R – Parsing namespaced XML using libxml-ruby

Ruby uses the case expression instead.

case x
when 1..5
  "It's between 1 and 5"
when 6
  "It's 6"
when "foo", "bar"
  "It's either foo or bar"
when String
  "You passed a string"
else
  "You gave me #{x} -- I have no idea what to do with that."
end

Ruby compares the object in the when clause with the object in the case clause using the === operator. For example, 1..5 === x, and not x === 1..5.

This allows for sophisticated when clauses as seen above. Ranges, classes and all sorts of things can be tested for rather than just equality.

Unlike switch statements in many other languages, Ruby’s case does not have fall-through, so there is no need to end each when with a break. You can also specify multiple matches in a single when clause like when "foo", "bar".

Since they both come from the same source they are both just as likely to be reliable. As for speed it would be impossible to tell and is likely to fluctuate due to environmental variables that cannot be known from your question alone.

As with all things - code the solution that is the clearest, easiest to read, and easiest to maintain. Then, if performance becomes and issue, profile your application to determine if this data feed is the source of your performance problem. Then, if you have verified that it is in fact the source of the performance problem then begin investigating ways to improve the performance.

All things being equal, I would speculate that these two data feeds would be retrieved and read by your application at similar speeds.