return error result from fallible iteration methods #13
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| match self.get(Some(key.as_ref()), None, ffi::MDB_SET_RANGE) { | ||
| Ok(_) | Err(Error::NotFound) => (), | ||
| Err(error) => panic!("mdb_cursor_get returned an unexpected error: {}", error), | ||
| Err(error) => return Err(error), |
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Is this just e => e? Or is there a hidden conversion happening between Result errors?
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Generally, I'm fine with this approach, since it's both clear and minimizes dependencies. However, I'd like to make sure you're aware of https://github.com/sfackler/rust-fallible-iterator, which brings a little more machinery to the party.
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| assert_eq!(0, cursor.iter_dup_of(b"foo").count()); | ||
| assert_eq!(0, cursor.iter_dup_of(b"foo").unwrap().count()); |
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For next time: generally I like .expect("...") in tests, since it can help narrow down what really broke. This is especially useful when you have two .unwrap() invocations on a single line (which you do).
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Roger that. In this case, The changes are maintaining consistency with the existing code, which uses unwrap() everywhere.
src/cursor.rs
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| @@ -571,10 +584,30 @@ mod test { | |||
| let mut i = 0; | |||
| let mut count = 0u32; | |||
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| for (key, data) in cursor.iter().map(|x| x.unwrap()) { | |||
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Meh; these little lambda functions are pretty idiomatic.
src/cursor.rs
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| @@ -602,10 +602,6 @@ mod test { | |||
| let mut i = 0; | |||
| let mut count = 0u32; | |||
| for result in cursor.iter() { | |||
| // let (key, data) = match result { | |||
Thanks, that's good to know. If I understand correctly, |
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Since #14 subsumes this PR (includes these changes), and you seemed optimistic about that one (after some changes) when we discussed it, I'll close this PR in favor of that one. |
This branch implements the suggestion in danburkert#42 by returning an error result from fallible iteration methods (
Cursor.iter*()andIterator.next()) when those methods fail. See that issue for more info about the changes.(I've previously requested integration of these changes upstream in danburkert#44 and would like to move forward with these changes downstream while awaiting that integration.)