| Код |
%% An example of external database with two B+trees
Domains
db_selector = patients
name = string
diagnosis = string
patient = p(name, diagnosis)
Predicates
ext_open(bt_selector, bt_selector)
ext_close(bt_selector, bt_selector)
enter_patients(bt_selector, bt_selector)
insert_patient(name, decease, bt_selector, bt_selector)
search_patient(bt_selector)
Clauses
ext_open(Pt_sel, Dgs_sel):-
existfile("Patients.dba"), !,
db_open(patients, "Patients.dba", in_file),
bt_open(patients, "Pats_Tree", Pt_sel),
bt_open(patients, "Dgs_Tree", Dcs_sel).
ext_open(Pt_sel, Dcs_sel):-
db_create(patients, "Patients.dba", in_file),
bt_create(patients, "Pats_Tree", Pt_sel, 8, 4),
bt_create(patients, "Dgs_Tree", Dgs_sel, 8, 4).
ext_close(Pt_sel, Dgs_sel):-
bt_close(patients, Pt_sel),
bt_close(patients, Dgs_sel),
db_close(patients).
enter_patients(Pt_sel, Dgs_sel):-
clearwindow, write("Enter a name (Ret to quit): "),
readln(Name), Name <> "", write("Enter a diagnosis:"),
readln(Dec), insert_patient(Name, Dg, Pt_sel, Dgs_sel),
enter_patients(Pt_sel, Dgs_sel).
enter_patients(_,_):- clearwindow.
insert_patient(Name, Dg, Pt_sel, Dgs_sel):-
chain_inserta(patients, pat_chain, patient, p(Name, Dec),
Ref),
key_insert(patients, Pt_sel, Name, Ref),
key_insert(patients, Dgs_sel, Dg, Ref).
search_patient(Pt_sel):-
clearwindow, write("Enter a name to look up(Ret to quit):
"),
readln(Nm), Nm <> "",
Name = "Smith",
key_search(patients, Pt_sel, Name, Ref ),
ref_term(patients, patient, Ref, p(Name, Dec)),
write(Name, Dg), nl,!,
key_search(patients,Pt_sel,Name,Ref1),
ref_term(patients, patient, Ref1, p(Name, Dg)),
write(Name, Dec), nl,fail.
search_patient(_).
Goal
makewindow(1,2,3, "Patients DataBase", 0,0,25,80),
ext_open(Pt_sel, Dcs_sel), enter_patients(Pt_sel, Dgs_sel),
search_patient(Pt_sel), ext_close(Pt_sel, Dgs_sel).
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Почему собственно не компилируется. Не могу понять, помогите. |