/**
* Calculates the Alloy constraint denoting the relation top test. Takes the shape "forall
* whenvars : when => (forall sourcevars : sourcedomain => (exists targetvars+wherevars :
* targetdomain && where))" Must be run after relation field is created (otherwise recursive calls
* will fail)
*
* @return the Alloy constraint representing the relation
* @throws EchoError
*/
private Expr calculateFact() throws EchoError {
Expr fact = Sig.NONE.no(),
sourceexpr = Sig.NONE.no(),
postexpr = Sig.NONE.no(),
whenexpr = Sig.NONE.no();
Decl[] arraydecl;
ECondition postCondition = relation.getPost();
ECondition targetCondition = targetdomain.getCondition();
try {
if (postCondition != null) {
postCondition.initTranslation(parent_translator, var2varmodel(), modelparam2var, null);
postexpr = (Expr) postCondition.translate();
}
targetCondition.initTranslation(parent_translator, var2varmodel(), modelparam2var, null);
Expr targetexpr = (Expr) targetCondition.translate();
targetexpr = targetexpr.and(postexpr);
if (targetvar2alloydecl.size() == 1)
targetexpr = targetexpr.forSome(targetvar2alloydecl.values().iterator().next());
else if (targetvar2alloydecl.size() > 1) {
arraydecl = targetvar2alloydecl.values().toArray(new Decl[targetvar2alloydecl.size()]);
targetexpr =
targetexpr.forSome(arraydecl[0], Arrays.copyOfRange(arraydecl, 1, arraydecl.length));
}
for (EModelDomain dom : sourcedomains) {
ECondition sourceCondition = dom.getCondition();
sourceCondition.initTranslation(parent_translator, var2varmodel(), modelparam2var, null);
sourceexpr = sourceexpr.and((Expr) sourceCondition.translate());
}
fact = (sourceexpr.implies(targetexpr));
// for (Decl d : sourcevar2alloydecl.values())
// EchoReporter.getInstance().debug("Source var decl: "+d.names+"::"+d.expr);
// for (Decl d : targetvar2alloydecl.values())
// EchoReporter.getInstance().debug("Target var decl: "+d.names+"::"+d.expr);
if (sourcevar2alloydecl.size() == 1) {
fact = fact.forAll(sourcevar2alloydecl.values().iterator().next());
} else if (sourcevar2alloydecl.size() > 1) {
arraydecl = sourcevar2alloydecl.values().toArray(new Decl[sourcevar2alloydecl.size()]);
fact = fact.forAll(arraydecl[0], Arrays.copyOfRange(arraydecl, 1, arraydecl.length));
}
ECondition preCondition = relation.getPre();
if (preCondition != null) {
preCondition.initTranslation(parent_translator, var2varmodel(), modelparam2var, null);
whenexpr = (Expr) preCondition.translate();
fact = (whenexpr.implies(fact));
for (Decl d : whenvar2alloydecl.values()) fact = fact.forAll(d);
}
} catch (Err a) {
throw new ErrorAlloy(
ErrorAlloy.FAIL_CREATE_VAR,
"Failed to create relation constraint variables: " + relation.getName(),
a,
Task.TRANSLATE_TRANSFORMATION);
}
return fact;
}
