[#20675] RCR: non-bang equivalent to []= — Tobias Reif <tobiasreif@...>

Hi,

49 messages 2001/09/01
[#20774] Re: RCR: non-bang equivalent to []= — Tobias Reif <tobiasreif@...> 2001/09/03

I wrote:

[#20778] Re: RCR: non-bang equivalent to []= — Kevin Smith <kevinbsmith@...> 2001/09/03

--- Tobias Reif <tobiasreif@pinkjuice.com> wrote:

[#20715] oreilly buch von matz - website online — markus jais <info@...>

hi

43 messages 2001/09/02
[#20717] Re: OReilly Ruby book has snail on cover — ptkwt@...1.aracnet.com (Phil Tomson) 2001/09/02

Actually, thanks for posting it here. I was trying to search OReilly's

[#20922] Re: OReilly Ruby book has snail on cover — Paul Brannan <pbrannan@...> 2001/09/05

On Mon, 3 Sep 2001, Phil Tomson wrote:

[#20768] Minor cgi.rb question — "Hal E. Fulton" <hal9000@...>

I don't have much experience with

25 messages 2001/09/03

[#20770] Calling member methods from C++ — jglueck@... (Bernhard Glk)

Some quetsions have been solved for me, but my message system does not

12 messages 2001/09/03

[#20976] destructor — Frank Sonnemans <ruby@...>

Does Ruby have a destructor as in C++?

25 messages 2001/09/07

[#21218] Ruby objects <-> XML: anyone working on this? — senderista@... (Tobin Baker)

Are there any Ruby analogs of these two Python modules (xml_pickle,

13 messages 2001/09/15

[#21296] nested require files need path internally — Bob Gustafson <bobgus@...>

Version: 1.64

29 messages 2001/09/18
[#21298] Re: nested require files need path internally — David Alan Black <dblack@...> 2001/09/18

Hello --

[#21302] Re: nested require files need path internally — Bob Gustafson <bobgus@...> 2001/09/18

On Tue, 18 Sep 2001, David Alan Black wrote:

[#21303] Re: nested require files need path internally — matz@... (Yukihiro Matsumoto) 2001/09/18

Hi,

[#21306] Re: nested require files need path internally — Lars Christensen <larsch@...> 2001/09/18

On Tue, 18 Sep 2001, Yukihiro Matsumoto wrote:

[#21307] Re: nested require files need path internally — matz@... (Yukihiro Matsumoto) 2001/09/18

Hi,

[#21331] Re: nested require files need path internally — Paul Brannan <pbrannan@...> 2001/09/18

> The big difference is C++ search done in compile time, Ruby search

[#21340] Re: nested require files need path internally — matz@... (Yukihiro Matsumoto) 2001/09/18

Hi,

[#21353] Re: nested require files need path internally — Paul Brannan <pbrannan@...> 2001/09/18

On Wed, 19 Sep 2001, Yukihiro Matsumoto wrote:

[#21366] Re: nested require files need path internally — matz@... (Yukihiro Matsumoto) 2001/09/19

Hi,

[#21368] Re: nested require files need path internally — "Julian Fitzell" <julian-ml@...4.com> 2001/09/19

On 19/09/2001 at 10:12 AM matz@ruby-lang.org wrote:

[#21376] Re: nested require files need path internally — matz@... (Yukihiro Matsumoto) 2001/09/19

Hi,

[#21406] Re: nested require files need path internally — Paul Brannan <pbrannan@...> 2001/09/19

On Wed, 19 Sep 2001, Yukihiro Matsumoto wrote:

[#21315] Suggestions for new CGI lib — anders@... (Anders Johannsen)

From the comp.lang.ruby thread "Minor cgi.rb question" (2001-09-03), I

21 messages 2001/09/18

[#21413] Ruby/objects book in style of The Little Lisper — Brian Marick <marick@...>

I fell in love with Lisp in the early 80's. Back then, I read a book called

36 messages 2001/09/19
[#21420] Re: Ruby/objects book in style of The Little Lisper — Christopher Sawtell <csawtell@...> 2001/09/20

On 20 Sep 2001 06:19:44 +0900, Brian Marick wrote:

[#21479] Re: Ruby/objects book in style of The Little Lisper — Kevin Smith <kevinbsmith@...> 2001/09/21

