Question

I’m going through a phase of trying to avoid temporary variables and over-use of conditional where I can use a more fluid style of coding. I’ve taken a great liking to using #tap in places where I want to get the value I need to return, but do something with it before I return it.

def fluid_method
  something_complicated(a, b, c).tap do |obj|
    obj.update(:x => y)
  end
end

Vs. the procedural:

def non_fluid_method
  obj = something_complicated(a, b, c)
  obj.update(:x => y)
  obj # <= I don't like this, if it's avoidable
end

Obviously the above examples are simple, but this is a pretty common coding style in the ruby community nonetheless. I’ll sometimes use #inject to pass an object through a series of filters too:

things.inject(whatever) do |obj, thing|
  thing.filter(obj)
end

Vs. the procedural:

obj = whatever
things.each do |thing|
  obj = thing.filter(obj)
end
obj

Now I’m facing repeated use of a condition like the following, and looking for a more fluid approach to handling it:

def not_nice_method
  obj = something_complex(a, b, c)
  if a_predicate_check?
    obj.one_more_method_call
  else
    obj
  end
end

The (slightly) cleaner solution is to avoid the temporary variable at the cost of duplication:

def not_nice_method
  if a_predicate_check?
    something_complex(a, b, c).one_more_method_call
  else
    something_complex(a, b, c)
  end
end

I can’t help but feeling the desire to use something almost like #tap here though.

What other patterns might I follow here. I realise this is all just nonsensical sugar to some people and that I should just move onto more interesting problems, but I’m trying to learn to write in a more functional style, so I’m just curious what long-term rubyists have determined to be good ways to tackle situations like this. These examples are hugely simplified.

Answer 1

Define Object#as:

class Object
  def as
    yield self
  end
end

And now you can write:

def not_sure_this_is_nice_enough_method1
  something_complex(a, b, c).as do |obj| 
    a_predicate_check? ? obj.one_more_method_call : obj
  end
end