diff options
Diffstat (limited to 'Foundation/GTMNSEnumerator+Filter.m')
| -rw-r--r-- | Foundation/GTMNSEnumerator+Filter.m | 54 |
1 files changed, 26 insertions, 28 deletions
diff --git a/Foundation/GTMNSEnumerator+Filter.m b/Foundation/GTMNSEnumerator+Filter.m index 60c85f3..5ac3a7c 100644 --- a/Foundation/GTMNSEnumerator+Filter.m +++ b/Foundation/GTMNSEnumerator+Filter.m @@ -17,33 +17,35 @@ // #import "GTMNSEnumerator+Filter.h" +#import "GTMDebugSelectorValidation.h" +#import "GTMDefines.h" // a private subclass of NSEnumerator that does all the work. // public interface just returns one of these. // This top level class contains all the additional boilerplate. Specific // behavior is in the subclasses. -@interface GTMEnumerator : NSEnumerator { +@interface GTMEnumeratorPrivateBase : NSEnumerator { @protected NSEnumerator *base_; // STRONG SEL operation_; // either a predicate or a transform depending on context. id other_; // STRONG, may be nil } -- (id)nextObject; +@end + +@interface GTMEnumeratorPrivateBase (SubclassesMustProvide) - (BOOL)filterObject:(id)obj returning:(id *)resultp; @end -@implementation GTMEnumerator + +@implementation GTMEnumeratorPrivateBase - (id)initWithBase:(NSEnumerator *)base sel:(SEL)filter object:(id)optionalOther { self = [super init]; if (self) { - // specializing a nil enumerator returns nil. - if (nil == base) { - [self release]; - return nil; - } - + // someone would have to subclass or directly create an object of this + // class, and this class is private to this impl. + _GTMDevAssert(base, @"can't bas a nil base enumerator"); base_ = [base retain]; operation_ = filter; other_ = [optionalOther retain]; @@ -51,11 +53,9 @@ return self; } -// it is an error to call this initializer. -- (id)init { - [self doesNotRecognizeSelector:_cmd]; - return nil; -} +// we don't provide an init because this base class is private to this +// impl, and no one would be able to create it (if they do, they get whatever +// they happens...). - (void)dealloc { [base_ release]; @@ -72,17 +72,10 @@ } return nil; } - -// subclasses must override -- (BOOL)filterObject:(id)obj returning:(id *)resultp { - [self doesNotRecognizeSelector:_cmd]; - return NO; -} @end // a transformer, for each item in the enumerator, returns a f(item). -@interface GTMEnumeratorTransformer : GTMEnumerator -- (BOOL)filterObject:(id)obj returning:(id *)resultp; +@interface GTMEnumeratorTransformer : GTMEnumeratorPrivateBase @end @implementation GTMEnumeratorTransformer - (BOOL)filterObject:(id)obj returning:(id *)resultp { @@ -93,8 +86,7 @@ // a transformer, for each item in the enumerator, returns a f(item). // a target transformer swaps the target and the argument. -@interface GTMEnumeratorTargetTransformer : GTMEnumerator -- (BOOL)filterObject:(id)obj returning:(id *)resultp; +@interface GTMEnumeratorTargetTransformer : GTMEnumeratorPrivateBase @end @implementation GTMEnumeratorTargetTransformer - (BOOL)filterObject:(id)obj returning:(id *)resultp { @@ -104,8 +96,7 @@ @end // a filter, for each item in the enumerator, if(f(item)) { returns item. } -@interface GTMEnumeratorFilter : GTMEnumerator -- (BOOL)filterObject:(id)obj returning:(id *)resultp; +@interface GTMEnumeratorFilter : GTMEnumeratorPrivateBase @end @implementation GTMEnumeratorFilter // We must take care here, since Intel leaves junk in high bytes of return register @@ -119,8 +110,7 @@ // a target filter, for each item in the enumerator, if(f(item)) { returns item. } // a target transformer swaps the target and the argument. -@interface GTMEnumeratorTargetFilter : GTMEnumerator -- (BOOL)filterObject:(id)obj returning:(id *)resultp; +@interface GTMEnumeratorTargetFilter : GTMEnumeratorPrivateBase @end @implementation GTMEnumeratorTargetFilter // We must take care here, since Intel leaves junk in high bytes of return register @@ -151,6 +141,10 @@ - (NSEnumerator *)gtm_filteredEnumeratorByTarget:(id)target performOnEachSelector:(SEL)selector { + // make sure the object impls this selector taking an object as an arg. + GTMAssertSelectorNilOrImplementedWithArguments(target, selector, + @encode(id), + NULL); return [[[GTMEnumeratorTargetFilter alloc] initWithBase:self sel:selector object:target] autorelease]; @@ -158,6 +152,10 @@ - (NSEnumerator *)gtm_enumeratorByTarget:(id)target performOnEachSelector:(SEL)selector { + // make sure the object impls this selector taking an object as an arg. + GTMAssertSelectorNilOrImplementedWithArguments(target, selector, + @encode(id), + NULL); return [[[GTMEnumeratorTargetTransformer alloc] initWithBase:self sel:selector object:target] autorelease]; |