Better way to do this?


#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!


#2

Pito S. wrote:

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 &&)


#3

Hi,

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

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


#4

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

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

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

Blessings,
TwP