in reply to Why Perl gets confused here?

You have som extra parens.
Here is how the code is being interpreted: 
substr(substr($p, 0, 1) = '123', 0, 1) = 'x';
substr((substr($q, 0, 1)) = '123', 0, 1) = 'x';

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Re^2: Why Perl gets confused here?
by Anonymous Monk on Oct 26, 2017 at 20:54 UTC
    i dont think extra parens kill lvalues 
    $ perl -le 'sub x:lvalue{$a} x="y";print$a'
y
$ perl -le 'sub x:lvalue{$a} (x)="y";print$a'
y

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      $ perl -le'sub x:lvalue{$a} print scalar( x="y" );'
y

$ perl -le'sub x:lvalue{$a} print scalar( (x)="y" );'
1

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