Merge pull request #13 from kkazuo/fmap

Fmap

NSArray+fmap.m

@@ -0,0 +1,9 @@
+#import "YOLO.ph"
+
+@implementation NSArray (YOLO)
+
+- (NSArray *(^)(id))fmap {
+    return self.map;
+}
+
+@end

NSArray+map.m

@@ -28,7 +28,7 @@ @implementation NSArray (YOLO)
             if (o)
                 mapped[jj++] = o;
         }
-        return [NSArray arrayWithObjects:mapped count:jj];
+        return [[self.class alloc] initWithObjects:mapped count:jj];
     };
 }
 

NSDictionary+fmap.m

@@ -0,0 +1,32 @@
+#import "YOLO.ph"
+
+@implementation NSDictionary (YOLO)
+
+- (NSDictionary *(^)(id))fmap {
+    return ^(id frock) {
+        NSMethodSignature *sig = YOLOMS(frock);
+        id (^block)(id, id) = ^{
+            switch (sig.numberOfArguments){
+                case 2: return ^(id v, id k){ return ((id(^)(id))frock)(v); };
+                case 3: return ^(id v, id k){ return ((id(^)(id, id))frock)(v, k); };
+                case 4: return ^(id v, id k){ return ((id(^)(id, id, id))frock)(v, k, self); };
+                default:
+                    @throw @"Invalid argument count to fmap";
+            }
+        }();
+
+        id keys[self.count];
+        id objs[self.count];
+        int ii = 0;
+        for (id key in self) {
+            id o = block(self[key], key);
+            if (o) {
+                keys[ii]   = key;
+                objs[ii++] = o;
+            }
+        }
+        return [[self.class alloc] initWithObjects:objs forKeys:keys count:ii];
+    };
+}
+
+@end

NSSet+fmap.m

@@ -0,0 +1,18 @@
+#import "YOLO.ph"
+
+@implementation NSSet (YOLO)
+
+- (NSSet *(^)(id (^)(id)))fmap {
+    return ^(id (^block)(id)) {
+        id mapped[self.count];
+        NSUInteger ii = 0;
+        for (id mappable in self) {
+            id o = block(mappable);
+            if (o)
+                mapped[ii++] = o;
+        }
+        return [[self.class alloc] initWithObjects:mapped count:ii];
+    };
+}
+
+@end

YOLO-all.h

@@ -10,6 +10,7 @@
 #define YOLO_FIRST
 #define YOLO_FLATMAP
 #define YOLO_FLATTEN
+#define YOLO_FMAP
 #define YOLO_GET
 #define YOLO_GROUPBY
 #define YOLO_HAS

YOLO.h

@@ -175,6 +175,34 @@
 - (NSArray *(^)(NSArray *(^)(id o)))flatMap;
 #endif
 
+#ifdef YOLO_FMAP
+/**
+ Invokes the given block once for each element of self. Creates a new
+ array containing the values returned by the block.
+
+    id rv = @[@1, @2, @3, @4].fmap(^(NSNumber *n){
+        return @(n.intValue * n.intValue);
+    });
+    // rv => @[@1, @4, @9, @16]
+
+ If the given block returns nil, that element is skipped in the returned
+ array.
+
+ The given block can have up to three parameters, the first is an element
+ in the array, the second that element’s index, and the third the array
+ itself.
+
+ The second parameter can be a primitive (eg. `int`), or an `NSNumber *`:
+
+     @"YOLO".split(@"").fmap(^(NSString *letter, int index){
+         //…
+     });
+
+ @see -map
+*/
+- (NSArray *(^)(id block))fmap;
+#endif
+
 #ifdef YOLO_GROUPBY
 /**
  Groups the collection by result of the given block.
@@ -742,6 +770,13 @@ clear.
 - (NSSet *(^)(void (^)(id o)))each;
 #endif
 
+#ifdef YOLO_FMAP
+/**
+ @see NSArray's -fmap
+*/
+- (NSSet *(^)(id (^)(id obj)))fmap;
+#endif
+
 @end
 
 
@@ -776,6 +811,28 @@ clear.
 - (NSDictionary *(^)(NSDictionary *higherPriorityDictionary))extend;
 #endif
 
+#ifdef YOLO_FMAP
+/**
+ Invokes the given block once for each key, value pair in the receiver.
+ Returns a dictionary containing the values returned by the block.
+
+    id rv = @{@1: @2, @2: @4, @3: @9}.fmap(^(id obj){
+        return @([obj intValue] * 2);
+    });
+    // rv = @{@1: @4, @2: @8, @3: @18}
+
+ If the given block returns nil, that element is skipped in the returned
+ dictionary.
+
+ The given block can have up to three parameters, the first is an element
+ in the dictionary, the second that element’s key, and the third the dictionary
+ itself.
+
+ @see -map
+*/
+- (NSDictionary *(^)(id block))fmap;
+#endif
+
 #ifdef YOLO_GET
 /**
  Returns the value associated with a given key.

