Kit.Core/LibExternal/System.Reactive/Linq/QbservableEx.cs

62 lines
2.1 KiB
C#

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT License.
// See the LICENSE file in the project root for more information.
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;
namespace System.Reactive.Linq
{
/// <summary>
/// Provides a set of static methods for writing queries over observable sequences, allowing translation to a target query language.
/// </summary>
[LocalQueryMethodImplementationType(typeof(ObservableEx))]
#pragma warning disable CA1711 // (Don't use Ex suffix.) This has been a public type for many years, so we can't rename it now.
public static partial class QbservableEx
#pragma warning restore CA1711
{
internal static Expression GetSourceExpression<TSource>(IObservable<TSource> source)
{
if (source is IQbservable<TSource> q)
{
return q.Expression;
}
return Expression.Constant(source, typeof(IObservable<TSource>));
}
internal static Expression GetSourceExpression<TSource>(IEnumerable<TSource> source)
{
if (source is IQueryable<TSource> q)
{
return q.Expression;
}
return Expression.Constant(source, typeof(IEnumerable<TSource>));
}
internal static Expression GetSourceExpression<TSource>(IObservable<TSource>[] sources)
{
return Expression.NewArrayInit(
typeof(IObservable<TSource>),
sources.Select(source => GetSourceExpression(source))
);
}
internal static Expression GetSourceExpression<TSource>(IEnumerable<TSource>[] sources)
{
return Expression.NewArrayInit(
typeof(IEnumerable<TSource>),
sources.Select(source => GetSourceExpression(source))
);
}
internal static MethodInfo InfoOf<R>(Expression<Func<R>> f)
{
return ((MethodCallExpression)f.Body).Method;
}
}
}