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in reply to Modules to reduce syntax?

> $ref->{'foo'}{$bar}

and

> ref[foo].bar

are definitely not the same in JavaScript

Cheers Rolf
(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery

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Re^2: Modules to reduce syntax?
by LanX (Sage) on Dec 22, 2021 at 14:44 UTC
    It's not clear to me what you want, since your code is wrong.

    Here the correct analogous:

    $ref->{foo}{$bar}

    (NB: autoquoting of key "foo" !)

    is

    demo in the JS console

    >> ref={foo: {x:42}} Object { foo: {} } >> bar="x" "x" >> ref.foo[bar] 42 >> ref['foo'][bar] 42

    as a side note, $ is a legal identifier in JS so you can also write

    >> $ref={foo: {x:42}} Object { foo: {} } >> $ref['foo'][$bar] 42

    update

    demo in the Perl debugger

    DB<3> $ref = {foo=> { x => 42 } } DB<4> $bar = "x" DB<5> p $ref->{foo}{$bar} 42 DB<6> p $$ref{foo}{$bar} 42

    update

    DB<11> use experimental 'refaliasing'; \%ref = $ref DB<12> p $ref{foo}{$bar} 42

    Cheers Rolf
    (addicted to the Perl Programming Language :)
    Wikisyntax for the Monastery

      You can't get rid of the sigils $%@ in Perl, because of conflicts with barewords which have many other meanings and the many bultin commands which depend on sigils.

      But this last example of aliasing a list-form and hashref-form \%hsh = $hsh could be simplified, such that the deref -> isn't needed anymore.

      use Keyword::Simple to define a new command like e.g. var or let and any

      var %hsh = LIST;

      is translated to

      my $hsh = \ my %hsh; %hsh = LIST;

      This is not too hard to implement, because you don't need to parse LIST in advance (which could be arbitrary Perl code)

      Like this explicit dereferencing with -> would be "simplified" away.

      Demo:

      DB<27> sub LIST { foo => { x => 42 } } DB<28> $bar ='x' DB<29> my $hsh = \ my %hsh; %hsh = LIST; \\ cont: say $hsh{foo}{$bar} 42

      Of course that way you'd loose the ability to have $ident and %ident in different namespaces, but that's often considered bad style anyway.

      And passing of hash-refs, like with function-parameters wouldn't be that easy without additional \ref-operation

      sub func { var (\%hsh,\@arr) = @_; }

      because otherwise var couldn't tell if a $scalar is meant to be aliased to a %hash or an @array

      sub func { var ($hsh,$arr) = @_; # ??? }

      tho you might be able simplify the syntax in many cases with

      sub func { var \(%hsh,@arr) = @_; }

      HTH! :)

      Cheers Rolf
      (addicted to the Perl Programming Language :)
      Wikisyntax for the Monastery