Re: Style guide / optimisation...

[Daniel Diaz]

Hi You are right =.. is not very efficient. You can use call/2-N to avoid this http://www.gprolog.org/manual/html_node/gprolog042.html#sec194 Also the reverse is time and space consuming. This is strange because you use an accumulator: this is generally used to avoid append or reverse. In fact the accumulator is not needed and avoids the use of reverse. Here is the resulting version: file_codes(From, Out) :-     open(From, read, S),     file_read_buf(S, get_code, -1, Out),     close(S). file_chars(From, Out) :-     open(From, read, S),     file_read_buf(S, get_char, end_of_file, Out),     close(S). file_read_buf(S, Fetcher, Eof, Out) :-     call(Fetcher, S, Chr),     (   Chr \== Eof ->         Out = [Chr|Out1],         file_read_buf(S, Fetcher, Eof, Out1)     ;         Out = []     ). Daniel Le 14/10/2014 00:42, emacstheviking a écrit : file_codes(From, Out) :- open(From, read, S), file_read_buf(S, [], get_code, -1, Out), close(S). file_chars(From, Out) :- open(From, read, S), file_read_buf(S, [], get_char, end_of_file, Out), close(S). file_read_buf(S, Acc, Fetcher, Eof, Out) :- Reader =.. [Fetcher, S, Chr], call(Reader), ( Chr == Eof -> reverse(Acc, Out) ; file_read_buf(S, [Chr|Acc], Fetcher, Eof, Out)). I wanted to avoid using =.. every time I read another bit of the file; it just feels like it should be outside the loop, I tried this but it didn't do what I expected:     file_read_buf(S, [], get_code(S, _Chr), -1, Out) So, how can I make this more efficient and prolog-gy? -- Ce message a été vérifié par MailScanner pour des virus ou des polluriels et rien de suspect n'a été trouvé.

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