Re: "temp" vs "my"

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Thanks! Knew I'd seen the concept of OUTER but couldn't remember the
keyword.

-y

On Wed, Oct 3, 2018 at 5:51 AM, Timo Paulssen <[email protected]> wrote:

> you can refer to the outer $v as OUTER::('$v'), that ought to help :)
> On 03/10/2018 08:10, yary wrote:
>
> Reading and playing with https://docs.perl6.org/routine/temp
>
> There's an example showing how temp is "dynamic" - that any jump outside =
a
> block restores the value. All well and good.
>
> Then I thought, what if I want a lexical temporary value- then use "my"-
> and this is all well and good:
>
> my $v =3D "original";
> {
>     my $v =3D "new one";
>     start {
>         say "[PROMISE] Value before block is left: `$v`";
>         sleep 1;
>         say "[PROMISE] Block was left while we slept; value is still `$v`=
";
>     }
>     sleep =C2=BD;
>     say "About to leave the block; value is `$v`";
> }
> say "Left the block; value is now `$v`";
> sleep 2;
>
> Then I thought, well, what if I want to initialize the inner $v with the
> outer $v.
>
> my $v =3D "original";
> {
>     my $v =3D $v; # "SORRY! Cannot use variable $v in declaration to
> initialize itself"
>     say "inner value is $v";
>     $v=3D "new one";
> ...
>
> Gentle reader, how would you succinctly solve this contrived example?
> Anything you like better than this?
>
> my $v =3D "original";
> given $v -> $v is copy {
>     say "inner value is $v"; # "original", good
>     $v=3D "new one";
> ....
>
> -y
>
>

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<div dir=3D"ltr">Thanks! Knew I&#39;d seen the concept of OUTER but couldn&=
#39;t remember the keyword.</div><div class=3D"gmail_extra"><br clear=3D"al=
l"><div><div class=3D"gmail_signature" data-smartmail=3D"gmail_signature">-=
y<br></div></div>
<br><div class=3D"gmail_quote">On Wed, Oct 3, 2018 at 5:51 AM, Timo Paulsse=
n <span dir=3D"ltr">&lt;<a href=3D"mailto:[email protected]" target=3D"_blan=
k">[email protected]</a>&gt;</span> wrote:<br><blockquote class=3D"gmail_quo=
te" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"=
>
 =20
   =20
 =20
  <div text=3D"#000000" bgcolor=3D"#FFFFFF">
    <p>you can refer to the outer $v as OUTER::(&#39;$v&#39;), that ought t=
o
      help :)<br>
    </p><div><div class=3D"h5">
    <div class=3D"m_4515692280833966869moz-cite-prefix">On 03/10/2018 08:10=
, yary wrote:<br>
    </div>
    <blockquote type=3D"cite">
     =20
      <div dir=3D"ltr">
        <div dir=3D"ltr">
          <div dir=3D"ltr">
            <div dir=3D"ltr">
              <div dir=3D"ltr">
                <div dir=3D"ltr">Reading and playing with=C2=A0<a href=3D"h=
ttps://docs.perl6.org/routine/temp" target=3D"_blank">https://docs.perl6.or=
g/<wbr>routine/temp</a></div>
                <div dir=3D"ltr"><br>
                </div>
                <div>There&#39;s an example showing how temp is &quot;dynam=
ic&quot; -
                  that any jump outside a block restores the value. All
                  well and good.</div>
                <div><br>
                </div>
                <div>Then I thought, what if I want a lexical temporary
                  value- then use &quot;my&quot;- and this is all well and =
good:</div>
                <div><br>
                </div>
                <div>
                  <div>my $v =3D &quot;original&quot;;</div>
                  <div>{</div>
                  <div>=C2=A0 =C2=A0 my $v =3D &quot;new one&quot;;</div>
                  <div>=C2=A0 =C2=A0 start {</div>
                  <div>=C2=A0 =C2=A0 =C2=A0 =C2=A0 say &quot;[PROMISE] Valu=
e before block is
                    left: `$v`&quot;;</div>
                  <div>=C2=A0 =C2=A0 =C2=A0 =C2=A0 sleep 1;</div>
                  <div>=C2=A0 =C2=A0 =C2=A0 =C2=A0 say &quot;[PROMISE] Bloc=
k was left while we
                    slept; value is still `$v`&quot;;</div>
                  <div>=C2=A0 =C2=A0 }</div>
                  <div>=C2=A0 =C2=A0 sleep =C2=BD;</div>
                  <div>=C2=A0 =C2=A0 say &quot;About to leave the block; va=
lue is
                    `$v`&quot;;</div>
                  <div>}</div>
                  <div>say &quot;Left the block; value is now `$v`&quot;;</=
div>
                  <div>sleep 2;</div>
                </div>
                <div><br>
                </div>
                <div>Then I thought, well, what if I want to initialize
                  the inner $v with the outer $v.</div>
                <div><br>
                </div>
                <div>
                  <div>my $v =3D &quot;original&quot;;</div>
                  <div>{</div>
                  <div>=C2=A0 =C2=A0 my $v =3D $v; # &quot;SORRY! Cannot us=
e variable $v
                    in declaration to initialize itself&quot;</div>
                  <div>=C2=A0 =C2=A0 say &quot;inner value is $v&quot;;</di=
v>
                  <div>=C2=A0 =C2=A0 $v=3D &quot;new one&quot;;</div>
                </div>
                <div>...</div>
                <div><br>
                </div>
                <div>Gentle reader, how would you succinctly solve this
                  contrived example? Anything you like better than this?</d=
iv>
                <div><br>
                </div>
                <div>
                  <div>my $v =3D &quot;original&quot;;</div>
                  <div>given $v -&gt; $v is copy {</div>
                  <div>=C2=A0 =C2=A0 say &quot;inner value is $v&quot;; # &=
quot;original&quot;, good</div>
                  <div>=C2=A0 =C2=A0 $v=3D &quot;new one&quot;;</div>
                </div>
                <div>....</div>
                <div><br>
                </div>
                <div dir=3D"ltr">
                  <div>
                    <div class=3D"m_4515692280833966869gmail_signature">-y<=
br>
                    </div>
                  </div>
                </div>
              </div>
            </div>
          </div>
        </div>
      </div>
    </blockquote>
  </div></div></div>

</blockquote></div><br></div>

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