I've become persuaded that the current behavior should be kept. It is deducible from operator precedence and, once known, is not the cause of any great confusion.

What will be the effect of the proposed 'fix' on constructions like this? 

{
    my $foo = 'ABC-2N322-850103';
    sub prefix () :lvalue {
        substr $foo, 0, index( $foo, '-')
    }
}

[download]
Will the compiler keep the old value from the index? Does the associativity of assignment change? How is prefix() to know whether it is in lvalue position in a call? Any such change needs to try these things.

Update: Actually, the code above has a surprise in it, anyway. The result of the index call is kept instead of evaluated a second time: 

{
    my $foo = 'ABC-2N322-850103';
    sub prefix () :lvalue {
        substr $foo, 0, index( $foo, '-')
    }
    sub foo () { $foo }
}
print foo, $/;
my $bar = prefix = 'DEFG';
print $bar, $/
print foo, $/;
__END__
output:
ABC-2N322-850103
DEF
DEFG-2N322-850103

[download]

After Compline,
Zaxo

In reply to Re: lvalue substring oddities by Zaxo
in thread lvalue substring oddities by ysth

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