microdata.php

<?php

    // must already have cross-references resolved into a flat list
    // see $wiki_line in exdata
    function EncodeLine($line) {
        $dump = '';
        foreach ($line as $index => $row) {
            $dump .= ($index === 0)? "Item\n" : "Item $index\n";
            $dump .= "   Type: " . $row['type'];            
            foreach ($row as $key => $val) { $dump .= "   $key = $val\n"; }
        }
        return $dump;
    }





    // turns a tree encoding into a flat list
    // should turn $wiki_line into $wiki_deep
    function Linearize($tree, $base, $old_rewrite) {

        $output    = array();
        $stash     = array();
        $rewrite   = array();
        $base_ofs  = count($base);
        $stash_ofs = 0;
        $or_ofs    = count($old_rewrite);

        foreach ($tree as $index => $row) {
            $output[] = $row;
            $i        = 0;
            foreach ($row as $k => $v) {
                if (is_array($v)) {
                    $stash[]   = $v;
                    $rewrite[] = array('item' => $base_ofs + $i, 'k' => $k, 'si' => ($or_ofs + ($stash_ofs++));
                }
                ++$i;
            }
        }

        if (count($rewrite)) {
            Linearize($stash, array_merge($base, $output), array_merge($old_rewrite, $rewrite));
        } else {
            $res = array_merge($base, $output);
            foreach ($old_rewrite as $rule) {
                $res[$rule['item']][$rule['k']] = 'Item (' . $rule['si'] . ')';
            }
        }

    }

?>

see https://gist.github.com/StoneCypher/e33c3293dc5395c124b8 for source data