Revisit the String template syntax

[forax at univ-mlv.fr]

----- Original Message -----
> From: "Brian Goetz" <brian.goetz at oracle.com>
> To: "Remi Forax" <forax at univ-mlv.fr>
> Cc: "amber-spec-experts" <amber-spec-experts at openjdk.org>
> Sent: Wednesday, April 12, 2023 6:21:38 PM
> Subject: Re: Revisit the String template syntax

> The backslash syntax is objectively better than the dollar-sign syntax, which is
> why we selected it in the first place.  Reasons included:
> 
> - Today, “${name}” is a valid string literal, whereas “\{name}” is not.
> - The language already has an escaping mechanism for string contexts; using the
> one we have is preferable to inventing another one.
> - Dollar signs will appear in string context fairly regularly, and therefore
> would need yet more escaping.
> 
> We knew people would say “why don’t you ‘just’ do what ${MyFavoriteLanguage}
> does”, but this isn’t a reason to reconsider; the fact that other languages
> have continued to use the dollar-sign convention was well in evidence when the
> initial design choices were made, and there are no new arguments to support
> revisiting this question.
> 
> Whether to use braces or parens or brackets is largely an arbitrary choice, but
> I don’t see a lot of reason to recall this already-sailing ship.


I believe that the backslash syntax is better if we were in 1995, trying to design Java but since then, the dollar-sign syntax have been the go to syntax for string interpolation in the Java ecosystem. That's why actual most of the Java developers prefer the dollar-sign syntax to the backslash syntax (at least the one at Devoxx France i've asked), because they to not have to reconfigure their brain to recognize a new syntax.

Rémi

> 
> 
> 
>> On Apr 11, 2023, at 2:32 PM, Remi Forax <forax at univ-mlv.fr> wrote:
>> 
>> I've promoted this email to amber-spec-experts given that several people on the
>> internet and offline have said more or less the same thing.
>> 
>> Even if it's not for 21, now that a string template is always prefixed by a
>> template processor, the part in between quote does not need to rely on
>> backslash '\' anymore.
>> 
>> Should we still keep the current syntax \{...} or should we go to the more usual
>> ${...} syntax ?
>> 
>> regards,
>> Rémi
>> 
>> ----- Original Message -----
>>> From: "Octavia Togami" <octavia.togami at gmail.com>
>>> To: "amber-spec-comments" <amber-spec-comments at openjdk.org>
>>> Sent: Tuesday, April 11, 2023 1:39:20 AM
>>> Subject: Syntax question for JEP 430: String Templates
>> 
>>> Hi,
>>> 
>>> I was reading this portion of the alternatives section:
>>> 
>>>> For the syntax of embedded expressions we considered using ${...}, but that
>>>> would require a tag on string templates (either a prefix or a delimiter other
>>>> than ") to avoid conflicts with legacy code.
>>> 
>>> And it seems that this is no longer a valid reason, as per [1] there
>>> is always a required prefix anyways. Is there another reason to avoid
>>> using this syntax now?
>>> 
>>> Thanks,
>>> Octavia
>>> 
>>> [1]:
> >> https://mail.openjdk.org/pipermail/amber-spec-experts/2022-October/003631.html