ggorlen/markov.php

## markov.php
<?php
  if (isset($_GET['source'])) {
    highlight_file($_SERVER['SCRIPT_FILENAME']);
    exit;
  }
?>

<!DOCTYPE html>
<html lang="en">
  <head>
    <title>Markov generator</title>
    <style>
      body, input {
        font-family: monospace, 'lucida console', 'courier new';
        font-size: 13px;
      }
      .main {
        margin-top: 10px;
        margin-left: auto;
        margin-right: auto;
        width: 500px;
        padding: 10px;
      }
      form table td {
        padding: 5px;
      }
      textarea {
        width: 100%;
        height: 150px;
      }
    </style>
  </head>
  <body>
    <h2 style='text-align: center;'>Markov generator</h2>
    <div class='main'>
      <form name='markovinput' method='POST' action='markov.php' onreset='clearText();'>
        <table style="width: 100%;">
          <tr>
            <td>
              Source:<br>
              <textarea autofocus required id='inputtextarea' name='text'><?php
                if (!count($_POST) || !isset($_POST['text'])) {

                  // load file
                  $kafkaFile = fopen('pg5200.txt', 'r') or die('File error');
                  $kafka = fread($kafkaFile, filesize('pg5200.txt'));
                  fclose($kafkaFile);
                  // split on whitespace
                  $kafka = preg_split('/\s+/', $kafka);

                  // disregard headers and footers
                  $kafka = array_slice($kafka, 126, -2974);
                  print implode(' ', $kafka);
                }
                else if (isset($_POST['text'])) {
                  print $_POST['text'];
                }
              ?></textarea>
            </td>
          </tr>
        </table>
        <table>
          <tr>
            <td>
              Order:<br>
              <input size=4 name='order' value=2>
            </td>
            <td>
              Output length in words:<br>
              <input size=8 name='size' value=2000>
            </td>
          </tr>
          <tr>
            <td>
              <input type='submit'>&nbsp;<input type='reset'>
            </td>
          </tr>
          <tr>
            <td>
              <a href='../'>Return home</a>
            </td>
          </tr>
        </table>
      </form>
      <hr>
    </div>
    <div class='main'>
      <?php
         (function() {
          /* Markov generator
           *
           * resources:
           * http://stackoverflow.com/questions/4081662/explain-markov-chain-algorithm-in-laymans-terms
           * http://vivin.net/projects/sulekha/
           * https://blog.codinghorror.com/markov-and-you/
           * http://greenteapress.com/thinkpython/html/thinkpython014.html
           *
           */
          // get user input
          if (count($_POST) && isset($_POST['order']) &&
              isset($_POST['text']) && isset($_POST['size'])) {
            $order = $_POST['order'];
            $size = $_POST['size'];
            $text = $_POST['text'];
          }
          else { return; }
          // split on whitespace
          $text = preg_split('/\s+/', $text);

          // validate input
          if ($order >= count($text)) {
            print "Order must be smaller than the number
                   of words in the source text.";
            return;
          }

          // create a map to hold the analysis
          $map = [];
          // map prefixes to suffixes
          for ($i = 0; $i < count($text) - $order; $i++) {
            $prefix = [];
            for ($j = 0; $j < $order; $j++) {
              array_push($prefix, $text[$i + $j]);
            }
            // append suffix or add new prefix to the map
            $prefix = implode(' ', $prefix);
            if (array_key_exists($prefix, $map)) {
              array_push($map[$prefix], $text[$i + $j]);
            }
            else {
              $map[$prefix] = [$text[$i + $j]];
            }
          }
          // grab a random prefix from the map to start with
          $keys = array_keys($map);
          $prefix = $keys[array_rand($keys)];
          for ($i = 0; $i < $size; $i++) {
            // retrieve list of suffixes for this prefix or try another
            while (!array_key_exists($prefix, $map)) {
              $prefix = $keys[array_rand($keys)];
            }
            $temp = $map[$prefix];

            // pick a random suffix that follows this prefix and print
            $suffix = $temp[array_rand($temp)];
            print $suffix . ' ';

            // create a new prefix by appending the suffix to
            // the prefix and dropping the first word
            $prefixArr = explode(' ', $prefix);
            $prefix = implode(' ', array_slice($prefixArr, 1)) . ' ' . $suffix;
          }
        })();
      ?>
    </div>
    <script>
      function clearText() {
        document.getElementById('inputtextarea').innerHTML = '';
      }
      <?php
        if (isset($_POST['size'])) {
          print "document.forms['markovinput'].elements['size'].value = " .
                $_POST['size'] . ";\n";
        }
        if (isset($_POST['order'])) {
          print "document.forms['markovinput'].elements['order'].value = " .
                $_POST['order'] . ";\n";
        }
      ?>
    </script>
  </body>
</html>
	<?php
	if (isset($_GET['source'])) {
	highlight_file($_SERVER['SCRIPT_FILENAME']);
	exit;
	}
	?>

