ X == 1,
+ Y == 1,
+ Res = []
+)).
+
+test("dif#15",(
+ call_residual_goals((dif(X-Y,1-2), X=Y, X=2), Res),
+ X == 2,
+ Y == 2,
+ Res = []
+)).
+
+test("dif#16",(
+ call_residual_goals((dif(A-C,B-D), C-D=z-z, A-B=1-2), Res),
+ A == 1,
+ B == 2,
+ C == z,
+ D == z,
+ Res = []
+)).
+
+test("dif#17",(
+ call_residual_goals((A-B=1-2, C-D=z-z, dif(A-C,B-D)), Res),
+ A == 1,
+ B == 2,
+ C == z,
+ D == z,
+ Res = []
+)).
+
+test("dif#18",(
+ call_residual_goals((dif(A,[C|B]), A=[[]|_], A=[B]), Res),
+ A == [[]],
+ B == [],
+ Res = [dif:dif([[]], [C])]
+)).
+
+test("dif#19",(
+ call_residual_goals((dif([E],[/]), E=1), Res),
+ E == 1,
+ Res = []
+)).
+
+test("dif#20",(
+ call_residual_goals((dif([a],B), B=[_|_], B=[b]), Res),
+ B == [b],
+ Res = []
+)).
+
+test("dif#21",(
+ call_residual_goals((dif([],A), A = [_]), Res),
+ A = [_],
+ Res = []
+)).
+
+test("dif#22",(
+ call_residual_goals((A = [_], dif([],A)), Res),
+ A = [_],
+ Res = []
+)).
+
+test("dif#t1",(
+ set_prolog_flag(occurs_check, false),
+ \+ \+ -X=X
+)).
+
+test("dif#t2",(
+ set_prolog_flag(occurs_check, false),
+ \+ (-X=X, -Y=Y, X\=Y)
+)).
+
+test("dif#t3",(
+ set_prolog_flag(occurs_check, false),
+ call_residual_goals((-X=X, dif(X,1)), Res),
+ X == -X,
+ Res = []
+)).
+
+test("dif#t4",(
+ set_prolog_flag(occurs_check, false),
+ \+ (-X=X, -Y=Y, dif(X,Y))
+)).
+
+test("dif#t5",(
+ set_prolog_flag(occurs_check, false),
+ \+ (dif(X,Y), -X=X, -Y=Y)
+)).
+
+test("dif#t6",(
+ set_prolog_flag(occurs_check, false),
+ \+ (A=[[]|A],dif(A,B),B=[[]|A])
+)).
+
+test("dif#t7",(
+ set_prolog_flag(occurs_check, false),
+ \+ (dif(-X,X),-Y=Y,X=Y)
+)).
+
+test("dif#o1",(
+ set_prolog_flag(occurs_check, true),
+ \+ (-X = X)
+)).
+
+test("dif#o2",(
+ set_prolog_flag(occurs_check, true),
+ call_residual_goals((dif(-X,X)), Res),
+ Res = []
+)).
+
+test("dif#o3",(
+ set_prolog_flag(occurs_check, true),
+ call_residual_goals((dif(-X,Y), X=Y), Res),
+ X == Y,
+ Res = []
+)).
+
+test("dif#12 but with multiple variables in the residuals",(
+ call_residual_goals((dif(X-Y-_, 1-2-3), X = Y), Res),
+ X == Y,
+ Res = []
+)).
+
+main :-
+ findall(test(Name, Goal), test(Name, Goal), Tests),
+ run_tests(Tests, Failed),
+ show_failed(Failed),
+ halt.
+
+portray_failed_([]) --> [].
+portray_failed_([F|Fs]) -->
+ "\"", F, "\"", "\n", portray_failed_(Fs).
+
+portray_failed([]) --> [].
+portray_failed([F|Fs]) -->
+ "\n", "Failed tests:", "\n", portray_failed_([F|Fs]).
+
+show_failed(Failed) :-
+ phrase(portray_failed(Failed), F),
+ format("~s", [F]).
+
+run_tests([], []).
+run_tests([test(Name, Goal)|Tests], Failed) :-
+ format("Running test \"~s\"~n", [Name]),
+ ( call(Goal) ->
+ Failed = Failed1
+ ; format("Failed test \"~s\"~n", [Name]),
+ Failed = [Name|Failed1]
+ ),
+ run_tests(Tests, Failed1).
+
+assert_p(A, B) :-
+ phrase(portray_clause_(A), Portrayed),
+ phrase((B, ".\n"), Portrayed).
+
+call_residual_goals(Goal, ResidualGoals) :-
+ call_residue_vars(Goal, Vars),
+ variables_residual_goals(Vars, ResidualGoals).
+
+variables_residual_goals(Vars, Goals) :-
+ phrase(variables_residual_goals(Vars), Goals).
+
+variables_residual_goals([]) --> [].
+variables_residual_goals([Var|Vars]) -->
+ dif:attribute_goals(Var),
+ variables_residual_goals(Vars).
+