Let's say I have a function
def odd_or_even n
  if n%2 == 0
    return :even
  else
    return :odd
  end
end
And I had a simple enumerable array
simple = [1,2,3,4,5]
And I ran it through map, with my function, using a do-end block:
simple.map do
  |n| odd_or_even(n)
end
# => [:odd,:even,:odd,:even,:odd]
How could I do this without, say, defining the function in the first place?  For example,
# does not work
simple.map do |n|
  if n%2 == 0
    return :even
  else
    return :odd
  end
end
# Desired result:
# => [:odd,:even,:odd,:even,:odd]
is not valid ruby, and the compiler gets mad at me for even thinking about it.  But how would I implement an equivalent sort of thing, that works?