dbase.lcl
dbase.lcl
imports employee, empset, stdio;
typedef struct{gender g; job j; int l; int h;} db_q;
typedef enum {db_OK, salERR, genderERR, jobERR,
duplERR, missERR} db_status;
spec immutable type db;
spec db d;
uses dbase, sprint(ioStream, db);
claims UniqueKeys(employee e1, employee e2) db d; {
ensures
(e1 \in d\any /\ e2 \in d\any /\ e1.ssNum = e2.ssNum)
=> (e1 = e2);
}
db_status hire(employee e) db d; {
modifies d;
ensures
(if result = db_OK
then d' = hire(e, d^) else d' = d^)
/\ result =
(if e.gen = gender_ANY then genderERR
else if e.j = job_ANY then jobERR
else if e.salary < 0 then salERR
else if employed(d^, e.ssNum) then duplERR
else db_OK);
}
void uncheckedHire(employee e) db d; {
requires e.gen \neq gender_ANY /\ e.j \neq job_ANY
/\ e.salary >= 0 /\ ~employed(d^, e.ssNum);
modifies d;
ensures d' = hire(e, d^);
}
bool fire(int ssNum) db d; {
modifies d;
ensures result = employed(d^, ssNum)
/\ d' = fire(d^, ssNum);
}
int query(db_q q, empset s) db d; {
modifies s;
ensures s' = s^ \U query(d^, q)
/\ result = size(query(d^, q));
}
bool promote(int ssNum) db d; {
modifies d;
ensures
result = (employed(d^, ssNum)
/\ find(d^, ssNum).j = NONMGR)
/\ (if result then d' = promote(d^, ssNum)
else d' = d^);
}
db_status setSalary(int ssNum, int sal) db d; {
modifies d;
ensures
result =
(if employed(d^, ssNum)
then (if sal < 0 then salERR else db_OK)
else missERR)
/\ (if result = db_OK
then d' = setSal(d^, ssNum, sal)
else d' = d^);
}
void db_print(void) db d; FILE *stdout; {
modifies *stdout^;
ensures
\exists s:ioStream ((*stdout^)' = write((*stdout^)^, s) /\ isSprint(d^, s));
}
void db_initMod(void) db d; {
modifies d;
ensures d' = new;
}
David Evans
University of Virginia, Computer Science
evans@cs.virginia.edu