JEP445 meets JEP459

[Ian Darwin]

I see your main point but can't resist the odd quibble:

On 2/6/24 12:14, Brian Goetz wrote:
> Similar things have been suggested before, but there are two primary 
> concerns here that make it a "clever" but 
> unattractive-in-the-long-term direction.
>
> The main one is "the onramp should lead to the highway."  If we give a 
> special, magic way to print templated strings, but nothing else, this 
> is an easy incantation to teach, but it doesn't go very far.  If you 
> want to do even a little bit more (e.g., print to a file, or to 
> standard error, or just print out a string with no formatting, etc), 
> you have to switch to a completely different mechanism, 

A string with no formatting would be handled like any other, just as 
STR."Hello world" yields (redundantly) a string with no formatting.

Printing to a file is more complicated anyway as you don't usually get 
there without meeting IOException and try/catch or at least throws.

But yes, it is a different mechanism; as part of smoothing that out, 
students can initially be taught that PRINT."..." is "just a shortcut" 
for System.out.println(STR."..."); as a side benefit, they learn about 
this string template that can be used anywhere.

> and now you need to know TWO things and know when to use one or the 
> other.  It is a shortcut that becomes a "beginner's dialect" because 
> it does not lead smoothly to learning the "regular" language.
>
> Second, the possibility that a string template could have side-effects 
> instead of (or worse, in addition to) just taking the ingredients and 
> mixing them up into a composite thing makes the concept of string 
> templates more complicated.  While we can't prevent people from 
> sneaking side effects into their template processors, we shouldn't 
> encourage this, or suggest that all users have to work this into their 
> mental model. 
But this template processor, like STR itself, would be a final field in 
perhaps the StringTemplate class, imported automatically like STR. It is 
your processor, not theirs.
>
>
> So its possible, but I don't think its a good direction for the language.
It's your call. Thanks for the feedback. I'll withdraw the suggestion 
and hope that some day, some way can be found to simplify this 
particular "speed bump". I respect that the team always holds off until 
the best or "correct" way can be found.
>
> On 2/6/2024 11:54 AM, Ian Darwin wrote:
>> While experimenting with the String Template feature, it occurs to me 
>> that a relatively simple expansion of String Templates would pave 
>> over another of those speed bumps. Basically:
>>
>>     PRINT."Hello \{name}. Your balance is \{amount}";
>>
>> Indeed, the beginner who hasn't yet met string templates can use the 
>> degenerate case
>>
>>     PRINT."Hello world";
>>
>> and then later "need not discard what they learned in the early 
>> stages, but rather they see how it all fits within the larger picture."
>>
>> This compares favorably with, e.g., Python 3's
>>
>> print('Hello world') and
>>
>> print(f'Hello {name}, your balance is {balance}')
>>
>> This seems like a fairly obvious extension, so I ask: Do you already 
>> have such a thing up your collective sleeves or, if not, do you think 
>> it might be grounds for a JEP proposal?
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mail.openjdk.org/pipermail/amber-dev/attachments/20240206/feb7ad09/attachment.htm>