I wrote a trivial utility template for generating code string. This provides some easiness and viewability of metaprogramming. (This is currently used in my adaptTo.)

http://github.com/9rnsr/scrap/blob/master/expand/expand.d

Sample:
----
template GenFunc(string name)
{
  mixin(
    mixin(expand!q{
      int ${name}(){ return 10; }
    }));
  // result of expand! is:
  //   q{`int ` ~ name ~ `(){ return 10; }`}
}
mixin GenFunc!("test");   // generates function "test" returns int
unittest{
  assert(test() == 10);
}
----

expand!q{ codes... } parses D code string, and expands ${ expr } for embedding expr that is expression evaluated as string in compile-time.

do you think?

Kenji

This is great. It's funny I was thinking the same this morning before having looked over this message.

As expansion using $xxx is called interpolation in Perl and probably other scripting languages I suggest we call the facility "inter".

We can use it with writeln, which I think will be quite popular:

int a = 2;
string b = "hello";
writeln(mixin(inter!"I told you $a times: $str!"));

As shown above, I also suggest that we don't require {} when the expression is an identifier.

A debatable language change would allow us to eliminate "mixin", as it has been discussed in the newsgroup. A simpler and less dangerous change would be to make the paren optional:

writeln(mixin inter!"I told you $a times: $str!");



Andrei

On 10/31/10 10:50 AM, kenji hara wrote:
> I wrote a trivial utility template for generating code string. This provides some easiness and viewability of metaprogramming. (This is currently used in my adaptTo.)
>
> http://github.com/9rnsr/scrap/blob/master/expand/expand.d
>
> Sample:
> ----
> template GenFunc(string name)
> {
>    mixin(
>      mixin(expand!q{
>        int ${name}(){ return 10; }
>      }));
>    // result of expand! is:
>    //   q{`int ` ~ name ~ `(){ return 10; }`}
> }
> mixin GenFunc!("test");   // generates function "test" returns int
> unittest{
>    assert(test() == 10);
> }
> ----
>
> expand!q{ codes... } parses D code string, and expands ${ expr } for embedding expr that is expression evaluated as string in compile-time.
>
> do you think?
>
> Kenji
> _______________________________________________
> phobos mailing list
> phobos at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/phobos

Thanks for your response, Andrei.

I applied improvements that suggested from you.
- Identifier expression currently does not require braces.
- Interpolation expression is converted to string implicitly (with
std.conv.to!string(...)).

It is still not renamed to 'inter' in github, but I would to do it when committing to Phobos.

Kenji Hara

2010/11/2 Andrei Alexandrescu <andrei at erdani.com>:
> This is great. It's funny I was thinking the same this morning before having looked over this message.
>
> As expansion using $xxx is called interpolation in Perl and probably other scripting languages I suggest we call the facility "inter".
>
> We can use it with writeln, which I think will be quite popular:
>
> int a = 2;
> string b = "hello";
> writeln(mixin(inter!"I told you $a times: $str!"));
>
> As shown above, I also suggest that we don't require {} when the expression is an identifier.
>
> A debatable language change would allow us to eliminate "mixin", as it has been discussed in the newsgroup. A simpler and less dangerous change would be to make the paren optional:
>
> writeln(mixin inter!"I told you $a times: $str!");
>
>
>
> Andrei
>
> On 10/31/10 10:50 AM, kenji hara wrote:
>>
>> I wrote a trivial utility template for generating code string. This provides some easiness and viewability of metaprogramming. (This is currently used in my adaptTo.)
>>
>> http://github.com/9rnsr/scrap/blob/master/expand/expand.d
>>
>> Sample:
>> ----
>> template GenFunc(string name)
>> {
>> ? mixin(
>> ? ? mixin(expand!q{
>> ? ? ? int ${name}(){ return 10; }
>> ? ? }));
>> ? // result of expand! is:
>> ? // ? q{`int ` ~ name ~ `(){ return 10; }`}
>> }
>> mixin GenFunc!("test"); ? // generates function "test" returns int
>> unittest{
>> ? assert(test() == 10);
>> }
>> ----
>>
>> expand!q{ codes... } parses D code string, and expands ${ expr } for embedding expr that is expression evaluated as string in compile-time.
>>
>> do you think?
>>
>> Kenji
>> _______________________________________________
>> phobos mailing list
>> phobos at puremagic.com
>> http://lists.puremagic.com/mailman/listinfo/phobos
>
> _______________________________________________
> phobos mailing list
> phobos at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/phobos
>

Thanks, Kenji. All - ideas for a better name? "interp"? Full "interpolate"? Leave it as "expand"?

