code: function determinePartialName(partial_path, source_path, options) {
    var match, rel, abs,
      path_reg = /(\.\.?\/)?(.+)/;
  
    // use a regex to find whether or not this is a relative path  
    match = path_reg.exec(partial_path);
    if (match[1]) {
      // use os-appropriate separator
      rel = partial_path.replace('/', path.sep);
  
      // join the root, the source_path, and the relative path, then find the relative path from the root
      // this is the new "absolute"" path
      abs = path.relative(options.root, path.join(options.root, source_path, rel));
    } else {
      // use os-appropriate separator
      abs = match[2].replace('/', path.sep);
    }
  
    // now use the naming function to get the name
    return options.namingFn(abs, options);
  }
docs: Figure out the name for a dust dependency