YOLOKit.podspec

@@ -13,7 +13,7 @@ Pod::Spec.new do |s|
     ss.preserve_paths = 'YOLO.ph'
   end
 
-  %w{all any array chunk concat dict each extend find first flatMap flatten get
+  %w{all any array chunk concat dict each extend find first flatMap flatten fmap get
     groupBy has indexOf inject join last map max min none partition pick pluck
     pmap pop push reduce reverse rotate sample select shift shuffle skip slice
     snip sort split transpose uniq unshift upTo without
@@ -32,6 +32,8 @@ Pod::Spec.new do |s|
         ss.dependency 'YOLOKit/slice'
       when 'dict'
         ss.dependency 'YOLOKit/transpose'
+      when 'fmap'
+        ss.dependency 'YOLOKit/map'
       when 'join'
         ss.dependency 'YOLOKit/pluck'
       when 'reduce'

tests

@@ -570,6 +570,75 @@ int main() {
     XCTAssertEqualObjects(aa, bb);
 }
 
+- (void)testArrayFmap {
+    NSArray *aaa = @[@"a", @"b", @"c", @"d"];
+    NSArray *aa = aaa.fmap(^(id o, uint ii, id array){
+        return @[o, @(ii), array];
+    });
+    id bb = @[@[@"a", @0, aaa], @[@"b", @1, aaa], @[@"c", @2, aaa], @[@"d", @3, aaa]];
+    XCTAssertEqualObjects(aa, bb);
+    XCTAssertFalse([aa isKindOfClass:[NSMutableArray class]]);
+
+    aa = @[@"a", @"b", @"c", @"d"];
+    bb = aa.fmap(^(id o){
+        return o;
+    });
+    XCTAssertEqualObjects(aa, bb);
+    
+    bb = aa.fmap(^(id o, id i){
+        return [NSString stringWithFormat:@"%@%@", o, i];
+    });
+    aa = @[@"a0", @"b1", @"c2", @"d3"];
+    XCTAssertEqualObjects(aa, bb);
+
+    bb = ((NSArray *)aa.mutableCopy).fmap(^(id o) { return o; });
+    XCTAssertEqualObjects(aa, bb);
+    XCTAssertTrue([bb isKindOfClass:[NSMutableArray class]]);
+}
+
+- (void)testSetFmap {
+    NSSet *aa = [NSSet setWithObjects:@1, @2, @3, nil];
+
+    XCTAssertEqualObjects((aa.fmap(^(id obj) { return obj; })), aa);
+    XCTAssertEqualObjects((aa.fmap(^(id obj) { return (id)nil; })), [NSSet set]);
+    
+    id bb = aa.fmap(^(id obj) {
+        return @([obj intValue] * [obj intValue]);
+    });
+    XCTAssertEqualObjects(bb, ([NSSet setWithObjects:@1, @4, @9, nil]));
+    XCTAssertFalse([bb isKindOfClass:[NSMutableSet class]]);
+    
+    bb = ((NSSet *)aa.mutableCopy).fmap(^(id obj) {
+        return @([obj intValue] * [obj intValue]);
+    });
+    XCTAssertEqualObjects(bb, ([NSSet setWithObjects:@1, @4, @9, nil]));
+    XCTAssertTrue([bb isKindOfClass:[NSMutableSet class]]);
+}
+
+- (void)testDictionaryFmap {
+    XCTAssertEqualObjects(@{}, (@{}.fmap(^(id obj) { return obj; })));
+
+    NSDictionary *aa = @{@1: @2, @2: @4, @3: @9};
+    XCTAssertEqualObjects(aa, (aa.fmap(^(id obj) { return obj; })));
+
+    id bb = aa.fmap(^(id obj){
+        return @([obj intValue] * 2);
+    });
+    XCTAssertEqualObjects(bb, (@{@1: @4, @2: @8, @3: @18}));
+    XCTAssertFalse([bb isKindOfClass:[NSMutableDictionary class]]);
+
+    bb = aa.fmap(^(id obj, id key){
+        return @([obj intValue] * 2 + [key intValue]);
+    });
+    XCTAssertEqualObjects(bb, (@{@1: @5, @2: @10, @3: @21}));
+
+    bb = ((NSDictionary *)aa.mutableCopy).fmap(^(id obj){
+        return @([obj intValue] * 2);
+    });
+    XCTAssertEqualObjects(bb, (@{@1: @4, @2: @8, @3: @18}));
+    XCTAssertTrue([bb isKindOfClass:[NSMutableDictionary class]]);
+}
+
 - (void)testPick {
     NSDictionary *a = @{@1: @2, @2: @3, @3: @4};
     id b = a.pick(@1, @2, @5, nil);