# File lib/amalgalite/database.rb, line 702
    def define_function( name, callable = nil, &block ) 
      p = ( callable || block ).to_proc
      raise FunctionError, "Use only mandatory or arbitrary parameters in an SQL Function, not both" if p.arity < -1
      db_function = ::Amalgalite::SQLite3::Database::Function.new( name, p )
      @api.define_function( db_function.name, db_function )
      @functions[db_function.signature] = db_function
      nil
    end