From 201b9ef3e07ed5948730079475f79703b0cd28f8 Mon Sep 17 00:00:00 2001 From: Scott Worley Date: Mon, 19 Aug 2024 01:38:40 -0700 Subject: [PATCH 1/1] Proper log parsing I'm bummed that this couldn't be a simple Iterator::scan(). Scan doesn't have a way to get control one last time at end-of-stream to dump the accumulator state. --- src/lib.rs | 92 +++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 84 insertions(+), 8 deletions(-) diff --git a/src/lib.rs b/src/lib.rs index 1d098b0..b583c3e 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -9,12 +9,49 @@ struct RowInput { entries: Vec, } +struct Reader>> { + input: Input, + row: Option, +} +impl>> Reader { + #[cfg(test)] + fn new(input: Input) -> Self { + Self { input, row: None } + } +} +impl>> Iterator for Reader { + type Item = Result; + fn next(&mut self) -> Option { + loop { + match self.input.next() { + None => return Ok(std::mem::take(&mut self.row)).transpose(), + Some(Err(e)) => return Some(Err(e)), + Some(Ok(line)) if line.is_empty() && self.row.is_some() => { + return Ok(std::mem::take(&mut self.row)).transpose() + } + Some(Ok(line)) if line.is_empty() => {} + Some(Ok(line)) if line.starts_with(' ') => match &mut self.row { + None => return Some(Err(std::io::Error::other("Entry with no header"))), + Some(ref mut row) => row.entries.push(String::from(line.trim())), + }, + Some(Ok(line)) => { + let prev = std::mem::take(&mut self.row); + self.row = Some(RowInput { + label: line, + entries: vec![], + }); + if prev.is_some() { + return Ok(prev).transpose(); + } + } + } + } + } +} + #[cfg(test)] -fn read_rows(input: impl std::io::Read) -> impl Iterator { - std::io::BufReader::new(input).lines().map(|line| RowInput { - label: line.unwrap(), - entries: vec![], - }) +fn read_rows(input: impl std::io::Read) -> impl Iterator> { + Reader::new(std::io::BufReader::new(input).lines()) } pub fn tablify(_input: &impl std::io::Read) -> String { @@ -28,21 +65,21 @@ mod tests { #[test] fn test_read_rows() { assert_eq!( - read_rows(&b"foo"[..]).collect::>(), + read_rows(&b"foo"[..]).flatten().collect::>(), vec![RowInput { label: String::from("foo"), entries: vec![] }] ); assert_eq!( - read_rows(&b"bar"[..]).collect::>(), + read_rows(&b"bar"[..]).flatten().collect::>(), vec![RowInput { label: String::from("bar"), entries: vec![] }] ); assert_eq!( - read_rows(&b"foo\nbar\n"[..]).collect::>(), + read_rows(&b"foo\nbar\n"[..]).flatten().collect::>(), vec![ RowInput { label: String::from("foo"), @@ -54,5 +91,44 @@ mod tests { } ] ); + assert_eq!( + read_rows(&b"foo\n bar\n"[..]).flatten().collect::>(), + vec![RowInput { + label: String::from("foo"), + entries: vec![String::from("bar")] + }] + ); + assert_eq!( + read_rows(&b"foo\n bar\n baz\n"[..]) + .flatten() + .collect::>(), + vec![RowInput { + label: String::from("foo"), + entries: vec![String::from("bar"), String::from("baz")] + }] + ); + assert_eq!( + read_rows(&b"foo\n\nbar\n"[..]) + .flatten() + .collect::>(), + vec![ + RowInput { + label: String::from("foo"), + entries: vec![] + }, + RowInput { + label: String::from("bar"), + entries: vec![] + } + ] + ); + + let bad = read_rows(&b" foo"[..]).next().unwrap(); + assert!(bad.is_err()); + assert!(format!("{bad:?}").contains("Entry with no header")); + + let bad2 = read_rows(&b"foo\n\n bar"[..]).nth(1).unwrap(); + assert!(bad2.is_err()); + assert!(format!("{bad2:?}").contains("Entry with no header")); } } -- 2.44.1