Comments on: Rubyize this

By: Gerry

Gerry — Mon, 25 Jun 2007 04:41:30 +0000

Here is an alternative to get the idea rolling.

def manage_ducks(ducks)
  if ducks.nil? || !ducks.won_stanley_cup?
    ducks = fetch_some_champions
  end
  ducks.beat_random_opponent
end

By: Gerry

Gerry — Mon, 25 Jun 2007 04:42:40 +0000

it doesn’t appear that wrapping in tags works.

By: Alpha Chen

Alpha Chen — Mon, 25 Jun 2007 05:02:29 +0000

ducks = fetch_some_champions unless ducks and ducks.won_stanley_cup?
ducks.beat_random_opponent

By: Jbosss

Jbosss — Mon, 25 Jun 2007 11:13:07 +0000

The code is ugly indeed. I agree with Aplha Chen’s suggestion, its the same I have came up with. Pretty and still nice and readable.

By: Nando Vieira

Nando Vieira — Mon, 25 Jun 2007 12:15:21 +0000

Here it is:

def manage_ducks(ducks)
  ducks = ducks.fetch_some_champions unless ducks.nil? || ducks.won_stanley_cup?
  ducks.beat_random_opponent
end

By: Casey Winans

Casey Winans — Mon, 25 Jun 2007 12:52:11 +0000

def manage_ducks(ducks)
  ducks = fetch_some_champions if ducks.nil? || !ducks.won_stanley_cup?
  ducks.beat_random_opponent
end

By: Silvio Fonseca

Silvio Fonseca — Mon, 25 Jun 2007 13:06:40 +0000

Nando and Alpha Chen solutions were exactly what I had in mind. IMHO, Nando's solutions is a bit better, using the "nil?" method, which is easier to understand. Just a minor correction on the logic:

def manage_ducks(ducks)
  ducks = ducks.fetch_some_champions if ducks.nil? || !ducks.won_stanley_cup?
  ducks.beat_random_opponent
end

By: RSL

RSL — Mon, 25 Jun 2007 15:18:08 +0000

One thing I noticed no one was doing is taking advantage of Ruby returning an object from assignment. The whole ducks.beat_random_opponent thing can do without the ducks.

# Verbose
def manage_ducks(ducks)
  unless ducks and ducks.won_stanley_cup?
    fetch_some_champions
  else
    ducks
  end.beat_random_opponent
end

# Superterse, if Perl-y
def manage_ducks(ducks)
  ((ducks && ducks.won_stanley_cup?) ? ducks : fetch_some_champions).beat_random_opponent
end

By: RSL

RSL — Mon, 25 Jun 2007 15:20:02 +0000

Also, you don’t have to ask “if ducks.nil?” when “if ducks” works just fine and is perfectly idiomatic Ruby.

By: Frank

Frank — Mon, 25 Jun 2007 22:33:09 +0000

Thanks everyone for commenting in this first edition of Rubyize this (seeing it was quite popular there will be some more).

My favorite solution is without a doubt the one by Nando (once you remove the logic mistake like Silvio has pointed out) and Casey. In this situation I prefer the if over unless because it feels more natural. (unless ducks and ducks.won_stanley_cup? can be a bit confusing when you read it).

I’d also like to talk about RSL suggestions which I find very interesting (the second one is a bit cryptic… but still pretty nice). Although the first solution looks awkward at first, I find it extremely readable and clean. I’ll try to include some of this stuff in my applications in the future.

RSL, however I don’t understand your last comment. “if ducks.nil?” is definitely not the same as “if ducks”. I guess you wanted to say “unless ducks”.

By: Nando Vieira

Nando Vieira — Mon, 25 Jun 2007 23:14:08 +0000

Sorry… my bad!
I posted it without reviewing just to be fast.. huahahuahuau.

By: RSL

RSL — Tue, 26 Jun 2007 03:24:25 +0000

Woops. You’re right. I did have that backwards. I guess I shouldn’t post comments [especially not ones containing _code_] before I’ve finished my morning coffee.

By: Matt Jones

Matt Jones — Thu, 28 Jun 2007 02:10:59 +0000

A little late, but this is an interesting approach:

def manage_ducks(ducks)
throw(nil) unless ducks.won_stanley_cup? rescue ducks = fetch_some_champions
ducks.beat_random_opponent
end

A little weird, but it works. If ducks is nil, the unless clause will throw an exception; if
won_stanley_cup? is false, it throws a nil exception.