I am not even sure what kind of complicated code patterns may exist in a perl script.

Classic example of "only perl can parse Perl" (based heavily on tye's example here):

BEGIN { eval( rand>0.5 ? 'sub foo () {}' : 'sub foo {}' ) }
foo / # /;
42;

[download]

That's perfectly valid Perl code even under strict. Run that though B::Deparse a few times, and sometimes you'll get

foo(/ # /);
'???';

[download]

and sometimes

&foo() / 42;

[download]

In other words, sometimes it's a function call to which the result of a regex is being passed followed by a constant (that gets optimized away), and sometimes it's the return value of a function call, followed by a division operator, a comment, and the divisor. Which it is depends entirely on a random number that changes from run to run, and the result can't be known until the perl binary executes the first line of Perl code; doing the same with a static parse (without executing code) is impossible.

I need to come up with a logic that can interpret a line of complex perl code and remove comments and spaces in such a way that it won't break the code.

Perl Cannot Be Parsed: A Formal Proof

The closest thing to a static Perl parser is PPI (and perhaps PPR; Update 2: and new: Guacamole), and marto already pointed you to one module based on it; see also Perl::Squish. Update: You could also look at Perl::Tidy. Update 3: I think RPerl also implements its own parser.

In reply to Re: Perl script compressor by haukex
in thread Perl script compressor by harangzsolt33

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.