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/*
*
* Copyright 2015, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#import <Foundation/Foundation.h>
#import "GRXWriter.h"
/**
* Utility to construct GRXWriter instances from values that are immediately available when
* required.
*
* Thread-safety:
*
* An object of this class shouldn't be messaged concurrently by more than one thread. It will start
* messaging the writeable before |startWithWriteable:| returns, in the same thread. That is the
* only place where the writer can be paused or stopped prematurely.
*
* If a paused writer of this class is resumed, it will start messaging the writeable, in the same
* thread, before |setState:| returns. Because the object can't be legally accessed concurrently,
* that's the only place where it can be paused again (or stopped).
*/
@interface GRXImmediateWriter : GRXWriter
/**
* Returns a writer that pulls values from the passed NSEnumerator instance and pushes them to
* its writeable. The NSEnumerator is released when it finishes.
*/
+ (GRXWriter *)writerWithEnumerator:(NSEnumerator *)enumerator;
/**
* Returns a writer that pushes to its writeable the successive values returned by the passed
* block. When the block first returns nil, it is released.
*/
+ (GRXWriter *)writerWithValueSupplier:(id (^)())block;
/**
* Returns a writer that iterates over the values of the passed container and pushes them to
* its writeable. The container is released when the iteration is over.
*
* Note that the usual speed gain of NSFastEnumeration over NSEnumerator results from not having to
* call one method per element. Because GRXWriteable instances accept values one by one, that speed
* gain doesn't happen here.
*/
+ (GRXWriter *)writerWithContainer:(id<NSFastEnumeration>)container;
/**
* Returns a writer that sends the passed value to its writeable and then finishes (releasing the
* value).
*/
+ (GRXWriter *)writerWithValue:(id)value;
/**
* Returns a writer that, as part of its start method, sends the passed error to the writeable
* (then releasing the error).
*/
+ (GRXWriter *)writerWithError:(NSError *)error;
/**
* Returns a writer that, as part of its start method, finishes immediately without sending any
* values to its writeable.
*/
+ (GRXWriter *)emptyWriter;
@end
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