Andrei

On 11/2/10 5:40 AM, kenji hara wrote:
> Thanks for your response, Andrei.
>
> I applied improvements that suggested from you.
> - Identifier expression currently does not require braces.
> - Interpolation expression is converted to string implicitly (with
> std.conv.to!string(...)).
>
> It is still not renamed to 'inter' in github, but I would to do it when committing to Phobos.
>
> Kenji Hara
>
> 2010/11/2 Andrei Alexandrescu<andrei at erdani.com>:
>> This is great. It's funny I was thinking the same this morning before having looked over this message.
>>
>> As expansion using $xxx is called interpolation in Perl and probably other scripting languages I suggest we call the facility "inter".
>>
>> We can use it with writeln, which I think will be quite popular:
>>
>> int a = 2;
>> string b = "hello";
>> writeln(mixin(inter!"I told you $a times: $str!"));
>>
>> As shown above, I also suggest that we don't require {} when the expression is an identifier.
>>
>> A debatable language change would allow us to eliminate "mixin", as it has been discussed in the newsgroup. A simpler and less dangerous change would be to make the paren optional:
>>
>> writeln(mixin inter!"I told you $a times: $str!");
>>
>>
>>
>> Andrei
>>
>> On 10/31/10 10:50 AM, kenji hara wrote:
>>>
>>> I wrote a trivial utility template for generating code string. This provides some easiness and viewability of metaprogramming. (This is currently used in my adaptTo.)
>>>
>>> http://github.com/9rnsr/scrap/blob/master/expand/expand.d
>>>
>>> Sample:
>>> ----
>>> template GenFunc(string name)
>>> {
>>>    mixin(
>>>      mixin(expand!q{
>>>        int ${name}(){ return 10; }
>>>      }));
>>>    // result of expand! is:
>>>    //   q{`int ` ~ name ~ `(){ return 10; }`}
>>> }
>>> mixin GenFunc!("test");   // generates function "test" returns int
>>> unittest{
>>>    assert(test() == 10);
>>> }
>>> ----
>>>
>>> expand!q{ codes... } parses D code string, and expands ${ expr } for embedding expr that is expression evaluated as string in compile-time.
>>>
>>> do you think?
>>>
>>> Kenji
>>> _______________________________________________
>>> phobos mailing list
>>> phobos at puremagic.com
>>> http://lists.puremagic.com/mailman/listinfo/phobos
>>
>> _______________________________________________
>> phobos mailing list
>> phobos at puremagic.com
>> http://lists.puremagic.com/mailman/listinfo/phobos
>>
> _______________________________________________
> phobos mailing list
> phobos at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/phobos

One more thing - for efficiency, instead of using to!string, I suggest you use formattedWrite with "%s" as format string and an appender as writer.

