Re^2: Dereferencing code refs with & vs. ->()

&{ Block returning a code reference }

Are you saying that your code is littered with

&{do {
    # stuff here
    sub { ... };
}};
[download]

Because I'm not sure I like that syntax. It looks very obfuscated, to my eyes.

$$hash_ref{key} = $$array_ref[1];

Yes, I see that a lot in older code. The problem is that this syntax only works because of how tightly $ binds vs. {} or []. You're depending on the Perl parser always guessing correctly. Maybe I'm paranoid, but I prefer not making the parser guess my intention.

My criteria for good software:

Does it work?
Can someone else come in, make a change, and be reasonably certain no bugs were introduced?

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Re^3: Dereferencing code refs with & vs. ->() by Anonymous Monk on Sep 23, 2005 at 14:34 UTC
The official way of coding that is: `${$hash_ref}{key} = ${$array_ref}[1];` [download] You may leave of the braces if the content of the block is a simple variable. Perhaps you find that obfuscated, but that's actually the same rule as the first (optional) argument of `print`. The file handle is passed as a block, and taken as the result, but if the block is a simple variable, you may leave off the braces. If that isn't obfuscated, why is the code I presented obfuscated? Or is it that you aren't used to it, and call anything you aren't used to obfuscated? If you want to take a slice of a hash or an array, and all you have is a reference to it, how do you do it without being "obfuscated"? I write it as: `@$hash_ref{$key1, $key2, $key3};` [download] which follows naturally from accessing a single value: `$$hash_ref{$key1};` [download] But `@hash_ref->{$key1, $key2, $key3};` [download] doesn't work and nor does `$hash_ref->{$key1, $key2, $key3};` [download] And no, my code isn't littered with `&{do {... sub {...}}};` [download]	[reply] [d/l] [select]

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Re^3: Dereferencing code refs with & vs. ->()
by Anonymous Monk on Sep 23, 2005 at 14:34 UTC

${$hash_ref}{key} = ${$array_ref}[1];
[download]

print

If you want to take a slice of a hash or an array, and all you have is a reference to it, how do you do it without being "obfuscated"? I write it as:

    @$hash_ref{$key1, $key2, $key3};
[download]

    $$hash_ref{$key1};
[download]

    @hash_ref->{$key1, $key2, $key3};
[download]

    $hash_ref->{$key1, $key2, $key3};
[download]

And no, my code isn't littered with

    &{do {... sub {...}}};
[download]

[reply]
[d/l]
[select]