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Diffstat (limited to 'Rx/NET/Source/System.Reactive.Providers/Reactive/Linq/Qbservable.cs')
| -rw-r--r-- | Rx/NET/Source/System.Reactive.Providers/Reactive/Linq/Qbservable.cs | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/Rx/NET/Source/System.Reactive.Providers/Reactive/Linq/Qbservable.cs b/Rx/NET/Source/System.Reactive.Providers/Reactive/Linq/Qbservable.cs new file mode 100644 index 0000000..1429772 --- /dev/null +++ b/Rx/NET/Source/System.Reactive.Providers/Reactive/Linq/Qbservable.cs @@ -0,0 +1,135 @@ +// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information. + +#if !NO_EXPRESSIONS + +#pragma warning disable 1591 + +using System.Collections.Generic; +using System.Linq; +using System.Linq.Expressions; +using System.Reflection; +using System.Reactive.Concurrency; + +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> + public static partial class Qbservable + { + /// <summary> + /// Returns the input typed as an IObservable<TSource>. + /// This operator is used to separate the part of the query that's captured as an expression tree from the part that's executed locally. + /// </summary> + /// <typeparam name="TSource">The type of the elements in the source sequence.</typeparam> + /// <param name="source">An IQbservable<TSource> sequence to convert to an IObservable<TSource> sequence.</param> + /// <returns>The original source object, but typed as an IObservable<TSource>.</returns> + /// <exception cref="ArgumentNullException"><paramref name="source"/> is null.</exception> + public static IObservable<TSource> AsObservable<TSource>(this IQbservable<TSource> source) + { + if (source == null) + throw new ArgumentNullException("source"); + + return source; + } + + /// <summary> + /// Converts an enumerable sequence to an observable sequence. + /// </summary> + /// <typeparam name="TSource">The type of the elements in the source sequence.</typeparam> + /// <param name="source">Enumerable sequence to convert to an observable sequence.</param> + /// <returns>The observable sequence whose elements are pulled from the given enumerable sequence.</returns> + /// <exception cref="ArgumentNullException"><paramref name="source"/> is null.</exception> + /// <remarks>This operator requires the source's <see cref="IQueryProvider"/> object (see <see cref="IQueryable.Provider"/>) to implement <see cref="IQbservableProvider"/>.</remarks> + public static IQbservable<TSource> ToQbservable<TSource>(this IQueryable<TSource> source) + { + if (source == null) + throw new ArgumentNullException("source"); + + return ((IQbservableProvider)source.Provider).CreateQuery<TSource>( + Expression.Call( + null, +#if CRIPPLED_REFLECTION + InfoOf(() => Qbservable.ToQbservable<TSource>(default(IQueryable<TSource>))), +#else + ((MethodInfo)MethodInfo.GetCurrentMethod()).MakeGenericMethod(typeof(TSource)), +#endif + source.Expression + ) + ); + } + + /// <summary> + /// Converts an enumerable sequence to an observable sequence, using the specified scheduler to run the enumeration loop. + /// </summary> + /// <typeparam name="TSource">The type of the elements in the source sequence.</typeparam> + /// <param name="source">Enumerable sequence to convert to an observable sequence.</param> + /// <param name="scheduler">Scheduler to run the enumeration of the input sequence on.</param> + /// <returns>The observable sequence whose elements are pulled from the given enumerable sequence.</returns> + /// <exception cref="ArgumentNullException"><paramref name="source"/> or <paramref name="scheduler"/> is null.</exception> + /// <remarks>This operator requires the source's <see cref="IQueryProvider"/> object (see <see cref="IQueryable.Provider"/>) to implement <see cref="IQbservableProvider"/>.</remarks> + public static IQbservable<TSource> ToQbservable<TSource>(this IQueryable<TSource> source, IScheduler scheduler) + { + if (source == null) + throw new ArgumentNullException("source"); + if (scheduler == null) + throw new ArgumentNullException("scheduler"); + + return ((IQbservableProvider)source.Provider).CreateQuery<TSource>( + Expression.Call( + null, +#if CRIPPLED_REFLECTION + InfoOf(() => Qbservable.ToQbservable<TSource>(default(IQueryable<TSource>))), +#else + ((MethodInfo)MethodInfo.GetCurrentMethod()).MakeGenericMethod(typeof(TSource)), +#endif + source.Expression, + Expression.Constant(scheduler) + ) + ); + } + + internal static Expression GetSourceExpression<TSource>(IObservable<TSource> source) + { + var q = source as IQbservable<TSource>; + if (q != null) + return q.Expression; + + return Expression.Constant(source, typeof(IObservable<TSource>)); + } + + internal static Expression GetSourceExpression<TSource>(IEnumerable<TSource> source) + { + var q = source as IQueryable<TSource>; + if (q != null) + 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; + } + } +} + +#pragma warning restore 1591 + +#endif
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