Add hex_file_path_pattern(). Retrieves file paths based on a regex pattern.

This bit was added. Very useful for debugging.

/**
  * Returns an array of file paths based on a pattern.
  *
  * @see hex_file_path() for more info.
  *
  * @param $pattern
  *  A regex pattern that will be compared to each namespace for a given
  *  $scope.
  * @param $scope
  *  Can be 'all', 'theme' or 'plugin'. It can also be a specific theme or
  *  plug-in name, whichever owns or "hosts" the file. File discovery depends
  *  on how the scope was defined from the .info/.pinfo file. When this
  *  function is called, it can be any sub-set of the defined scope. It can
  *  also be a super-set but the returned file paths will always be limited by
  *  the scope set from .info/.pinfo.
 */
function hex_file_path_pattern($pattern, $scope = 'all') {
  $files = hex_cache('files')->data;
  $list  = array();
  if (isset($files[$scope])) {
    foreach (preg_grep($pattern, array_keys($files[$scope])) as $namespace) {
      $list = array_merge($list, $files[$scope][$namespace]);
    }
  }
  return $list;
}

This .info entry will produce an internal list of all files matching this extension and assign it to the "styles" name space:

file.extensions[styles] = .css

Example calls:

// Must pass a valid regex pattern.
$all_styles = hex_file_path_pattern(":styles:");

// Will output:
array(
  0 => string 'sites/all/themes/THEME/colors.css',
  1 => string 'sites/all/themes/THEME/layout.css',
  2 => string 'sites/all/themes/THEME/layout-rtl.css',
  3 => string 'sites/all/themes/THEME/override/foo.css',
  4 => string 'sites/all/themes/THEME/override/foo-rtl.css',
  5 => string 'sites/all/themes/THEME/override/bar.css',
  6 => string 'sites/all/themes/THEME/override/bar-rtl.css',
  //etc...
);

$rtl_styles = hex_file_path_pattern(":styles/.+-rtl:");

// Will output:
array(
  1 => string 'sites/all/themes/THEME/layout-rtl.css',
  2 => string 'sites/all/themes/THEME/override/foo-rtl.css',
  3 => string 'sites/all/themes/THEME/override/bar-rtl.css',
  //etc...
);

It can be used in a finished theme but most calls should be done through hex_file_path() and hex_file_path_multiple().