class Rouge::Guessers::GlobMapping

def self.by_pairs(mapping, filename)
  glob_map = {}
  mapping.each do |(glob, lexer_name)|
    lexer = Lexer.find(lexer_name)
    # ignore unknown lexers
    next unless lexer
    glob_map[lexer.name] ||= []
    glob_map[lexer.name] << glob
  end
  new(glob_map, filename)
end