	<!DOCTYPE html>
	<html lang="en">
	<head>
	<title>Markov generator</title>
	<style>
	body, input {
	font-family: monospace, 'lucida console', 'courier new';
	font-size: 13px;
	}
	.main {
	margin-top: 10px;
	margin-left: auto;
	margin-right: auto;
	width: 500px;
	padding: 10px;
	}
	form table td {
	padding: 5px;
	}
	textarea {
	width: 100%;
	height: 150px;
	}
	</style>
	</head>
	<body>
	<h2 style='text-align: center;'>Markov generator</h2>
	<div class='main'>
	<form name='markovinput' method='POST' action='markov.php' onreset='clearText();'>
	<table style="width: 100%;">
	<tr>
	<td>
	Source:<br>
	<textarea autofocus required id='inputtextarea' name='text'><?php
	if (!count($_POST) \|\| !isset($_POST['text'])) {

	// load file
	$kafkaFile = fopen('pg5200.txt', 'r') or die('File error');
	$kafka = fread($kafkaFile, filesize('pg5200.txt'));
	fclose($kafkaFile);
	// split on whitespace
	$kafka = preg_split('/\s+/', $kafka);

	// disregard headers and footers
	$kafka = array_slice($kafka, 126, -2974);
	print implode(' ', $kafka);
	}
	else if (isset($_POST['text'])) {
	print $_POST['text'];
	}
	?></textarea>
	</td>
	</tr>
	</table>
	<table>
	<tr>
	<td>
	Order:<br>
	<input size=4 name='order' value=2>
	</td>
	<td>
	Output length in words:<br>
	<input size=8 name='size' value=2000>
	</td>
	</tr>
	<tr>
	<td>
	<input type='submit'> <input type='reset'>
	</td>
	</tr>
	<tr>
	<td>
	<a href='../'>Return home</a>
	</td>
	</tr>
	</table>
	</form>
	<hr>
	</div>
	<div class='main'>
	<?php
	(function() {
	/* Markov generator
	*
	* resources:
	* http://stackoverflow.com/questions/4081662/explain-markov-chain-algorithm-in-laymans-terms
	* http://vivin.net/projects/sulekha/
	* https://blog.codinghorror.com/markov-and-you/
	* http://greenteapress.com/thinkpython/html/thinkpython014.html
	*
	*/
	// get user input
	if (count($_POST) && isset($_POST['order']) &&
	isset($_POST['text']) && isset($_POST['size'])) {
	$order = $_POST['order'];
	$size = $_POST['size'];
	$text = $_POST['text'];
	}
	else { return; }
	// split on whitespace
	$text = preg_split('/\s+/', $text);

	// validate input
	if ($order >= count($text)) {
	print "Order must be smaller than the number
	of words in the source text.";
	return;
	}

	// create a map to hold the analysis
	$map = [];
	// map prefixes to suffixes
	for ($i = 0; $i < count($text) - $order; $i++) {
	$prefix = [];
	for ($j = 0; $j < $order; $j++) {
	array_push($prefix, $text[$i + $j]);
	}
	// append suffix or add new prefix to the map
	$prefix = implode(' ', $prefix);
	if (array_key_exists($prefix, $map)) {
	array_push($map[$prefix], $text[$i + $j]);
	}
	else {
	$map[$prefix] = [$text[$i + $j]];
	}
	}
	// grab a random prefix from the map to start with
	$keys = array_keys($map);
	$prefix = $keys[array_rand($keys)];
	for ($i = 0; $i < $size; $i++) {
	// retrieve list of suffixes for this prefix or try another
	while (!array_key_exists($prefix, $map)) {
	$prefix = $keys[array_rand($keys)];
	}
	$temp = $map[$prefix];

	// pick a random suffix that follows this prefix and print
	$suffix = $temp[array_rand($temp)];
	print $suffix . ' ';

	// create a new prefix by appending the suffix to
	// the prefix and dropping the first word
	$prefixArr = explode(' ', $prefix);
	$prefix = implode(' ', array_slice($prefixArr, 1)) . ' ' . $suffix;
	}
	})();
	?>
	</div>
	<script>
	function clearText() {
	document.getElementById('inputtextarea').innerHTML = '';
	}
	<?php
	if (isset($_POST['size'])) {
	print "document.forms['markovinput'].elements['size'].value = " .
	$_POST['size'] . ";\n";
	}
	if (isset($_POST['order'])) {
	print "document.forms['markovinput'].elements['order'].value = " .
	$_POST['order'] . ";\n";
	}
	?>
	</script>
	</body>
	</html>