arity bug?

arity bug?

[Christoph]

Hi,

the following (with (2003-09-18) [i386-mingw32]
and (2003-10-03) [i386-mswin32])

---
p proc {|| 13 }.arity  # 0
p proc { 13 }.arity    # -1
---

looks like a bug to me?



/Christoph

Re: arity bug?

[ts]

>>>>> "C" == Christoph  <chr_news@gmx.net> writes:

C> p proc {|| 13 }.arity  # 0
C> p proc { 13 }.arity    # -1

svg% ruby -e 'a = proc { p 12 }; a[1,2,3]; b = proc {|| 13 }; b[1]'
12
-e:1: wrong number of arguments (1 for 0) (ArgumentError)
        from -e:1:in `[]'
        from -e:1
svg% 


Guy Decoux

Re: arity bug?

[Christoph]

"ts" wrote:
...
> svg% ruby -e 'a = proc { p 12 }; a[1,2,3]; b = proc {|| 13 }; b[1]'
> 12
> -e:1: wrong number of arguments (1 for 0) (ArgumentError)
>         from -e:1:in `[]'
>         from -e:1
> svg% 

I known that the calling convention is consistent with the arity 
but since there is no way of accessing the calling arguments
inside  a Proc call like 

proc {  p 12 }[12,13]


it feels that the arity of these Proc's is 0 and not the current -1.


/Christoph 

Re: arity bug?

[Yukihiro Matsumoto]

Hi,

In message "Re: arity bug?"
    on 03/10/06, "Christoph" <chr_news@gmx.net> writes:

|I known that the calling convention is consistent with the arity 
|but since there is no way of accessing the calling arguments
|inside  a Proc call like 
|
|proc {  p 12 }[12,13]
|
|it feels that the arity of these Proc's is 0 and not the current -1.

Why don't you specify parameters explicitly if you want to get the
argument.  Omitting parameters means "don't care".

							matz.

Re: arity bug?

[Christoph]

Yukihiro Matsumoto wrote:
..
> |proc {  p 12 }[12,13]
> |
> |it feels that the arity of these Proc's is 0 and not the current -1.
> 
> Why don't you specify parameters explicitly if you want to get the
> argument.  Omitting parameters means "don't care".

But if I don't provide explicit parameters at definition time 
I see little reason why it should be allowed to supply superfluous
parameters at calling time. 
Anyway it is no big deal (arity = -1 works fine in any occasion) and 
it probably worked like this for ages - I just was really surprised when
I finally tripped over this fact.

/Christoph