From: Kenichi Komiya <kom@...1.accsnet.ne.jp>
Date: 2001-01-06T16:37:21+09:00
Subject: [ruby-talk:8730] Re: Braces and begin/end


Hi, 

From: Kevin Smith <sent@qualitycode.com>

> I've been trying to develop my own Ruby style. 
> Since I came from a C++ world, I realized that 
> the curly braces (with dramatically different 
> meaning) would be confusing to me. So I don't use 
> them. Ever. I always use do/end, formatted like 
> this:

Maybe you better take a closer look at the difference before deciding
that firmly :-)  According to the reference manual for Ruby 1.4, it is
boiled down to:

 - Braces has stronger precedence.
 
 - Braces introduce the nested local scopes.

Let me talk about the former (as later point is well demonstrated in
the manual).  The document says:

  foobar a, b do .. end   # foobar will be called with the block.
  foobar a, b { .. }      # b will be called with the block.

This, in turn, forms a syntax rule that "do .. end" can not be
followed by another method call.  (I am not sure if this is an
inevitable consequence of above precedence rule or just specific to
current implementation, though.)

For example, Ruby allow you to write something like bellow.

  # case-insensitive sort
  ["Foo", "bAr", "zoT"].collect{ |str| 
    [str.downcase, str]
  }.sort.collect{ |pair| 
    pair[1]
  }
  # => ["bAr", "Foo", "zoT"]

But you can not simply replace { .. } with do .. end here (coz, the
call of sort is not allowed after do .. end).

It is, of course, an option that never ever using chain like above.
But I personally feel like being more flexible :)

Minero Aoki has an interesting page discussing things like this at
length (Japanese only).

  http://www1.u-netsurf.ne.jp/~brew/mine/ja/ruby/style.html

Does anyone do the similar thing in English?

Regards,
Kenichi Komiya.