On Wednesday, 15 April 2015 at 20:44:07 UTC, Ali Çehreli wrote:
> On 04/15/2015 12:09 PM, "=?UTF-8?B?Ik3DoXJjaW8=?= Martins\" <marcioapm@gmail.com>\"" wrote:
>> Hi!
>>
>> I use Appender a lot, and find it ugly to write this all the time to
>> efficiently construct strings:
>>
>> app.put("foo");
>> app.put(var);
>> app.put("bar");
>>
>> How about this instead?
>>
>> app.put("foo", var, "bar");
>
> Agreed.
>
> If a different name like putAll() is acceptable:
>
> void putAll(A, T...)(A a, T items)
> {
>     foreach (item; items){
>         a.put(item);
>     }
> }
>
> // ...
>
>     app.putAll("foo", var, "bar");
>
> Ali

This is great!
I would still call it just put(), close to writeln()'s interface. It shouldn't break any existing and compiling code, right?

On 4/15/15 1:51 PM, Messenger wrote:
> On Wednesday, 15 April 2015 at 19:09:42 UTC, Márcio Martins wrote:
>> Hi!
>>
>> I use Appender a lot, and find it ugly to write this all the time to
>> efficiently construct strings:
>>
>> app.put("foo");
>> app.put(var);
>> app.put("bar");
>>
>
> Sidetracking a bit, but when I started using Appender I was surprised to
> see that put didn't return a reference to the Appender itself. Had it
> done so, you could have chained your put calls very nicely.
>
> app.put("foo")
>     .put(var)
>     .put("bar")
>     .put(more)
>     .put("stuff");
>
> You can naturally write a small wrapper function that does this for you,
> but it still strikes me as odd. Sadly I imagine changing the return type
> would make the function signature mangle differently, breaking ABI
> compatibility.

Does ~= chain? -- Andrei

On Wednesday, 15 April 2015 at 20:59:25 UTC, Steven Schveighoffer wrote:
> On 4/15/15 4:51 PM, Messenger wrote:
>> On Wednesday, 15 April 2015 at 19:09:42 UTC, Márcio Martins wrote:
>>> Hi!
>>>
>>> I use Appender a lot, and find it ugly to write this all the time to
>>> efficiently construct strings:
>>>
>>> app.put("foo");
>>> app.put(var);
>>> app.put("bar");
>>>
>>
>> Sidetracking a bit, but when I started using Appender I was surprised to
>> see that put didn't return a reference to the Appender itself. Had it
>> done so, you could have chained your put calls very nicely.
>>
>> app.put("foo")
>>    .put(var)
>>    .put("bar")
>>    .put(more)
>>    .put("stuff");
>>
>> You can naturally write a small wrapper function that does this for you,
>> but it still strikes me as odd. Sadly I imagine changing the return type
>> would make the function signature mangle differently, breaking ABI
>> compatibility.
>
> with(app)
> {
>    put(var);
>    put("bar");
>    put(more);
>    put("stuff");
> }
>
> -Steve

With all the excitement about chaining and ufcs, the with statement is often overlooked.

Márcio Martins:

> app.put("foo");
> app.put(var);
> app.put("bar");

I'd like put() to accept a lazy range...

Bye,
bearophile

On Wednesday, 15 April 2015 at 20:40:04 UTC, Márcio Martins wrote:
> I guess chain could work in some cases, and are not that bad on the aesthetic side, I supposed. However having to include std.range just for that, and more importantly, all parameters having to be the same type, as opposed to just being "appendable".
>
> Creating an array inline is also not an option as I generally don't like to trade aesthetics <=> efficiency.

I think this works:

import std.range : only;
app.put(only("foo", var, "bar"));

http://dlang.org/phobos/std_range.html#.only

On Thursday, 16 April 2015 at 03:53:56 UTC, Andrei Alexandrescu wrote:
>> Sidetracking a bit, but when I started using Appender I was surprised to
>> see that put didn't return a reference to the Appender itself. Had it
>> done so, you could have chained your put calls very nicely.
>>
>> app.put("foo")
>>    .put(var)
>>    .put("bar")
>>    .put(more)
>>    .put("stuff");
>>
>> You can naturally write a small wrapper function that does this for you,
>> but it still strikes me as odd. Sadly I imagine changing the return type
>> would make the function signature mangle differently, breaking ABI
>> compatibility.
>
> Does ~= chain? -- Andrei

I'm not sure I understand.

Appender!string app;

app ~= "hello"
    ~= " "
    ~= "kitty";

--> Error: Cannot modify '" "'

Is the order of evaluation not such that this becomes app ~= ("hello" ~= (" " ~= "kitty"))?

On Thu, 16 Apr 2015 21:58:43 +0000, Messenger wrote:

> Appender!string app;
> 
> app ~= "hello"
>      ~= " "
>      ~= "kitty";
> 
> --> Error: Cannot modify '" "'
> 
> Is the order of evaluation not such that this becomes app ~= ("hello" ~=
> (" " ~= "kitty"))?

yes, assign is right associative.

On Wednesday, 15 April 2015 at 20:44:07 UTC, Ali Çehreli wrote:
> On 04/15/2015 12:09 PM, "=?UTF-8?B?Ik3DoXJjaW8=?= Martins\" <marcioapm@gmail.com>\"" wrote:
>> Hi!
>>
>> I use Appender a lot, and find it ugly to write this all the time to
>> efficiently construct strings:
>>
>> app.put("foo");
>> app.put(var);
>> app.put("bar");
>>
>> How about this instead?
>>
>> app.put("foo", var, "bar");
>
> Agreed.
>
> If a different name like putAll() is acceptable:
>
> void putAll(A, T...)(A a, T items)
> {
>     foreach (item; items){
>         a.put(item);
>     }
> }
>
> // ...
>
>     app.putAll("foo", var, "bar");

A hypothetical variadic put method would have the advantage over this in that it could could calculate the total length and preallocate for all arguments in one go.

On 16/04/2015 18:25, Nick Treleaven wrote:
> I think this works:
>
> import std.range : only;
> app.put(only("foo", var, "bar"));

OK, that doesn't work, and an array doesn't either (which was my assumption):

  app.put(["foo", var, "bar"]); // NG

If it had, I thought only might be more efficient than chain, but I could be wrong.