public override IExpr /*!*/ ToPredicate(IVariable /*!*/ var, Element /*!*/ element)
{
//Contract.Requires(element != null);
//Contract.Requires(var != null);
Contract.Ensures(Contract.Result <IExpr>() != null);
Elt e = (Elt)element;
switch (e.what)
{
case What.Bottom:
return(propFactory.False);
case What.Exact:
return(factory.IsExactlyA(var, cce.NonNull(e.ty)));
case What.Bounds:
if (e.ty == null && e.manyBounds == null)
{
return(propFactory.True);
}
else if (e.ty != null)
{
return(factory.IsA(var, e.ty));
}
else
{
IExpr /*!*/ p = factory.IsA(var, (IExpr /*!*/)cce.NonNull(e.manyBounds)[0]);
for (int i = 1; i < e.manyBounds.Length; i++)
{
p = propFactory.And(p, factory.IsA(var, (IExpr /*!*/)cce.NonNull(e.manyBounds[i])));
}
return(p);
}
default: {
Contract.Assert(false);
throw new cce.UnreachableException();
}
throw new System.Exception();
}
}
public override IExpr /*!*/ ToPredicate(Element /*!*/ element)
{
//Contract.Requires(element != null);
Contract.Ensures(Contract.Result <IExpr>() != null);
if (IsTop(element))
{
return(propExprFactory.True);
}
if (IsBottom(element))
{
return(propExprFactory.False);
}
Elt e = (Elt)element;
IExpr truth = propExprFactory.True;
IExpr result = truth;
foreach (IVariable /*!*/ variable in e.SortedVariables(variableComparer))
{
Contract.Assert(variable != null);
Element value = (Element)e[variable];
if (value == null || this.microLattice.IsTop(value))
{
continue;
} // Skip variables about which we know nothing.
if (this.microLattice.IsBottom(value))
{
return(propExprFactory.False);
}
IExpr conjunct = this.microLattice.ToPredicate(variable, value);
result = (result == truth) ? (IExpr)conjunct : (IExpr)propExprFactory.And(result, conjunct);
}
return(result);
}
//
// Utility Methods
//
public static IExpr/*!*/ SimplifiedAnd(IPropExprFactory/*!*/ factory, IExpr/*!*/ e0, IExpr/*!*/ e1) {
Contract.Requires(e1 != null);
Contract.Requires(e0 != null);
Contract.Requires(factory != null);
Contract.Ensures(Contract.Result<IExpr>() != null);
IFunApp fun0 = e0 as IFunApp;
if (fun0 != null) {
if (fun0.FunctionSymbol.Equals(Prop.True)) {
return e1;
} else if (fun0.FunctionSymbol.Equals(Prop.False)) {
return e0;
}
}
IFunApp fun1 = e1 as IFunApp;
if (fun1 != null) {
if (fun1.FunctionSymbol.Equals(Prop.True)) {
return e0;
} else if (fun1.FunctionSymbol.Equals(Prop.False)) {
return e1;
}
}
return factory.And(e0, e1);
}