public InlineFlattenedTypeVisitor(NewExpression anonymousConstructor, ParameterExpression converted, ParameterExpression initial, AnonymousTypeFlattener flattener)
: base(anonymousConstructor)
{
_initial = initial;
_converted = converted;
_flattener = flattener;
}
protected internal override QueryOperator VisitSelect(SelectOperator op)
{
var src = VisitAndConvert <MonadMember>(op.Source);
var selector = Visit(op.Selector);
if (TryCast <SelectOperator>(src, OperatorType.Select, out SelectOperator select1) &&
TryExtractNullaryLambdaBody <LambdaExpression>(select1.Selector, ExpressionType.Lambda, out LambdaExpression selector1) &&
TryGetNewAnonymousType(selector1.Body, out NewExpression anonCtor1) &&
TryExtractNullaryLambdaBody <LambdaExpression>(selector, ExpressionType.Lambda, out LambdaExpression selector2))
{
if (TryGetNewAnonymousType(selector2.Body, out NewExpression anonCtor2))
{
if (anonCtor2.Members.Count > 0 && anonCtor2.Arguments[0] == selector2.Parameters[0])
{
var newArgs = new Expression[anonCtor2.Members.Count];
newArgs[0] = anonCtor1;
for (var i = 1; i < newArgs.Length; i++)
{
var visitor = new ValidateMemberAccessesAndInlineVisitor(anonCtor1, selector1.Parameters[0], selector2.Parameters[0]);
newArgs[i] = visitor.Visit(anonCtor2.Arguments[i]);
if (!visitor.Valid)
{
return(UpdateSelect(op, src, selector));
}
}
var updated = anonCtor2.Update(newArgs);
var newBody =
DefaultQueryExpressionFactory.Instance.LambdaAbstraction(
Expression.Lambda(Expression.Lambda(updated, selector1.Parameters[0])),
Array.Empty <QueryTree>()
);
return
(op.QueryExpressionFactory.Select(
op.ElementType,
select1.InputElementType,
select1.Source,
newBody
));
}
}
else
{
var flatteningValidationVisitor = new ValidateMemberAccessVisitor(anonCtor1, selector2.Parameters[0]);
flatteningValidationVisitor.Visit(selector2.Body);
if (flatteningValidationVisitor.Valid)
{
var flattener = new AnonymousTypeFlattener(anonCtor1);
if (flattener.TryConstruct(out NewExpression c))
{
var t = c.Type;
var newParam = Expression.Parameter(t);
var flatteningVisitor = new InlineFlattenedTypeVisitor(anonCtor1, newParam, selector2.Parameters[0], flattener);
var f = flatteningVisitor.Visit(selector2.Body);
var child =
select1.QueryExpressionFactory.Select(
t,
select1.InputElementType,
select1.Source,
DefaultQueryExpressionFactory.Instance.LambdaAbstraction(
Expression.Lambda(Expression.Lambda(c, selector1.Parameters[0])),
Array.Empty <QueryTree>()
)
);
return
(op.QueryExpressionFactory.Select(
op.ElementType,
t,
child,
DefaultQueryExpressionFactory.Instance.LambdaAbstraction(
Expression.Lambda(Expression.Lambda(f, newParam)),
Array.Empty <QueryTree>()
)
));
}
}
}
}
return(UpdateSelect(op, src, selector));
}
