src/objective-c/RxLibrary/GRXWriteable.h

/*
 *
 * Copyright 2015, Google Inc.
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 *
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 * in the documentation and/or other materials provided with the
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 * this software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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#import <Foundation/Foundation.h>

/**
 * A GRXWriteable is an object to which a sequence of values can be sent. The
 * sequence finishes with an optional error.
 */
@protocol GRXWriteable <NSObject>

/** Push the next value of the sequence to the receiving object. */
- (void)writeValue:(id)value;

/**
 * Signal that the sequence is completed, or that an error ocurred. After this
 * message is sent to the instance, neither it nor writeValue: may be
 * called again.
 */
- (void)writesFinishedWithError:(NSError *)errorOrNil;
@end

typedef void (^GRXValueHandler)(id value);
typedef void (^GRXCompletionHandler)(NSError *errorOrNil);
typedef void (^GRXSingleHandler)(id value, NSError *errorOrNil);
typedef void (^GRXEventHandler)(BOOL done, id value, NSError *error);

/**
 * Utility to create objects that conform to the GRXWriteable protocol, from
 * blocks that handle each of the two methods of the protocol.
 */
@interface GRXWriteable : NSObject<GRXWriteable>

+ (instancetype)writeableWithSingleHandler:(GRXSingleHandler)handler;
+ (instancetype)writeableWithEventHandler:(GRXEventHandler)handler;

- (instancetype)initWithValueHandler:(GRXValueHandler)valueHandler
                   completionHandler:(GRXCompletionHandler)completionHandler
    NS_DESIGNATED_INITIALIZER;
@end