Java and C# allow either a single statement or a {} block to be used with if, while, and for statements:

if (test) doSomething
if (test) { doSomething }

However for whatever reason they don't consistently do the same for try, catch, and finally which require a {} block. Currently Fan follows the same model, but I propose a change such that Fan consistently allows you to use either a single statement or a {} block.

That will enable more concise code in common cases:

try
  f.readAllLines
catch (Err e)
  e.trace
finally
  f.close

This is something I wondered about for a long time. I think they just did it because C++ does it this way. But I don't know why c++ doesn't allow single statements on try/catch.

If I were choosing I would probably make the {} mandatory for if, while and for. Its error-prone missing them out, and all the tools like checkstyle agree with making them mandatory.

I definitely can see where you are coming from Stephen. Although I think it would be a big turn off for a lot of people to have a curly brace language to go against three decades of C. I personally would find it pretty annoying since I write a lot of one line if statements.

For consistency, I personally prefer Pascal/Eiffel/Ruby style using the "end" keyword more than curly braces. But I stayed away from that to keep things more C/Java/C# like. Although often I think it would make Fan code cleaner.

"If I were choosing I would probably make the {} mandatory for if, while and for. Its error-prone missing them out, and all the tools like checkstyle agree with making them mandatory."

I think it depends very much on the language. In a language like Java you often have to be very wordy to express something, you often need multiple statements. So allways using curly brackets in if-statements feels rather natural (at least to me, and I normaly do so).

But in a language where one-line expressions in "if"s are very common it might be annoying. Just imagine the extrem: a functional language like O'Caml or Haskell where if would require a block ...

I don't have written anything serious in Fan so I realy don't have an opinion.

How about the Perl approach?

if (condition) {
   doSomething();
}

doSomething() if (condition);

Consistency is important. If if doesn't require braces for single statements, then neither should try/catch/finally for single statements.

I like end much better than curly braces, even if the notion is foreign to C's children. It's much cleaner and everyone can agree on how to indent it.

-1 on end for a couple of reasons:

• It adds visual noise (kind of an odd thing to say, come to think of it :-)). I'd rather save English words for things that are meaningful in the code.
• You can end up with Ruby's situation where you're never quite sure if you should use {} or do/end and the language ends up allowing both.

-- Cedric

In a perfect world I'd probably prefer the Eiffel/Ruby end style myself. But for good or bad we chose to stick with curly braces for Fan since it is designed as an alternative to Java and C#.