placeholders without printf?

Urthas has asked for the wisdom of the Perl Monks concerning the following question:

Hello Monks,

Consider the following code:

$bar = "Hello %s world!\n";

if ($bar =~ m/(Hello)/) {
    $foo = lc $1;
    $foo =~ s/h/j/;
    printf $bar, $foo; # prints "Hello jello world!"
}
[download]

Now consider this twist on the idea of a placeholder:

$bar = "Hello $foo world!\n";

if ($bar =~ m/(Hello)/) {
    $foo = lc $1;
    $foo =~ s/h/j/;
    print "$foo\n";    # prints "jello"
    print $bar;        # prints "Hello  world!"
}
[download]

Can I coerce Perl to DWIM? If so, how?

Thanks.

Comment on placeholders without printf? Select or Download Code

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Re: placeholders without printf? by ikegami (Patriarch) on Jan 23, 2010 at 03:29 UTC
In both snippets, what `$bar` contains is a template. You're looking for a template system. String::Interpolate's interface is a bit weird, but it supports templates like the one you have in your second snippet.	[reply] [d/l]
Re^2: placeholders without printf? by Urthas (Novice) on Jan 23, 2010 at 04:17 UTC
String::Interpolate's interface is a bit weird You weren't kidding. O.o Thanks again.	[reply]
Re: placeholders without printf? by Anonymous Monk on Jan 23, 2010 at 02:18 UTC
"interpolation". Interpolating backreferences in an eval, reinterpolation of regexp (and strings?), Evaluating $1 construct in literal replacement expression, String::Interpolate, String::Interpolate::RE	[reply]
Re: placeholders without printf? by graff (Chancellor) on Jan 23, 2010 at 16:38 UTC
I haven't tried String::Interpolate myself, but I've used Template a fair bit. It might be overkill for what you want to do, but basic usage is a pretty quick study -- e.g.: `perl -MTemplate -e '$t="Hello [% foo %] world\n"; $T=Template->new(); +$foo="whatever"; $T->process(\$t, {foo=>$foo})'` [download] If you would like to do things like conditionals and loops within the template, then this is a really nice package.	[reply] [d/l]