Creating a custom parser

joshlk

To make it a lot easer for myself when writing long documents, how is it possible to create a parser as such to convert my own mark-up language into html? So php would open a text file and would convert "==" to “<h2> and then the ending "==" into "</h2>", then outputting the html. Also depending on the amount of “=” would describe the heading level, so “===” would be “<h3>” and so on. Also "#{comment}" to "<div class="comment">" and the ending # into "</div>". Is such a thing possible?

NogDog

It's certainly possible (though questionable to me as to whether it's worth the effort 🙂 ). You could use preg_replace() with coordinated arrays for the first two arguments:

$search = array(
  '/===={([^}]*)}(.*)====/s',
  '/====(.*)====/s',
  '/==={([^}]*)}(.*)===/s',
  '/===(.*)===/s',
  '/=={([^}]*)}(.*)==/s',
  '/==(.*)==/s',
  '/(?<!class)={([^}]*)}(.*)=/s',
  '/(?<!class)=(.*)=/s'
);
$replace = array(
  '<h4 class="\\1">\\2</h4>',
  '<h4>\\1</h4>',
  '<h3 class="\\1">\\2</h3>',
  '<h3>\\1</h3>',
  '<h2 class="\\1">\\2</h2>',
  '<h2>\\1</h2>',
  '<div class="\\1">\\2</div>',
  '<div>\\1</div>'
);
echo(preg_replace($search, $replace, $string));

joshlk

Is it posible to tell me how this code works?

NogDog

joshlk wrote:
Is it posible to tell me how this code works?

I don't think I have time to do that much typing, but I can point you to:
preg_replace() function
PCRE regex syntax
PCRE regex modifiers