I think this is not treating 'equal preference' operators right. The expresion 16/4*2 should be considered as (16/4)*2, but your code produces 16/(4*2): 
$ perl parser.pl
16/4*2
{
          '/' => [
                   '16',
                   {
                     '*' => [
                              '4',
                              '2'
                            ]
                   }
                 ]
        }

[download]
A simple tweak of the precedence regex: 
my $precedence=[qr/(?:&&|\|\|)/,qr/(?:\+|-)/,qr/(?:\/|\*)/];

[download]
Will produce a better output: 
{
          '*' => [
                   {
                     '/' => [
                              '16',
                              '4'
                            ]
                   },
                   '2'
                 ]
        }

[download]
Edit: a further reading at perlop show me that '&&' precedes over '||', so regex should be: 
my $precedence=[qr/(?:\/|\*)/,qr/(?:\+|-)/,qr/&&/,qr/|\|\|/];

[download]

In reply to Re: Perl Parsing Based on Supplied Precedence by wirito
in thread Perl Parsing Based on Supplied Precedence by protist

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.