Why I Dig Objective-C
I apologize if this entry is incoherent or trivial. But I need to build up the habit of blogging.
I recently picked up a copy of Refactoring. I hadn’t heard of that book before I read Steve Yegge’s thoughts on it – indeed, my entire concept of refactoring had previously been limited to Eclipse’s built-in tools. To describe this book as an eye-opener would be an understatement; not only has it taught me many coding strategies (upon reading the entry for Introduce Null Object, I practically screamed “Why didn’t I think of that?”), but it’s also changed many of my ideas about the way I code.
Fowler’s clear, direct writing is one of the strengths of Refactoring; during the book, he introduces the concept of the code smell – a term which I had not heard before, and which perfectly describes a situation with which I have been familiar ever since I started coding – and points out that a sure-fire sign of smelly code is the presence of many comments; if you need to explain a method in excruciating detail, then you’re probably made it too complex.
One of the reasons why I adore Eclipse for Java development is because it shows JavaDoc attributes in its Intellisense methods – I don’t need to navigate through the Java API when I can hit Ctrl+Space and see the arguments the method takes. Without Eclipse, I have to either rely on memory (and in my opinion, life’s too short to memorize the proper sequence of arguments that a proper BufferedReader instance takes) or waste time navigating the API docs.
Objective-C, on the other hand, doesn’t have this – because method signatures can be broken up into multiple pieces. Take a look at these two method signatures – taken straight from the documentation:
- (NSRange)rangeOfString:(NSString *)subString options:(unsigned)mask range:(NSRange)aRange
public NSRange rangeOfString(String s, int i, NSRange nsrange)
When looking at the first method signature, I know that the second object will be an integer that controls the masking – simply by virtue of the fact that, like its parent Smalltalk, its methods recieve messages via keyword messaging. I can also make the assumption – and it is only an assumption – that
- (NSRange)rangeOfString:(NSString *)subString options:(unsigned)mask and
- (NSRange)rangeOfString:(NSString *)subString are valid methods. With the Java API, on the other hand, I have no clue what the second argument does; if I had to know, I’d need to be using Eclipse or XCode, not Emacs or Textmate. Textmate’s Cocoa completions don’t show any HeaderDoc information – but that doesn’t matter: the keywords tell me what the arguments are used for.
It seems to me that Objective-C’s syntax lends itself to clarity by its very nature; Java, on the other hand, depends on other programmers being clear and helpful in their method signatures. And as a short perusal through The Daily WTF reveals, programmers can be very, very unhelpful at times.