Initializing instance variables from the parameter list

While looking at NegaPosi, a crazy Ruby implementation of a micro language that only uses unary operators, I discovered a cute way to initialize instance variables. Usually you'd do this:

def initialize
@p = []
@b = []
end

But, how about doing it this way?

def initialize a=@p=[], b=@b=[]
end

Initialize doesn't require the parameters, but it forces @p and @b to be initialized as arrays whenever an instance is created. Cute trick, although the readability suffers.

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This entry was posted on Thursday, May 25th, 2006 at 10:47 pm and is filed under Cool, Ruby Tricks. Both comments and pings are currently closed.