/// <summary>Create a new expression that returns a single result from a source sequence</summary>
public FdbQuerySingleExpression(FdbQuerySequenceExpression <T> sequence, string name, Expression <Func <IAsyncEnumerable <T>, CancellationToken, Task <R> > > lambda)
{
Contract.Requires(sequence != null && lambda != null);
this.Sequence = sequence;
this.Name = name;
this.Handler = lambda;
}
public static string ExplainSequence <T>([NotNull] FdbQuerySequenceExpression <T> expression)
{
if (expression == null)
{
throw new ArgumentNullException("expression");
}
if (expression.Shape != FdbQueryShape.Sequence)
{
throw new InvalidOperationException("Invalid shape (sequence expected)");
}
var expr = expression.CompileSequence();
return(expr.GetDebugView());
}
public static FdbQuerySingleExpression <T, R> Single <T, R>([NotNull] FdbQuerySequenceExpression <T> source, string name, [NotNull] Expression <Func <IFdbAsyncEnumerable <T>, CancellationToken, Task <R> > > lambda)
{
if (source == null)
{
throw new ArgumentNullException("source");
}
if (lambda == null)
{
throw new ArgumentNullException("lambda");
}
if (name == null)
{
name = lambda.Name ?? "Lambda";
}
return(new FdbQuerySingleExpression <T, R>(source, name, lambda));
}
public static FdbQueryFilterExpression <T> Filter <T>([NotNull] FdbQuerySequenceExpression <T> source, [NotNull] Expression <Func <T, bool> > filter)
{
if (source == null)
{
throw new ArgumentNullException("source");
}
if (filter == null)
{
throw new ArgumentNullException("filter");
}
if (source.ElementType != typeof(T))
{
throw new ArgumentException(String.Format("Source sequence has type {0} that is not compatible with filter input type {1}", source.ElementType.Name, typeof(T).Name), "source");
}
return(new FdbQueryFilterExpression <T>(source, filter));
}
public static FdbQueryTransformExpression <T, R> Transform <T, R>([NotNull] FdbQuerySequenceExpression <T> source, [NotNull] Expression <Func <T, R> > transform)
{
if (source == null)
{
throw new ArgumentNullException("source");
}
if (transform == null)
{
throw new ArgumentNullException("transform");
}
if (source.ElementType != typeof(T))
{
throw new ArgumentException(String.Format("Source sequence has type {0} that is not compatible with transform input type {1}", source.ElementType.Name, typeof(T).Name), "source");
}
return(new FdbQueryTransformExpression <T, R>(source, transform));
}
/// <summary>Filter out the elements of e sequence that do not match a predicate</summary>
public static FdbQueryFilterExpression <T> Filter <T>(FdbQuerySequenceExpression <T> source, Expression <Func <T, bool> > filter)
{
if (source == null)
{
throw new ArgumentNullException(nameof(source));
}
if (filter == null)
{
throw new ArgumentNullException(nameof(filter));
}
if (source.ElementType != typeof(T))
{
throw new ArgumentException($"Source sequence has type {source.ElementType.Name} that is not compatible with filter input type {typeof(T).Name}", nameof(source));
}
return(new FdbQueryFilterExpression <T>(source, filter));
}
/// <summary>Transform each elements of a sequence into a new sequence</summary>
public static FdbQueryTransformExpression <T, R> Transform <T, R>(FdbQuerySequenceExpression <T> source, Expression <Func <T, R> > transform)
{
if (source == null)
{
throw new ArgumentNullException(nameof(source));
}
if (transform == null)
{
throw new ArgumentNullException(nameof(transform));
}
if (source.ElementType != typeof(T))
{
throw new ArgumentException($"Source sequence has type {source.ElementType.Name} that is not compatible with transform input type {typeof(T).Name}", nameof(source));
}
return(new FdbQueryTransformExpression <T, R>(source, transform));
}
internal FdbQueryFilterExpression(FdbQuerySequenceExpression <T> source, Expression <Func <T, bool> > filter)
{
Contract.Requires(source != null && filter != null);
this.Source = source;
this.Filter = filter;
}
internal FdbQueryTransformExpression(FdbQuerySequenceExpression <T> source, Expression <Func <T, R> > transform)
{
Contract.Requires(source != null && transform != null);
this.Source = source;
this.Transform = transform;
}
