NuReference.h

//
//  NuReference.h
//  Nu
//
//  Created by Tim Burks on 4/24/16.
//
//

#import <Foundation/Foundation.h>

/*!
 @class NuReference
 @abstract The Nu object wrapper.
 @discussion The NuReference class provides a wrapper for pointers to Objective-C objects.
 NuReference objects are used in the Nu language to capture arguments that are returned by value from Objective-C methods.
 For example, the following Nu method uses a NuReference to capture a returned-by-reference NSError:
 
 <div style="margin-left:2em">
 <code>
 (- (id) save is<br/>
 &nbsp;&nbsp;(set perror ((NuReference alloc) init))<br/>
 &nbsp;&nbsp;(set result ((self managedObjectContext) save:perror))<br/>
 &nbsp;&nbsp;(unless result<br/>
 &nbsp;&nbsp;&nbsp;&nbsp;(NSLog "error: #{((perror value) localizedDescription)}"))<br/>
 &nbsp;&nbsp;result)
 </code>
 </div>
 */
@interface NuReference : NSObject

/*! Get the value of the referenced object. */
- (id) value;
/*! Set the value of the referenced object. */
- (void) setValue:(id) value;
/*! Set the pointer for a reference.  Used by the bridge to create NuReference objects from pointers.  Don't call this from Nu. */
- (void) setPointer:(id *) pointer;
/*! Get a pointer to the referenced object. Used by the bridge to Objective-C to convert NuReference objects to pointers.
 Don't call this from Nu.
 */
- (id *) pointerToReferencedObject;
/*! Retain the referenced object. Used by the bridge to Objective-C to retain values returned by reference. */
- (void) retainReferencedObject;
@end