Convert between uint indexes and objects if rqrd.

NSArray+Ruby.m

@@ -1,6 +1,7 @@
 #import "YOLO.h"
 #import <objc/runtime.h>
 extern int YOLOArgCount(id);
+extern NSMethodSignature *YOLOMS(id);
 
 /**
  The blockToUse variable is necessary or: EXC_BAD_ACCESS
@@ -22,7 +23,6 @@
     return [NSArray arrayWithObjects:selected count:ii]
 
 
-
 @implementation NSArray (RubyEnumerable)
 
 - (NSArray *(^)(id))select {
@@ -39,16 +39,27 @@ @implementation NSArray (RubyEnumerable)
 
 - (NSArray *(^)(id))each {
     return ^(id frock) {
-        if (YOLOArgCount(frock) == 3) {
-            void (^block)(id, NSUInteger) = frock;
-            NSUInteger ii = 0;
-            for (id obj in self)
-                block(obj, ii++);
-        } else {
+        NSMethodSignature *sig = YOLOMS(frock);
+        switch (sig.numberOfArguments) {
+        case 2: {
             void (^block)(id) = frock;
             for (id obj in self)
                 block(obj);
+            break;
         }
+        case 3: {
+            void (^block)(id, NSUInteger) = frock;
+
+            if ([sig getArgumentTypeAtIndex:2][0] == '@')
+                block = ^(id o, NSUInteger ii) {
+                    ((void (^)(id, id))frock)(o, @(ii));
+                };
+
+            NSUInteger ii = 0;
+            for (id obj in self)
+                block(obj, ii++);
+            break;
+        }}
         return self;
     };
 }

README.markdown

@@ -58,11 +58,6 @@ id rv = @[@1, @2, @3, @4].map(^(NSNumber *n){
     return @(n.intValue * n.intValue);
 });
 // rv => @[@1, @4, @9, @16]
-
-id rv = @[@1, @2, @3, @4].map(^(NSNumber *n, uint ii){
-    return @(n.intValue * ii);
-});
-// rv => @[@0, @2, @6, @12]
 ```
 
 Notably, if you return nil, we skip that element in the returned array.
@@ -72,9 +67,27 @@ Justification:
 2. We could add NSNull instead, but then we’d be crashy and *YOLOKit is forgiving*
 3. In Objective-C calling a method on nil returns nil. When enumerating an array this is equivalent to just skipping that element. Hence: we skip the element.
 
+```objc
+id rv = @[@1, @2, @3, @4].map(^(NSNumber *n, uint ii){
+    return @(n.intValue * ii);
+});
+// rv => @[@0, @2, @6, @12]
+```
+
+YOLOKit can see how many arguments are in your block.
+
+```objc
+id rv = @[@1, @2, @3, @4].map(^(NSNumber *n, NSNumber *index){
+    return @{index: n};
+});
+// rv => @[@{@0: @1}, @{@1: @2}, @{@2: @3}, @{@3: @4}]
+```
+
+YOLOKit will convert between types for you depending on your block arguments.
+
 ###NSArray.select()
 ```objc
-id rv = @[@1, @2, @3, @4].select(^BOOL(NSNumber *n){
+id rv = @[@1, @2, @3, @4].select(^(NSNumber *n){
     return n.intValue % 2 == 0;
 });
 // rv => @[@2, @4]
@@ -86,7 +99,7 @@ id rv = @[@1, @2, @3, @4].select(^BOOL(NSNumber *n){
 
 ###NSArray.reject()
 ```objc
-id rv = @[@1, @2, @3, @4].reject(^BOOL(NSNumber *n){
+id rv = @[@1, @2, @3, @4].reject(^(NSNumber *n){
     return n.intValue % 2 == 0;
 });
 // rv => @[@1, @3]
@@ -251,7 +264,6 @@ id rv = @[@2, @1, @3, @5, @4].sort;
 
 id rv = @[@"20", @"1", @3, @5, @"4"].sort;
 // rv => @[@"1", @3, @"4", @5, @"20"]   // handles mixed object types
-
 ```
 
 ###NSArray.pluck()
@@ -413,12 +425,12 @@ clear and reads more easily than `isEmpty`. Small wins add up.
 
 ###NSArray.all()
 ```objc
-BOOL rv = @[@1, @2, @3].all(^BOOL(id o){
+BOOL rv = @[@1, @2, @3].all(^(id o){
 	return [o intValue] > 0;
 });
 // rv => YES
 
-BOOL rv = @[@1, @2, @3].all(^BOOL(id o){
+BOOL rv = @[@1, @2, @3].all(^(id o){
 	return [o intValue] < 3;
 });
 // rv => NO

YOLO.m

@@ -39,7 +39,7 @@
     CTBlockDescriptionFlagsHasSignature = (1 << 30)
 };
 
-int YOLOArgCount(id block) {
+NSMethodSignature *YOLOMS(id block) {
     struct CTBlockLiteral *blockRef = (__bridge struct CTBlockLiteral *)block;
     enum CTBlockDescriptionFlags flags = blockRef->flags;
 
@@ -54,7 +54,11 @@ int YOLOArgCount(id block) {
         }
 
         const char *signature = (*(const char **)signatureLocation);
-        return [NSMethodSignature signatureWithObjCTypes:signature].numberOfArguments;
+        return [NSMethodSignature signatureWithObjCTypes:signature];
     }
     return 0;
 }
+
+int YOLOArgCount(id block) {
+    return YOLOMS(block).numberOfArguments;
+}

tests

@@ -103,6 +103,10 @@ int main() {
     @[@1, @2, @3].each(^(id o, int ii){
         XCTAssertEqualObjects(o, @(ii+1));
     });
+
+    @[@0, @1, @2].each(^(id o, id ii){
+        XCTAssertEqualObjects(o, ii);
+    });
 }
 
 - (void)testSelect {