Andrei

On 11/2/10 5:40 AM, kenji hara wrote:
> Thanks for your response, Andrei.
>
> I applied improvements that suggested from you.
> - Identifier expression currently does not require braces.
> - Interpolation expression is converted to string implicitly (with
> std.conv.to!string(...)).
>
> It is still not renamed to 'inter' in github, but I would to do it when committing to Phobos.
>
> Kenji Hara
>
> 2010/11/2 Andrei Alexandrescu<andrei at erdani.com>:
>> This is great. It's funny I was thinking the same this morning before having looked over this message.
>>
>> As expansion using $xxx is called interpolation in Perl and probably other scripting languages I suggest we call the facility "inter".
>>
>> We can use it with writeln, which I think will be quite popular:
>>
>> int a = 2;
>> string b = "hello";
>> writeln(mixin(inter!"I told you $a times: $str!"));
>>
>> As shown above, I also suggest that we don't require {} when the expression is an identifier.
>>
>> A debatable language change would allow us to eliminate "mixin", as it has been discussed in the newsgroup. A simpler and less dangerous change would be to make the paren optional:
>>
>> writeln(mixin inter!"I told you $a times: $str!");
>>
>>
>>
>> Andrei
>>
>> On 10/31/10 10:50 AM, kenji hara wrote:
>>>
>>> I wrote a trivial utility template for generating code string. This provides some easiness and viewability of metaprogramming. (This is currently used in my adaptTo.)
>>>
>>> http://github.com/9rnsr/scrap/blob/master/expand/expand.d
>>>
>>> Sample:
>>> ----
>>> template GenFunc(string name)
>>> {
>>>    mixin(
>>>      mixin(expand!q{
>>>        int ${name}(){ return 10; }
>>>      }));
>>>    // result of expand! is:
>>>    //   q{`int ` ~ name ~ `(){ return 10; }`}
>>> }
>>> mixin GenFunc!("test");   // generates function "test" returns int
>>> unittest{
>>>    assert(test() == 10);
>>> }
>>> ----
>>>
>>> expand!q{ codes... } parses D code string, and expands ${ expr } for embedding expr that is expression evaluated as string in compile-time.
>>>
>>> do you think?
>>>
>>> Kenji
>>> _______________________________________________
>>> phobos mailing list
>>> phobos at puremagic.com
>>> http://lists.puremagic.com/mailman/listinfo/phobos
>>
>> _______________________________________________
>> phobos mailing list
>> phobos at puremagic.com
>> http://lists.puremagic.com/mailman/listinfo/phobos
>>
> _______________________________________________
> phobos mailing list
> phobos at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/phobos

On Tue, 02 Nov 2010 10:03:23 -0400, Andrei Alexandrescu <andrei at erdani.com> wrote:

> Thanks, Kenji. All - ideas for a better name? "interp"? Full "interpolate"? Leave it as "expand"?
>
> Andrei

Well, "interpolate" and "interp" have mathematical connotations to me, so vote-- for those. Note that functionality of this seems very similar to both format and text:

enum int a = 10;
enum string op = "+";
static assert(mixin(expand!q{ ${a*2} ${op} 2 }) == q{ 20 + 2 });
vs.
static assert(Format!(" %s %s 2 ",a*2,op)) == q{ 20 + 2 });
vs.
static assert(text(" ",a*2," ",op," 2 ") == q{ 20 + 2 };

So maybe some variant of format would be appropriate: MixinFormat, mFormat, mText, FormatInPlace, etc, though these all seem clunky. MixinFormat would make a lot of sense if you could declare a template that's always a mixin, and could simply write MixinFormat!q{ ${a*2} ${op} 2 } instead of mixin(MixinFormat!q{ ${a*2} ${op} 2 }). As this syntax comes from perl, we could use that as a prefix: perlFormat / pFormat / perlText / pText.

Also, am I missing something with regard to the use cases of expand/inter? All the examples given in the documentation seem to be better served by either text or Format.

On Tue, 02 Nov 2010 09:03:23 -0500
Andrei Alexandrescu <andrei at erdani.com> wrote:

> Thanks, Kenji. All - ideas for a better name? "interp"? Full "interpolate"? Leave it as "expand"?

In my opinion, "inter" is far to vague. I would vote for full word if I had to vote ;-); at least with "interp" one has a chance to guess right...
By the way, some call these strings "variable strings": indeed, they have variable parts -- most commonly denoted by variable names.

Denis
-- -- -- -- -- -- --
vit esse estrany ?

spir.wikidot.com

I like some short name on clear meaning.

I googled "variable expansion" and "interpolation|interp" with some
language names.
There was no significant difference in result.

(I'm not a native English speaker. Please read follows with a grain of salt.)

"interp" may remind us "interpolation(=variable expansion)",
"interpolation(math)", and "interpreter".
On the other hand, "expand" is more general word than "interp".
So, I think that "interp" will be more better .

