class<\/span> StateBuilder<\/span><\/div> def<\/span> initialize<\/span><\/div> @number_created<\/span><\/div> end<\/span><\/div> <\/div>
def<\/span> create_from<\/span>(<\/span>pattern_string<\/span>)<\/span><\/div> string_reader<\/span> =<\/span> StringReader<\/span>.<\/span>new<\/span>(<\/span>pattern_string<\/span>)<\/span><\/div> root<\/span> =<\/span> _create_start_state<\/span><\/div> current_state<\/span> =<\/span> root<\/span><\/div> <\/div>
string_reader<\/span>.<\/span>read_each<\/span> do<\/span> |<\/span>current_character<\/span>|<\/span><\/div> current_transition<\/span> =<\/span> create_transition<\/span>(<\/span>current_character<\/span>,<\/span> current_state<\/span>)<\/span><\/div> current_state<\/span>.<\/span>add_transition<\/span>(<\/span>current_transition<\/span>)<\/span><\/div> current_state<\/span> =<\/span> current_transition<\/span>.<\/span>destination<\/span><\/div> end<\/span><\/div> <\/div>
final_state<\/span> =<\/span> _create_terminal_state<\/span><\/div> final_transition<\/span> =<\/span> AlwaysTransition<\/span>.<\/span>new<\/span>(<\/span>final_state<\/span>,<\/span> nil<\/span>)<\/span><\/div> current_state<\/span>.<\/span>add_transition<\/span>(<\/span>final_transition<\/span>)<\/span><\/div> <\/div>
return<\/span> root<\/span><\/div> end<\/span><\/div> <\/div>
def<\/span> create_transition<\/span>(<\/span>match_token<\/span>,<\/span> previous_state<\/span>)<\/span><\/div> case<\/span> match_token<\/span><\/div> when<\/span> "."<\/span> then<\/span> MatchAnyTransition<\/span>.<\/span>new<\/span>(<\/span>_create_standard_state<\/span>,<\/span> match_token<\/span>)<\/span><\/div> when<\/span> "*"<\/span> then<\/span> MatchAnyTransition<\/span>.<\/span>new<\/span>(<\/span>previous_state<\/span>,<\/span> match_token<\/span>)<\/span><\/div> else<\/span> LiteralTransition<\/span>.<\/span>new<\/span>(<\/span>_create_standard_state<\/span>,<\/span> match_token<\/span>)<\/span><\/div> end<\/span><\/div> end<\/span><\/div> <\/div>
def<\/span> _create_terminal_state<\/span><\/div> @number_created<\/span> +=<\/span> 1<\/span><\/div> result<\/span> =<\/span> TerminalState<\/span>.<\/span>new<\/span>(<\/span>@number_created<\/span>)<\/span><\/div> return<\/span> result<\/span><\/div> end<\/span><\/div> <\/div>
def<\/span> _create_start_state<\/span><\/div> @number_created<\/span> =<\/span> 0<\/span><\/div> result<\/span> =<\/span> StartState<\/span>.<\/span>new<\/span>(<\/span>@number_created<\/span>)<\/span><\/div> return<\/span> result<\/span><\/div> end<\/span><\/div> <\/div>
def<\/span> _create_standard_state<\/span><\/div> @number_created<\/span> +=<\/span> 1<\/span><\/div> result<\/span> =<\/span> StandardState<\/span>.<\/span>new<\/span>(<\/span>@number_created<\/span>)<\/span><\/div> return<\/span> result<\/span><\/div> end<\/span><\/div>end<\/span><\/div><\/pre><\/div>\n \n <\/div>\n\n