Re^10: Shouldn't references be readonly? (UPDATED)

in reply to Re^9: Shouldn't references be readonly?
in thread Shouldn't LITERAL references be readonly? (updated)

sure see Re^6: Shouldn't references be readonly?

  DB<76> sub change { $_[0] = 666 }

  DB<77> $a=42

  DB<78> change($a)

  DB<79> p $a
666
  DB<80> change(42)
Modification of a read-only value attempted at (eval 86)[c:/Perl_524/l
+ib/perl5db.pl:737] line 2.

  DB<81>
[download]

still "lame"?

Cheers Rolf
_{(addicted to the Perl Programming Language :)

Wikisyntax for the Monastery}

update

BUT!!!

  DB<81> sub change_arr { $_[0] = [666] }

  DB<82> $a=[42]

  DB<83> change_arr($a)

  DB<84> x $a
0  ARRAY(0x3363180)
   0  666
  DB<85> change_arr([42]) #NO ERROR???

  DB<86>
[download]

Comment on Re^10: Shouldn't references be readonly? (UPDATED) Select or Download Code

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Re^11: Shouldn't references be readonly? by jo37 (Deacon) on Aug 05, 2020 at 19:48 UTC
This is no answer to my question. My point is: however created, an alias is a reference to something put into a slot of a symbol table entry. I do not see any evidence in your examples against this claim. UPDATE And then again, a de-referenced reference should behave similar to an alias. AFAICS it does. Greetings, -jo `$gryYup$d0ylprbpriprrYpkJl2xyl~rzg??P~5lp2hyl0p$`	[reply]
Re^12: Shouldn't references be readonly? by LanX (Saint) on Aug 05, 2020 at 20:18 UTC
> put into a slot of a symbol table entry. An alias is always a variable true, that's an obvious no-brainer. But typeglob mechanisms are only a part of the way to create them. Especially in `for my $a (@a) { ... }` there is no symbol table entry like you claimed. `my $a` is a private variable and an alias. And newer Perl versions allow activating the feature for refaliasing too, again no symbol table. Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery}	[reply] [d/l] [select]
Re^13: Shouldn't references be readonly? by jo37 (Deacon) on Aug 06, 2020 at 07:15 UTC
Accepted. Greetings, -jo `$gryYup$d0ylprbpriprrYpkJl2xyl~rzg??P~5lp2hyl0p$`	[reply]
Re^14: Shouldn't references be readonly? by LanX (Saint) on Aug 07, 2020 at 12:23 UTC

In Section Seekers of Perl Wisdom