What about:

struct String {
	string items;
	alias items this;
}

And add the needed functions you wish to have in string and it will still work in existing functions that operate on immutable(char)[]

On 07/19/2010 06:51 PM, Jesse Phillips wrote:
> What about:
>
> struct String {
> 	string items;
> 	alias items this;
> }
>
> And add the needed functions you wish to have in string and it will still work in existing functions that operate on immutable(char)[]

Fortunately you can essentially achieve the above by simply writing free functions that take a string or a ref string as their first argument. Then you can use str.foo(args) as an alternative for foo(str, args).

Andrei

On Tue, 20 Jul 2010 01:51:51 +0200, Jesse Phillips <jessekphillips+d@gmail.com> wrote:

> What about:
>
> struct String {
> 	string items;
> 	alias items this;
> }
>
> And add the needed functions you wish to have in string and it will still work in existing functions that operate on immutable(char)[]

You shouldn't need to do that:

string strstr(string haystack, string needle);

can be used as:

string s;
s.strstr("needle");

so you can add "methods" to a string or whatever just by defining functions.

-Rory

On Mon, 19 Jul 2010 20:26:47 -0400, Andrei Alexandrescu <SeeWebsiteForEmail@erdani.org> wrote:

> On 07/19/2010 06:51 PM, Jesse Phillips wrote:
>> What about:
>>
>> struct String {
>> 	string items;
>> 	alias items this;
>> }
>>
>> And add the needed functions you wish to have in string and it will still work in existing functions that operate on immutable(char)[]
>
> Fortunately you can essentially achieve the above by simply writing free functions that take a string or a ref string as their first argument. Then you can use str.foo(args) as an alternative for foo(str, args).

How do we make this work?

auto str = "hello world";
foreach(c; str)
   assert(is(typeof(c) == dchar));

-Steve

On Tue, 20 Jul 2010 16:08:06 +0200, Jesse Phillips <jesse.k.phillips@gmail.com> wrote:

> But then you can't overload operators.
>
> On Tue, Jul 20, 2010 at 12:54 AM, Rory McGuire <rmcguire@neonova.co.za> wrote:
>> On Tue, 20 Jul 2010 01:51:51 +0200, Jesse Phillips
>> <jessekphillips+d@gmail.com> wrote:
>>
>>> What about:
>>>
>>> struct String {
>>>        string items;
>>>        alias items this;
>>> }
>>>
>>> And add the needed functions you wish to have in string and it will still
>>> work in existing functions that operate on immutable(char)[]
>>
>> You shouldn't need to do that:
>>
>> string strstr(string haystack, string needle);
>>
>> can be used as:
>>
>> string s;
>> s.strstr("needle");
>>
>> so you can add "methods" to a string or whatever just by defining functions.
>>
>> -Rory
>>
>
>
>

such as?

Steven Schveighoffer Wrote:
> 
> How do we make this work?
> 
> auto str = "hello world";
> foreach(c; str)
>     assert(is(typeof(c) == dchar));

foreach (dchar c; str)
    assert(...);

This feature has been in D for years.

On Tue, 20 Jul 2010 16:51:57 +0200, Rory McGuire <rmcguire@neonova.co.za> wrote:

> On Tue, 20 Jul 2010 16:08:06 +0200, Jesse Phillips <jesse.k.phillips@gmail.com> wrote:
>
>> But then you can't overload operators.
>>
>> On Tue, Jul 20, 2010 at 12:54 AM, Rory McGuire <rmcguire@neonova.co.za> wrote:
>>> On Tue, 20 Jul 2010 01:51:51 +0200, Jesse Phillips
>>> <jessekphillips+d@gmail.com> wrote:
>>>
>>>> What about:
>>>>
>>>> struct String {
>>>>        string items;
>>>>        alias items this;
>>>> }
>>>>
>>>> And add the needed functions you wish to have in string and it will still
>>>> work in existing functions that operate on immutable(char)[]
>>>
>>> You shouldn't need to do that:
>>>
>>> string strstr(string haystack, string needle);
>>>
>>> can be used as:
>>>
>>> string s;
>>> s.strstr("needle");
>>>
>>> so you can add "methods" to a string or whatever just by defining functions.
>>>
>>> -Rory
>>>
>>
>>
>>
>
> such as?

I mean is there not another way to do the same thing?

Rory McGuire <rmcguire@neonova.co.za> wrote:

[snip]

Rory, is there something wrong with your newsreader? I keep seeing your
posts as replies only to the top post.

-- 
Simen

Sean Kelly wrote:
> Steven Schveighoffer Wrote:
>> How do we make this work?
>>
>> auto str = "hello world";
>> foreach(c; str)
>>     assert(is(typeof(c) == dchar));
> 
> foreach (dchar c; str)
>     assert(...);
> 
> This feature has been in D for years.

	And what about this one:

void func(T) (T range) {
    foreach (elem; range)
        assert (is (typeof (elem) == ElementType!(T)));
}

func ("azerty");
auto a = [ 1, 2, 3, 4, 5];
func (a);

		Jerome
-- 
mailto:jeberger@free.fr
http://jeberger.free.fr
Jabber: jeberger@jabber.fr

On Tue, 20 Jul 2010 11:02:57 -0400, Sean Kelly <sean@invisibleduck.org> wrote:

> Steven Schveighoffer Wrote:
>>
>> How do we make this work?
>>
>> auto str = "hello world";
>> foreach(c; str)
>>     assert(is(typeof(c) == dchar));
>
> foreach (dchar c; str)
>     assert(...);
>
> This feature has been in D for years.

The omission of dchar is on purpose.  Phobos has characterized string as a bidirectional range of dchars.  For every range where I do:

foreach(e; range)

e is of the type of the range.  Except for char and wchar.  This schizophrenia of type induction is very bad for D, and it's a good argument of why strings should not simply be arrays.

-Steve