class Asciidoctor::PathResolver

def absolute_path? path

returns a Boolean indicating whether the path is an absolute root path

path - the String path to check

backslash. Windows roots can start with a drive letter.
Unix absolute paths start with a slash. UNC paths can start with a slash or

not have to be posixified beforehand. This operation does not handle URIs.
This operation considers both posix paths and Windows paths. The path does

Public: Check whether the specified path is an absolute path. 
def absolute_path? path
  (path.start_with? SLASH) || (@file_separator == BACKSLASH && (WindowsRootRx.match? path))
end