From: "E. Saynatkari" <none@...>
Date: 2006-03-03T06:21:37+09:00
Subject: Re: Confusion Over Keyword Arguments

Daniel Berger wrote:
> Yukihiro Matsumoto wrote:
>> 
>> 
>>  foo(1, foo:3)     # (a=1, b={:foo=>3}) or (a=1,b=0,c=[{:foo=>3}])?
> 
> Error.  There's no 'foo' parameter.  Passing a literal hash would 
> require {}.
> 
>>  foo(1, 2, 8, c:5) # c={:c=>5}) or c=[8,{:c=>5}] or error?
> 
> Hm.  Either an error or c = [5], depending on whether or not your want 
> to
> declare that, once a positional is used, there's no going back after the 
> fact.
> 
>>  args = [1, {:b=>2, foo=>5}]
>>  foo(*args)        # (a=1,b={:b=>2, foo=>5}) or (a=1,b=2,c=[{:foo=>5}])?
> 
> a = 1, b = {:b=>2, foo=>5}, since you've passed a literal hash.
> 
> Here's the latest test case we had for Sydney.  Note that Sydney assumes 
> that
> all method arguments automatically become keyword arguments.  There's no 
> syntax
> for explicitly declaring that a given method parameter is a valid 
> keyword argument.
> 
> For the kids following along at home, also see
> http://redhanded.hobix.com/inspect/namedParametersArenTTheyAllNamed.html 
> for
> further discussion on the subject.
> 
> Regards,
> 
> Dan

Slightly off-topic but I found this part curious:

> # You can use named parameters, using the name of the parameter 
defined in
> # in the method itself.  It must be the name of the parameter, 
followed by
> # a colon, followed by the value.  Spaces between the parameter 
name, colon
> # and value are not allowed.

Why is this? foo: bar would seem to be more legible with the
added benefit of no confusion with the scope operator :: nor
Symbols.

Your testcases do not seem to cover the scope completely and
Symbols are not included at all. Maybe add something like

  def test_corner_cases()
    # Symbols
    assert_nothing_raised {@foo.bar x:1, y:2, z::symbol}

    # Scopes
    assert_nothing_raised {@foo.bar A::B, y:2, z:3}
    assert_nothing_raised {@foo.bar x:1, y:2, z:::Object}

   assert_nothing_raised{ @foo.bar(z:1, x:2, y:3) }
  end                                      # test_corner_cases

To cover those.

> < snip rest of test cases />


E

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