The code linked from this node simulates the behavior of a Perl hash, and then draws a picture of the resulting data structure. Here is an example output, demonstrating the layout of the following hash:

    %h = (     When =>  1,
                 in =>  2,
                the =>  3,
             course =>  4,
                 of =>  5,
              human =>  6,
             events =>  7,
                 it =>  8,
            becomes =>  9,     
          necessary => 10,
             for => 11,
                one => 12,
             people => 13,
         );
[download]

If you ask Perl to print out the keys in this hash with keys %h, you get the following list: (becomes necessary human people course in one When events of the is for), which as you can see is the order that the keys actually appear in the hash structure in the illustration.

Right now the module emits pic code, which tells the Unix pic program how to draw the diagram. pic is a little obscure. But I designed it so that it will be easy to subclass it and override a few methods (draw_start, draw_end, draw_bucket, draw_node) so that it renders the diagram in PostScript or with GD or whatever you prefer. Contributions will be welcome. Complete documentation is included, of course.

Download the module

Read the manual

View the source code

I didn't want to post the source code here because it was about 450 lines long.

---

---

• Are you posting in the right place? Check out Where do I post X? to know for sure.
• Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:

  <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>

• Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
• Want more info? How to link or How to display code and escape characters are good places to start.