Better way to do this?

ruby-talk
1

Hi,

I seem to be repeating myself in the following little bit:

if (!@options[:namespace].nil?)
    namespace_options = @options[:namespace]
    root.add_namespace(namespace_options[:namespace],
namespace_options[:value])
end

Can someone show me a way to not repeat options[:namespace] ?

Simpler example of the exact same:

if (!hash[:value].nil?)
    h = hash[:value]
    puts h[:left], h[:right]
end

Thanks for any tips for writing more idiomatic ruby!

···

--
Posted via http://www.ruby-forum.com/.

2

Pito Salas wrote:

Hi,

I seem to be repeating myself in the following little bit:

if (!@options[:namespace].nil?)
    namespace_options = @options[:namespace]
    root.add_namespace(namespace_options[:namespace],
namespace_options[:value])
end

Can someone show me a way to not repeat options[:namespace] ?

Simpler example of the exact same:

if (!hash[:value].nil?)
    h = hash[:value]
    puts h[:left], h[:right]
end

hash = {
   :value => {:left => 1, :right => 2}
}

# original:
if (!hash[:value].nil?)
     h = hash[:value]
     puts h[:left], h[:right]
end

# looking up :value only once
h = hash[:value]
if h ## assuming you don't use false as a value in the hash
   puts h[:left], h[:right]
end

# living a little dangerously (assignment in conditional):
if (h = hash[:value])
   puts h[:left], h[:right]
end

# more compactly, if you care:
h = hash[:value] and puts h[:left], h[:right]

# the last one depends on 'and' having low precedence (unlike &&)

···

--
       vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407

3

Hi,

if (!hash[:value].nil?)
    h = hash[:value]
    puts h[:left], h[:right]
end

Untested:

  if (!(h = hash[:value]).nil?)
    puts h[:left], h[:right]
  end

or

  h = hash[:value]
  unless h.nil? then
    puts h[:left], h[:right]
  end

or

  h = hash[:value]
  h.nil? or puts h[:left], h[:right]

Hope you enjoyed the trip.

Bertram

···

Am Freitag, 13. Feb 2009, 07:24:59 +0900 schrieb Pito Salas:

--
Bertram Scharpf
Stuttgart, Deutschland/Germany
http://www.bertram-scharpf.de

4

if (h = hash[:value])
   puts h[:left], h[:right]
end

Blessings,
TwP

···

On Feb 12, 2009, at 3:24 PM, Pito Salas wrote:

Hi,

I seem to be repeating myself in the following little bit:

if (!@options[:namespace].nil?)
   namespace_options = @options[:namespace]
   root.add_namespace(namespace_options[:namespace],
namespace_options[:value])
end

Can someone show me a way to not repeat options[:namespace] ?

Simpler example of the exact same:

if (!hash[:value].nil?)
   h = hash[:value]
   puts h[:left], h[:right]
end