--- Christopher Sawtell <csawtell@paradise.net.nz> wrote:

[#21491] SV: Re: Ruby/objects book in style of The Little Lisper — "Mikkel Damsgaard" <mikkel_damsgaard@...> 2001/09/21

[#21494] Re: SV: Re: Ruby/objects book in style of The Little Lisper — Kevin Smith <kevinbsmith@...> 2001/09/21

--- Mikkel Damsgaard <mikkel_damsgaard@mailme.dk> wrote:

[#21510] Re: SV: Re: Ruby/objects book in style of The Little Lisper — Todd Gillespie <toddg@...> 2001/09/22

On Sat, 22 Sep 2001, Kevin Smith wrote:

[#21514] Re: SV: Re: Ruby/objects book in style of The Little Lisper — Kevin Smith <kevinbsmith@...> 2001/09/22

--- Todd Gillespie <toddg@mail.ma.utexas.edu> wrote:

[#21535] irb — Fabio <fabio.spelta@...>

Hello. :) I'm new here, and I have not found an archive of the previous

15 messages 2001/09/22

[#21616] opening a named pipe? — "Avdi B. Grimm" <avdi@...>

I'm having trouble reading from a named pipe in linux. basicly, I'm

12 messages 2001/09/24

[#21685] manipulating "immutable" objects such as Fixnum from within callbacks & al... — Guillaume Cottenceau <gc@...>

Hello,

15 messages 2001/09/25

[#21798] Ruby internal (guide to the source) — "Benoit Cerrina" <benoit.cerrina@...>

Hi,

22 messages 2001/09/28

[ruby-talk:21703] Re: strange behaviors

From: David Alan Black <dblack@...>
Date: 2001-09-26 01:26:49 UTC
List: ruby-talk #21703
Hello --

On Wed, 26 Sep 2001, Avdi B. Grimm wrote:

> Hello,
>
> In the process of a frighteningly productive spate of Ruby coding
> today, I ran across some seeming quirks in the language.  I'm curious
> whether these are bugs, features, known eccentricities, or what, so I
> thought I'd post them and see if anyone else is familiar with the
> behaviors I encountered.
>
> Quirk #1: Inconsistent name resolution in instance methods

This is mentioned in the pickaxe (page 78).  (Albeit with a typo, in
the first printing :-)  It's not really inconsistent: it's part of the
whole process of Ruby deciding what's a method and what's a variable,
which involves looking for assignments and inferring variableness from
them (so that "thing = 10" means that "thing" is a local variable).

That's not a very full explanation, but tiredness is descending and I
want to say more about Quirk #2 :-)

> Quirk #2: Constants aren't dynamically resolved
[...]
> class Parent
>   CONSTANT = "foo"
>
>   def Parent.implicit
>     CONSTANT          # always resolves to Parent::CONSTANT
>   end
>
>   def Parent.explicit
>     self::CONSTANT    # resolves dynamically
>   end
> end
>
> class Child < Parent
>   CONSTANT = "bar"
> end
>
> puts Child.implicit # prints "foo"
> puts Child.explicit # prints "bar"
>
>
> The implicit internal reference to CONSTANT always yields the value of
> CONSTANT for the class in which the current method was defined.  To
> get the value of CONSTANT for the current class, I must explicitly ask
> for it with self::CONSTANT.

The thing is, constants aren't supposed to be dynamic -- they're
supposed to be constant :-)

So where you've written:

  CONSTANT = "foo"
  def Parent.implicit
    CONSTANT
  end

the effect is as if you'd simply written:

  def Parent.implicit
    "foo"
  end

So when you then call Child.implicit, and Ruby looks for the method
and finds it in Parent, there's nothing to resolve.  The method
behaves a certain way, based on its definition.

Here's a further example which might clarify this:

  class Parent   # as above
    CONSTANT = "foo"
    def Parent.implicit; CONSTANT; end
    def Parent.explicit; self::CONSTANT; end
  end

  class Child < Parent
    CONSTANT = "bar"

    puts Parent.implicit
    puts self.implicit

    def Parent.implicit; CONSTANT; end

    puts Parent.implicit
    puts self.implicit
  end

  =>
     foo
     foo
     bar
     bar


David

-- 
David Alan Black
home: dblack@candle.superlink.net
work: blackdav@shu.edu
Web:  http://pirate.shu.edu/~blackdav

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