From: Eric Mahurin <eric_mahurin@...>
Date: 2005-05-12T21:51:03+09:00
Subject: Re: simple object loops and what they return

> > > That sure looks ugly.  I don't see any advantage of this
> over:
> > >
> > > my_array.each do |item|
> > >    puts "item"
> > > end
> > > if my_array.empty?
> > >    puts "(no items found)"
> > > end
> > 
> > *shrug* I personally prefer what I posted over this. (I
> tend to use {
> > and } for blocks instead of begin/end in my own code
> because IMHO it
> > visually groups it better, but I used begin/end here since
> that seems
> > to be the emerging multi-line choice of the community.)
> > [snip]
> 
> I just wanted to throw in that I'm in the camp of people who
> use begin
> end when the side effect is important and braces when the
> return value
> is important. This conveys  more meaning on a causual glance.
> I.e.
> 
> print "100!"
> puts (1..100).inject(1) { | r, i  | 
>   r*i 
> }
> 
> (1..100).inject(1) do | r, i | 
>   puts "#{i}! = #{r = r*i}" 
> end

inject clearly does what is supposed to.  I'm not referring to
it.  I'm referring to the following loops that are similar to
plain while/until/loop loops:

enum.each {|o| ...} -> enum or break value
enum.each_with_index {|o,i| ...} -> enum  or break value
for o in enum; ... end -> enum  or break value
int.times {|i| ...} -> int or break value
int.downto(stop) {|i| ...} -> int or break value
int.upto(stop) {|i| ...} -> int or break value
int.step(stop,step) {|i| ...} -> int or break value

Compare this to the traditional loops:

loop { ... } -> nil or break value
while ...; ... end -> nil or break value
until ...; ... end -> nil or break value
begin ... end while ... -> nil or break value
begin ... end until ... -> nil or break value

I guess many may not know that break can take a value as an
argument and make the broken loop return that.  I find this
behavior quite useful except for those loops that return
something other than nil in the no-break case (the object loops
above).

What about the Integer loops above?  Anybody using what those
return now - the original int?  Maybe I could propose just
those loops.



		
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