I think you're going to be disappointed. You can't just take a result and get the function that generated that result or, for that matter, even get the variable name associated with a give variable. One way would be to store variable names in variables, combine them at will and eval the result. Personally, I think this will cause you grief, though.

my $bad_idea1 = '$var1';
my $bad_idea2 = '$var2';

my $var1 = 3;
my $var2 = 4;

my $equation = "$bad_idea1 + $bad_idea2";
print "$equation\n";
print eval $equation;

[download]

Here's an example of how things can go wrong:

my $bad_idea1 = '$var1';
my $bad_idea2 = '$var2';

my $var1 = 3;
my $var2 = 0;

my $equation = "$bad_idea1 / $bad_idea2";
print "$equation\n";
my $result = eval $equation;
if ( $@ ) {
    print $@;
} else {
    print $result;
}

[download]

Cheers,
Ovid

Join the Perlmonks Setiathome Group or just click on the the link and check out our stats.

In reply to (Ovid) Re: auto-escaping?? by Ovid
in thread auto-escaping?? by goonfest

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.