* [Caml-list] undo_input_line @ 2002-08-08 7:14 Oleg 2002-08-09 12:45 ` Xavier Leroy 0 siblings, 1 reply; 2+ messages in thread From: Oleg @ 2002-08-08 7:14 UTC (permalink / raw) To: caml-list Hi Does `let s = input_line ic` always increment `pos_in ic` by `String.length s + 1` ? So, if I define a function let undo_input_line ic s = seek_in ic (pos_in ic - String.length s - 1);; will it always work as expected, or will this depend on I/O mode (binary vs text) and file format (DOS vs UNIX)? Thanks Oleg ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners ^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [Caml-list] undo_input_line 2002-08-08 7:14 [Caml-list] undo_input_line Oleg @ 2002-08-09 12:45 ` Xavier Leroy 0 siblings, 0 replies; 2+ messages in thread From: Xavier Leroy @ 2002-08-09 12:45 UTC (permalink / raw) To: Oleg; +Cc: caml-list > Does `let s = input_line ic` always increment `pos_in ic` by > `String.length s + 1` ? Only if "ic" is in binary mode. In text mode, conversions may happen during reading (e.g. under Windows, removal of the final \r) that invalidate this claim. > So, if I define a function > let undo_input_line ic s = > seek_in ic (pos_in ic - String.length s - 1);; > will it always work as expected, or will this depend on I/O mode (binary vs > text) and file format (DOS vs UNIX)? To "undo" an input, I'd recommend doing "let p = pos_in ic" before the read, performing the read, and doing "seek_in ic p" to undo the read. This will be a lot more robust. - Xavier Leroy ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners ^ permalink raw reply [flat|nested] 2+ messages in thread
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