CODEWITHSUNDEEP
rubycoding-style
23tux
23tux

Reputation: 14726

One-line `if` return statement with two actions

I'm searching for an elegant way to bring the following if statement into one line:

if var1.nil?
  log("some message")
  return
end

I love the right hand if statement where you can say

return if var1.nil?

In this case, I need two actions, but the following doesn't work:

log("some message") and return if var1.nil?

Is there a way to perform two actions (log message and return) with an if at the right side in one line?

Upvotes: 8

Views: 4314

Answers (3)

davidmyersdev
davidmyersdev

Reputation: 1166

Depending on your version of Ruby, there is another way to achieve this that is (in my opinion) a little more readable. The yield_self method that was introduced in Ruby 2.5 has an alias called then as of Ruby 2.6. It is available on all descendents of Object (just about everything, including nil).

log("some message").then { return } if var1.nil?

Since the return keyword will actually exit the current method or lambda context, you can place the return inside the block provided to then. Alternatively, you can just return the result of then since it returns the resolved block value.

return log("some message").then { nil } if var1.nil?

The latter example would also be good for an early exit when the context is another block.

some_vars.map do |var1|
  next log("some message").then { nil } if var1.nil?

  # do something with var1
end

Personally, I think the first example reads a bit better, but it's nice to have a little flexibility when you need it.

Upvotes: 2

Sergio Tulentsev
Sergio Tulentsev

Reputation: 230286

Well, to not depend on boolean evaluations you can always do something like this:

(log('some message'); return) if var.nil?

But I personally find it much less readable than the multiline version

if var1.nil?
  log('some message')
  return
end

One problem with the modifier-if syntax is that you may not even notice it when the line is too long. Observe:

(log('Something really bad happened while you were doing that thing with our app and we are terribly sorry about that. We will tell our engineers to fix this. Have a good day'); return) if var.nil?

Upvotes: 6

sawa
sawa

Reputation: 168081

  1. When you have a method like return, break, etc., you can do (assuming that you are not interested in the return value):

    return log("some message") if var1.nil?

  2. A naive general way is:

    (log("some message"); return) if var1.nil?

  3. But if you don't like the parentheses and semicolon, then, do this: If and does not work, then that means the return value of the first expression is falsy, which means or should work.

    log("some message") or return if var1.nil?

    In general, one or the other between and and or would work, depending on the evaluated value of the first expression.

Upvotes: 11

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