From: James Gray <james@...>
Date: 2009-04-27T07:48:10+09:00
Subject: Block Style

I hate to be the guy to start another { … } vs. do … end thread, but I  
have some questions I would love to hear opinions on.

I use to just use the rule of { … } for one-liners and do … end for  
the longer stuff.  However, I've recently switched to trying out { … }  
for the times when I care about the return value and do … end for the  
times the block is for side effects.  For the most part, I do like the  
new strategy, but sometimes I have trouble deciding which to use.

Let me give two examples that have made me stop and think.

First, tap() is Ruby 1.9 is a little tricky.  I do care about the  
return value, but not the return value of the block, so which strategy  
should I use?  It seems like do … end is more correct, but that seems  
a lot uglier in practice:

   arr.sort.tap do |sorted|
     p sorted
   end.whatever…

Another example is with a transaction() method for a database.  When  
using such a tool, I often end up with calls where I care about both  
the side effects (transactional behavior) and the return value:

   db.transaction {
     db[:count] += 1
     db[:count]
   }

Any thoughts on how edge cases like this mesh with the block strategy?

James Edward Gray II