Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl-Sensitive Sunglasses

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??

As a significant example of why flags can be messy, check this particularly thorny source code.

I needed to use that module and I found out that it was faulty. I tried to fix it, but its logic eluded me. I contacted the author, who didn't do anything, and therefore I wrote my own parser using a rather different approach.

This module is supposed to parse chess games. The problem in this code is that it skips the last game in each file it parses. I was able to spot where the problem is. As for fixing it using the same labyrinth of flags system, I simply couldn't.

## ## WARNING! broken code ahead! ## my $FLAG=1; my $GAME=0; ## ## ... snip ## sub ReadGame { my $self=shift; my $continue=1; $self->_init(); do { if ( $continue == 2 ) { $continue = 0 } if ( $LINE =~/\[(.*)\]/ ) { my $line=$1; my ($key,$val,$junk)=split(/"/,$line); $key=~s/ $//g, $self->{$key}=$val; $GAME=0; } elsif ( $LINE !~/^$/) { $self->{Game}.=$LINE; $GAME=1; } elsif ( $GAME == 1 ) { $FLAG=0; } $LINE=<FICPGN>; if ( eof(FICPGN) && $continue == 1 ) { $continue = 2 } $LINE=~s/\r//; } while ( $FLAG==1 ); return ( $continue ) ; }
This code uses not one but THREE flags, transforming a would-be OOP module into a peculiar example of spaghetti code.
_ _ _ _ (_|| | |(_|>< _|

In reply to Re: Flag variables by gmax
in thread Flag variables by oakbox

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

  • 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 or How to display code and escape characters are good places to start.
Log In?

What's my password?
Create A New User
Domain Nodelet?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others drinking their drinks and smoking their pipes about the Monastery: (3)
As of 2021-08-02 00:42 GMT
Find Nodes?
    Voting Booth?
    My primary motivation for participating at PerlMonks is: (Choices in context)

    Results (16 votes). Check out past polls.