• bobef (13/13) Aug 11 2008 Hi, the suggestions is this:
• bearophile (4/7) Aug 11 2008 Why? Can you show/tell some purpose of it?
• Ary Borenszweig (4/13) Aug 11 2008 I think he can't have a reference to the second "a" method, because &A.a...
• BCS (5/20) Aug 11 2008 ouch!
• Jarrett Billingsley (4/24) Aug 11 2008 cast(uint function(char[]))&A.a
• BCS (9/21) Aug 12 2008 template FnWithThese(T...)
• Koroskin Denis (4/15) Aug 11 2008 Yeah, but how do you distinguish which one is first and which one is
• Michiel Helvensteijn (25/40) Aug 12 2008 There's a very complicated variation of this idea and a slightly less
• bobef (2/9) Aug 15 2008 Example: When you are using templates to bind someone else's native clas...

bobef <bobef nosmap-abv.bg> writes:

Hi, the suggestions is this:

In this case:

class A
{
  uint a(char[] b){}
  int a(int b){}
}

Make this syntax valid:

A.a[1]
A.a.length
etc

Regards,
bobef

bearophile <bearophileHUGS lycos.com> writes:

bobef Wrote:
 Make this syntax valid:
 A.a[1]
 A.a.length

Why? Can you show/tell some purpose of it?

Bye,
bearophile

Ary Borenszweig <ary esperanto.org.ar> writes:

bearophile a écrit :
 bobef Wrote:
 Make this syntax valid:
 A.a[1]
 A.a.length

 
 Why? Can you show/tell some purpose of it?
 
 Bye,
 bearophile


I think he can't have a reference to the second "a" method, because &A.a 
just returns the first one. So he's asking to treat "A.a" as an array of 
methods.

BCS <ao pathlink.com> writes:

Reply to Ary,

 bearophile a écrit :
 
 bobef Wrote:
 
 Make this syntax valid:
 A.a[1]
 A.a.length

 Why? Can you show/tell some purpose of it?
 
 Bye,
 bearophile

 I think he can't have a reference to the second "a" method, because
 &A.a just returns the first one. So he's asking to treat "A.a" as an
 array of methods.
 

ouch!

better solution

&A.a(char[])
&A.a(int)

"Jarrett Billingsley" <kb3ctd2 yahoo.com> writes:

"BCS" <ao pathlink.com> wrote in message 
news:55391cb3304918cac9d9f784829e news.digitalmars.com...
 Reply to Ary,

 bearophile a écrit :

 bobef Wrote:

 Make this syntax valid:
 A.a[1]
 A.a.length

 Why? Can you show/tell some purpose of it?

 Bye,
 bearophile

 I think he can't have a reference to the second "a" method, because
 &A.a just returns the first one. So he's asking to treat "A.a" as an
 array of methods.

 ouch!

 better solution

 &A.a(char[])
 &A.a(int)

cast(uint function(char[]))&A.a

already works, but is terribly unwieldy, I'll agree. 

BCS <ao pathlink.com> writes:

Reply to Jarrett,

 "BCS" <ao pathlink.com> wrote in message
 
 ouch!
 
 better solution
 
 &A.a(char[])
 &A.a(int)

 cast(uint function(char[]))&A.a
 
 already works, but is terribly unwieldy, I'll agree.
 

template FnWithThese(T...)
{
     R function(T) Args(R)(R function(T) fn){return fn;}
     R delegate(T) Args(R)(R delegate(T) fn){return fn;}
}

FnWithThese!(char[]).Args(&A.a)

(untested)

At least that's clearer what it's doing

"Koroskin Denis" <2korden gmail.com> writes:

On Tue, 12 Aug 2008 01:43:56 +0400, Ary Borenszweig <ary esperanto.org.ar>  
wrote:

 bearophile a écrit :
 bobef Wrote:
 Make this syntax valid:
 A.a[1]
 A.a.length

  Why? Can you show/tell some purpose of it?
  Bye,
 bearophile


 I think he can't have a reference to the second "a" method, because &A.a  
 just returns the first one. So he's asking to treat "A.a" as an array of  
 methods.

Yeah, but how do you distinguish which one is first and which one is  
second?

Michiel Helvensteijn <nomail please.com> writes:

bobef wrote:

 Hi, the suggestions is this:
 
 In this case:
 
 class A
 {
   uint a(char[] b){}
   int a(int b){}
 }
 
 Make this syntax valid:
 
 A.a[1]
 A.a.length
 etc

There's a very complicated variation of this idea and a slightly less
complicated one.

The less complicated variation: The index always has to be an expression
that can be easily evaluated at compile-time (like a literal or a
constant). That way, every member-reference can be fully qualified at
compile-time. However, if this is the behavior you want, you might as well
call the members A.a1 and A.a2. I believe the D template system allows you
to use a syntax like A.a!(1) and A.a!(2) in this case (though I haven't
used D in quite a while, so I'm not sure). And the .length property would
not be very useful in this variation.

So I'm guessing you are suggesting a more complicated variation, in which
the index can be any integer expression. The problem here is that the
compiler can not always know what to expect when A.a[i] is called. The
function might take or return incompatible types (like char[] vs. int).
Either you'd have to make sure the code at the call-site is compatible with
any value of 0 <= i < length, or you'd have to guarantee that i will have a
value such that the function-call is correct. This is not a condition that
the compiler will be able to verify, and an error might result in very
strange run-time behavior. I suppose you can work around this last problem
by assert()ing a compatible state of i before the call.

But I believe that in both cases the idea is more trouble than it's worth.
Can you give an example in which it might be useful?

-- 
Michiel

bobef <bobef nosmap-abv.bg> writes:

Michiel Helvensteijn Wrote:

 
 But I believe that in both cases the idea is more trouble than it's worth.
 Can you give an example in which it might be useful?
 
 -- 
 Michiel
 

Example: When you are using templates to bind someone else's native classes to
script classes and nobody calls their methods a1 a2. See minid binding library
for code example.