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<font size="4"><font face="monospace">You seem to have a very
strange notion of what "works" means. These all work just
fine. No one is suggesting that local and "shared" variables
are unified. If you find it confusing to teach fields early,
then wait -- that's one of the choices. <br>
</font></font><br>
<blockquote type="cite">
<div>Scope rules are different, being static is different,
initialization rules are different, inference rules are
different, even colors in IDEs are different.<br data-mce-bogus="1">
</div>
</blockquote>
<br>
Correct, and well understood. Your point? <br>
<br>
<blockquote type="cite">
<div>You did, by re-using the term "variables" for both local
variable and fields.<br data-mce-bogus="1">
</div>
</blockquote>
<br>
Sorry, no. They are both variables, but they are different sorts.
Just like "instance vs static" variables, or "final vs mutable"
variables. They are all variables (they have a name, and a type,
and hold a value), and yet they each have different characteristics
(and the characteristics can be combined; you can have shared final
static variables, and local mutable variables, and....)<br>
<br>
I think you're taking a "I would prefer it work this way" and
bootstrapping it into "the alternative is broken" (that's what
"doesn't work" means.) You should know by now that this is the best
way to not have your arguments taken seriously! <br>
<br>
<br>
<br>
<div class="moz-cite-prefix">On 2/20/2023 4:38 PM, <a class="moz-txt-link-abbreviated" href="mailto:forax@univ-mlv.fr">forax@univ-mlv.fr</a>
wrote:<br>
</div>
<blockquote type="cite" cite="mid:1063786217.26511085.1676929092386.JavaMail.zimbra@u-pem.fr">
<div style="font-family: arial, helvetica, sans-serif; font-size:
12pt; color: #000000">
<div><br>
</div>
<div><br>
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<hr id="zwchr" data-marker="__DIVIDER__">
<div data-marker="__HEADERS__">
<blockquote style="border-left:2px solid
#1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><b>From:
</b>"Brian Goetz" <a class="moz-txt-link-rfc2396E" href="mailto:brian.goetz@oracle.com"><brian.goetz@oracle.com></a><br>
<b>To: </b>"Remi Forax" <a class="moz-txt-link-rfc2396E" href="mailto:forax@univ-mlv.fr"><forax@univ-mlv.fr></a><br>
<b>Cc: </b>"Ron Pressler" <a class="moz-txt-link-rfc2396E" href="mailto:ron.pressler@oracle.com"><ron.pressler@oracle.com></a>,
"Dan Heidinga" <a class="moz-txt-link-rfc2396E" href="mailto:heidinga@redhat.com"><heidinga@redhat.com></a>,
"amber-spec-experts" <a class="moz-txt-link-rfc2396E" href="mailto:amber-spec-experts@openjdk.org"><amber-spec-experts@openjdk.org></a><br>
<b>Sent: </b>Monday, February 20, 2023 9:33:34 PM<br>
<b>Subject: </b>Re: Implicit Record Was: JEP draft:
Implicit Classes and Enhanced Main Methods (Preview)<br>
</blockquote>
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<blockquote cite="mid:235253077.26502897.1676924374598.JavaMail.zimbra@u-pem.fr">
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<div>As i said earlier, it does not work because
fields and local variables have different semantics,<br>
</div>
<div>fields are initialized with a default value while
local variables need to be initialized before use.<br>
</div>
<div>So the curtain is just a veil that will be
pierced by any students moving declarations around.</div>
</div>
</div>
</blockquote>
<br>
Of course it "works", it just might not work how you would
prefer it to.</blockquote>
<div><br>
</div>
<div> var greetings = 0;<br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
<div>does not work,<br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
<div> void main() {<br data-mce-bogus="1">
</div>
<div> int greetings;<br data-mce-bogus="1">
</div>
<div> System.out.println(greetings);<br data-mce-bogus="1">
</div>
<div> }<br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
<div>does not work,<br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
<div>
<div> void main() {</div>
<div> static int greetings;</div>
<div> System.out.println(greetings);</div>
<div> }</div>
<div><br>
</div>
<div>does not work,</div>
</div>
<div><br data-mce-bogus="1">
</div>
<div> void main() {<br data-mce-bogus="1">
</div>
<div> int greetings = 0;<br data-mce-bogus="1">
</div>
<div> for(;;) {<br data-mce-bogus="1">
</div>
<div> int greetings = 0;<br data-mce-bogus="1">
</div>
<div> }<br data-mce-bogus="1">
</div>
<div> }<br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
<div>does not work too.<br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
<div>Scope rules are different, being static is different,
initialization rules are different, inference rules are
different, even colors in IDEs are different.<br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
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<br>
<br>
Prior to learning about fields, the user can perceive local
variables (declared in a method) and "shared" variables
(accessible to all members of the class.) They can learn
about their characteristics. Then, when they learn about
classes and fields and accessibility, they can learn that
the variables they were calling "shared" are really fields.
The distinction between locals and fields is there from the
beginning, though for most use cases, they will not notice
the difference. When they're ready to learn the fine
differences, there's not anything to unlearn. <br>
<br>
<blockquote cite="mid:235253077.26502897.1676924374598.JavaMail.zimbra@u-pem.fr">
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<div>From my personal experience, unifying local
variable and field leads to more pain than gain,
mostly because local </div>
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<br>
Who said anything about unification of fields and locals?
Where did you get such an idea that this is what is being
proposed? </blockquote>
<div><br>
</div>
<div>You did, by re-using the term "variables" for both local
variable and fields.<br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
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<br>
First students will learn about statements. Then they will
probably learn about local variables. They can be taught
that they disappear when the method exits, and each
invocation of the method gets a fresh copy. Then they can
learn about multiple methods, and then that there are
variables that can be shared across methods and retain their
values across method invocations, and while their
declaration syntax is the same (they're both variables,
after all), the _place_ in which they are declared is
different (which is what makes them shared), and shared
variables have slightly different characteristics (though
not so different they have to learn this immediately). They
can learn the characteristics of shared variables when it
makes sense to teach this. And when the curtain is pulled
back, they learn all fields have the characteristics of
these shared variables. </blockquote>
<div><br>
</div>
<div>Record components behave as you said, they have slightly
different characteristics than local variables and it's hard
to not notice the difference syntactically.<br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
<div>record Hello(String name) {<br data-mce-bogus="1">
</div>
<div> void hello() {<br data-mce-bogus="1">
</div>
<div> System.out.println("hello " + name);<br data-mce-bogus="1">
</div>
<div> }<br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
<div> void bonjour() {<br data-mce-bogus="1">
</div>
<div> System.out.println("bonjour " + name);<br data-mce-bogus="1">
</div>
<div> }<br data-mce-bogus="1">
</div>
<div>}<br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
<div>Class fields are far more different than just the
lifetime but have a very similar syntax.</div>
<div><br data-mce-bogus="1">
</div>
<div>Rémi<br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
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