From: David Vallner <david@...>
Date: 2006-12-08T17:22:00+09:00
Subject: Re: Default values for method arguments

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Ken Bloom wrote:
> Try this-- it's more concise, and you probably won't feel the need
> for more syntactic magic after that.
>=20
> def test(args)
>   args[:a] ||=3D 'defaultA'
>   args[:b] ||=3D 'defaultB'
>   args[:c] ||=3D 'defaultC'
>   puts args.indexes(:a, :b, :c)
> end
>=20

I find:

def test(args)
  realargs =3D {:a =3D> 'defaultA',
   :b =3D> 'defaultB',
   :c =3D> 'defaultC'}.update(args)

  puts args.indexes(:a, :b, :c)
end

more readable. Preferrably extracting the default values into constants
before the method definition and (deep?)cloning the hash.

Also, your code clobbers the hash put into args by putting in values.
This might not cause bugs most of the case, but might in case someone
passes in an actual hash, so I'd just stay on the safe side.

David Vallner


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