public TObject ExtractInvariants <TObject>(
Expression <Func <TObject, bool> > inputExpression,
out Expression <Func <TObject, bool> > invariantExpression,
TObject cloneSource = default(TObject))
{
var visitor = new InvariantFindingExpressionVisitor <TObject>(cloneSource);
invariantExpression = visitor
.Visit(inputExpression)
as Expression <Func <TObject, bool> >;
if (visitor.MemberValues.Count > 0 || typeof(TObject).IsClass)
{
var invariantObjectBuilder = cloneSource.IsDefaultValue() ?
new Builder <TObject>() :
new Builder <TObject>(cloneSource);
foreach (var memberValue in visitor.MemberValues)
{
var propertyInfo = memberValue.Item1;
var value = memberValue.Item2;
invariantObjectBuilder.Set(propertyInfo.Name, value);
}
return(invariantObjectBuilder.Build());
}
else if (visitor.ThisValue != null)
{
return((TObject)visitor.ThisValue);
}
return(default(TObject));
}
public IReadOnlyDictionary <string, object> ExtractInvariantDictionary <TObject>(
Expression <Func <TObject, bool> > inputExpression,
out Expression <Func <TObject, bool> > invariantExpression)
{
var visitor = new InvariantFindingExpressionVisitor <TObject>();
invariantExpression = visitor
.Visit(inputExpression)
as Expression <Func <TObject, bool> >;
var memberValueCount = visitor.MemberValues.Count;
if (memberValueCount > 0 || typeof(TObject).IsClass)
{
var invariants = new Dictionary <string, object>(memberValueCount);
foreach (var memberValue in visitor.MemberValues)
{
var propertyInfo = memberValue.Item1;
var value = memberValue.Item2;
invariants[propertyInfo.Name] = value;
}
return(invariants);
}
else if (visitor.ThisValue != null)
{
return(new Dictionary <string, object>
{
["this"] = visitor.ThisValue
});
}
return(EmptyReadOnlyDictionary <string, object> .Instance);
}