Kenji

2010/11/2 Andrei Alexandrescu <andrei at erdani.com>:
> Thanks, Kenji. All - ideas for a better name? "interp"? Full "interpolate"? Leave it as "expand"?
>
> Andrei
>
> On 11/2/10 5:40 AM, kenji hara wrote:
>>
>> Thanks for your response, Andrei.
>>
>> I applied improvements that suggested from you.
>> - Identifier expression currently does not require braces.
>> - Interpolation expression is converted to string implicitly (with
>> std.conv.to!string(...)).
>>
>> It is still not renamed to 'inter' in github, but I would to do it when committing to Phobos.
>>
>> Kenji Hara
>>
>> 2010/11/2 Andrei Alexandrescu<andrei at erdani.com>:
>>>
>>> This is great. It's funny I was thinking the same this morning before
>>> having
>>> looked over this message.
>>>
>>> As expansion using $xxx is called interpolation in Perl and probably
>>> other
>>> scripting languages I suggest we call the facility "inter".
>>>
>>> We can use it with writeln, which I think will be quite popular:
>>>
>>> int a = 2;
>>> string b = "hello";
>>> writeln(mixin(inter!"I told you $a times: $str!"));
>>>
>>> As shown above, I also suggest that we don't require {} when the
>>> expression
>>> is an identifier.
>>>
>>> A debatable language change would allow us to eliminate "mixin", as it
>>> has
>>> been discussed in the newsgroup. A simpler and less dangerous change
>>> would
>>> be to make the paren optional:
>>>
>>> writeln(mixin inter!"I told you $a times: $str!");
>>>
>>>
>>>
>>> Andrei
>>>
>>> On 10/31/10 10:50 AM, kenji hara wrote:
>>>>
>>>> I wrote a trivial utility template for generating code string. This provides some easiness and viewability of metaprogramming. (This is currently used in my adaptTo.)
>>>>
>>>> http://github.com/9rnsr/scrap/blob/master/expand/expand.d
>>>>
>>>> Sample:
>>>> ----
>>>> template GenFunc(string name)
>>>> {
>>>> ? mixin(
>>>> ? ? mixin(expand!q{
>>>> ? ? ? int ${name}(){ return 10; }
>>>> ? ? }));
>>>> ? // result of expand! is:
>>>> ? // ? q{`int ` ~ name ~ `(){ return 10; }`}
>>>> }
>>>> mixin GenFunc!("test"); ? // generates function "test" returns int
>>>> unittest{
>>>> ? assert(test() == 10);
>>>> }
>>>> ----
>>>>
>>>> expand!q{ codes... } parses D code string, and expands ${ expr } for embedding expr that is expression evaluated as string in compile-time.
>>>>
>>>> do you think?
>>>>
>>>> Kenji
>>>> _______________________________________________
>>>> phobos mailing list
>>>> phobos at puremagic.com
>>>> http://lists.puremagic.com/mailman/listinfo/phobos
>>>
>>> _______________________________________________
>>> phobos mailing list
>>> phobos at puremagic.com
>>> http://lists.puremagic.com/mailman/listinfo/phobos
>>>
>> _______________________________________________
>> phobos mailing list
>> phobos at puremagic.com
>> http://lists.puremagic.com/mailman/listinfo/phobos
>
> _______________________________________________
> phobos mailing list
> phobos at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/phobos
>

The definition of inter -- to bury a dead body in the ground :)

I don't think inter is right.

I like expand, it has precedence (e.g. expanding environment variables).

-Steve



----- Original Message ----
> From: Andrei Alexandrescu <andrei at erdani.com>
> 
> Thanks, Kenji. All - ideas for a better name? "interp"? Full "interpolate"?  Leave it as "expand"?

hm... I swore I saw inter, not interp.

I still think expand sounds better.  Interpolate to me doesn't sound right, it reminds me of image enhancement, not substitution.

-Steve



----- Original Message ----
> From: Steve Schveighoffer <schveiguy at yahoo.com>
> To: Discuss the phobos library for D <phobos at puremagic.com>
> Sent: Tue, November 2, 2010 11:57:10 AM
> Subject: Re: [phobos] expand for std.metastrings
> 
> The definition of inter -- to bury a dead body in the ground :)
> 
> I don't  think inter is right.
> 
> I like expand, it has precedence (e.g. expanding  environment variables).
> 
> -Steve
> 
> 
> 
> ----- Original Message  ----
> > From: Andrei Alexandrescu <andrei at erdani.com>
> > 
> >  Thanks, Kenji. All - ideas for a better name? "interp"? Full
> >  "interpolate"?  Leave it as "expand"?
> 
> 
> 
> 
> _______________________________________________
> phobos mailing list
> phobos at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/phobos
>