in reply to Re: Why doesn't % interpolate?
in thread Why doesn't % interpolate?

Given 

my $s = 'foo';
my @a = 1..10;
my $h = 1..10;

print "${s} @{a}"; # gives "foo 12345678910"

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Is there anything that would conflict with print "%{h}"; from producing the same output as print "@{[ %h ]}";?

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Re: Why doesn't % interpolate?
by Abigail-II (Bishop) on Apr 19, 2003 at 20:35 UTC
    Given that "${s}" is the same as "$s" and "@{a}" is the same as "@a", then yes. It would mean that "%{f}" is the same as "%f", which would break a lot of code, even without considering printf formats.

    Abigail

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      I'm not sure that follows. "is the same" for "${s}" & "@{a}" doesn't have to translate into "has to be the same" for "%{h}" does it? Perl has plenty on non-orthoganalities already.

      The "sigil{bareword}" syntax is specifically intended to disambiguate those cases where "sigil\w+" would be mis-interpreted 

      my $a = $year < 1999 ? 'pre-' :'post-';

print "In the context of ${a}millenium treatment of dates, $year becam
+e...";

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      Are there any other cases that would need special treatment if "%h" was designated as being equivalent to "@{[ %h ]}" except when used with the format strings for (s)printf where it would be necessary to disambiguate it by using "%s %3d %{h}"? I can't think of any, can you?

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        I'd say that 15 years of programming in Perl must have given us tons of code that uses %h, and expect it not to be interpolated as a hash. Suddenly changing the meaning of how strings are parsed would break that code.

        And it's not just printf formats that use lots of % characters. URIs use % to escape characters as well.

        But why make such a fuss? Why argue to break tons of programs just to save a few characters of typing for a not so very useful feature? The difference between "%{hash}" and "@{[%hash]}" is a whopping three characters.

        Abigail

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