murugu has asked for the wisdom of the Perl Monks concerning the following question:

Hi monks

Im now doing XML conversion job from a plain text file which has been pre-edited for conversion convenience.

Im having the text file in which there are four types of lists are there.

they are numberedlist which is pre-edited with <nl>, unnumberedlist with <un>, titled numberedlist <tl> and unnumbered title list <utl>.

A part of my input file is like this:

<nl>
slkjslkjslkjslks
slkjslkjslkjslkjs
slkslkjslkjsl
<utl>lksjlkjslkjs
lskjslkjslkjs
slkjslkjslkjslkj
</utl>
<un>lkslskjlkjs
<nl>lksjlksj
lkjlkjl
</nl>
</un>
</nl>

[download]

This is just a single instance of the nesting in the file. there are so many occurences are there in such a way that any list tag may consist of any number of list tags inside in any order in it, even itself inside. The above input has to be converted as :

<list type="numbered">
<listitem>slkjslkjslkjslks</listitem>
<listitem>slkjslkjslkjslkjs</listitem>
<listitem>slkslkjslkjsl</listitem>
<listitem><list type="unnumeredtitle"><listitem>lksjlkjslkjs</listitem
+>
<listitem>lskjslkjslkjs</listitem>
<listitem>slkjslkjslkjslkj</listitem>
</list></listitem><listitem><list type="unnumbered"><listitem>lkslskjl
+kjs</listitem>
<listitem><list type="numbered"><listitem>lksjlksj</listitem>
<listitem>lkjlkjl</listitem>
</list></listitem>
</list></listitem>
</list>

[download]

How should i start convert this text file into valid XML file

My english is not that good.

Please Give ur suggestions.

Thanks in advance.

--Murugesan--

Replies are listed 'Best First'.
•Re: Recursive lists
by merlyn (Sage) on Mar 23, 2004 at 14:56 UTC
    Looks like a perfect job for Parse::RecDescent or its heir apparent, Perl6::Rules. Using today's technology, the PRD grammar would be something like: 
    stuff: nl_list | un_list | tl_list | utl_list | items
nl_list: m{<nl>} stuff m{</nl>} { "<list type='numbered'>$item{stuff}<
+/list>" }
... ditto for the other three lists
items: item(s) { join "", @{$item[1]} }
item: /\w+/ { "<listitem>$item[1]</listitem>" }

    [download]

    -- Randal L. Schwartz, Perl hacker
    Be sure to read my standard disclaimer if this is a reply.

[reply]
[d/l]
      I haven't seen hide nor heir of Perl6::Rules.

          -- Chip Salzenberg, Free-Floating Agent of Chaos

[reply]
[reply]

      Thank you very much for ur kind reply

      i am a beginer in perl. Frankly, I dont understand what u have written in the code here. Can u please explain me what u have written. If i do the coding without understanding what the coding is meant for, then i wont improve my perl knowledge.

      So please kindly help me to understand what the code actually meants

      Thanks in advance

      --Murugesan--

[reply]
        Parse::RecDescent is an example of a grammar-based parser. You will need to understand something about grammars before you can understand it. I would suggest going to CPAN (www.cpan.org) and reading the extensive documentation provided with Parser::RecDescent before going much further.

        ------
        We are the carpenters and bricklayers of the Information Age.

        Then there are Damian modules.... *sigh* ... that's not about being less-lazy -- that's about being on some really good drugs -- you know, there is no spoon. - flyingmoose

[reply]

        merlin has given you an example grammar, and specifically stated that he was doing so. To understand the code, you are going to need to study the code and Perl6::Rules, as he stated.

[reply]

Back to Seekers of Perl Wisdom