module Metanorma::Utils

def to_ncname(name, asciionly: false)

NCName is "an XML Name, minus the :"
It follows the requirements of the specification for NCName: https://www.w3.org/TR/xml-names/#NT-NCName

# => "1___2___3"
to_ncname('1 < 2 & 3')

A utility method for escaping XML NCNames (XML Names without colons). 
def to_ncname(name, asciionly: false)
  name, valid = to_ncname_prep(name, asciionly)
  valid and return name
  starting_char = name[0]
  starting_char.gsub!(INVALID_NCNAME_START_REGEXP, NCNAME_INVALID)
  name.size == 1 and return starting_char
  following_chars = name[1..-1]
  following_chars.gsub!(INVALID_NCNAME_CHAR_REGEXP, NCNAME_INVALID)
  following_chars.gsub!(":", NCNAME_INVALID)
  starting_char << following_chars
end