git.scottworley.com Git - tablify/blob - src/lib.rs

   1 use std::collections::{HashMap, HashSet};
   2 use std::io::BufRead;
   3 use std::iter::Iterator;
   4
   5 const HEADER: &str = "<!DOCTYPE html>
   6 <html>
   7 <head>
   8   <meta charset=\"utf-8\">
   9   <meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">
  10   <style>
  11     /* h/t https://wabain.github.io/2019/10/13/css-rotated-table-header.html */
  12     th, td { white-space: nowrap; }
  13     th { text-align: left; font-weight: normal; }
  14     table { border-collapse: collapse }
  15     tr.key > th { height: 8em; vertical-align: bottom; line-height: 1 }
  16     tr.key > th > div { width: 1em; }
  17     tr.key > th > div > div { width: 5em; transform-origin: bottom left; transform: translateX(1em) rotate(-65deg) }
  18     td { border: thin solid gray; }
  19     td.numeric { text-align: right; }
  20     td.yes { border: thin solid gray; background-color: gray; }
  21     td.spacer { border: none; }
  22     /* h/t https://stackoverflow.com/questions/5687035/css-bolding-some-text-without-changing-its-containers-size/46452396#46452396 */
  23     .highlight { text-shadow: -0.06ex 0 black, 0.06ex 0 black; }
  24     img { height: 1.2em; }
  25   </style>
  26   <script>
  27     function highlight(id)       { const e = document.getElementById(id); if (e) { e.classList.add(   \"highlight\"); } }
  28     function clear_highlight(id) { const e = document.getElementById(id); if (e) { e.classList.remove(\"highlight\"); } }
  29     function h2(a, b)  {       highlight(a);       highlight(b); }
  30     function ch2(a, b) { clear_highlight(a); clear_highlight(b); }
  31   </script>
  32 </head>
  33 <body>
  34   <table>
  35     <tbody>";
  36 const FOOTER: &str = "    </tbody>
  37   </table>
  38 </body>
  39 </html>";
  40
  41 #[derive(Debug, PartialEq, Eq, Hash)]
  42 struct Entry {
  43     col: String,
  44     instance: String,
  45 }
  46 impl From<&str> for Entry {
  47     fn from(value: &str) -> Entry {
  48         Entry {
  49             col: String::from(value),
  50             instance: String::from(""),
  51         }
  52     }
  53 }
  54
  55 #[derive(Debug, PartialEq, Eq)]
  56 struct RowInput {
  57     label: String,
  58     entries: Vec<Entry>,
  59 }
  60
  61 struct Reader<Input: Iterator<Item = Result<String, std::io::Error>>> {
  62     input: std::iter::Enumerate<Input>,
  63     row: Option<RowInput>,
  64 }
  65 impl<Input: Iterator<Item = Result<String, std::io::Error>>> Reader<Input> {
  66     fn new(input: Input) -> Self {
  67         Self {
  68             input: input.enumerate(),
  69             row: None,
  70         }
  71     }
  72 }
  73 impl<Input: Iterator<Item = Result<String, std::io::Error>>> Iterator for Reader<Input> {
  74     type Item = Result<RowInput, std::io::Error>;
  75     fn next(&mut self) -> Option<Self::Item> {
  76         loop {
  77             match self
  78                 .input
  79                 .next()
  80                 .map(|(n, r)| (n, r.map(|line| String::from(line.trim_end()))))
  81             {
  82                 None => return Ok(std::mem::take(&mut self.row)).transpose(),
  83                 Some((_, Err(e))) => return Some(Err(e)),
  84                 Some((_, Ok(line))) if line.is_empty() && self.row.is_some() => {
  85                     return Ok(std::mem::take(&mut self.row)).transpose()
  86                 }
  87                 Some((_, Ok(line))) if line.is_empty() => {}
  88                 Some((n, Ok(line))) if line.starts_with(' ') => match &mut self.row {
  89                     None => {
  90                         return Some(Err(std::io::Error::other(format!(
  91                             "{}: Entry with no header",
  92                             n + 1
  93                         ))))
  94                     }
  95                     Some(ref mut row) => row.entries.push(Entry::from(line.trim())),
  96                 },
  97                 Some((_, Ok(line))) => {
  98                     let prev = std::mem::take(&mut self.row);
  99                     self.row = Some(RowInput {
 100                         label: line,
 101                         entries: vec![],
 102                     });
 103                     if prev.is_some() {
 104                         return Ok(prev).transpose();
 105                     }
 106                 }
 107             }
 108         }
 109     }
 110 }
 111
 112 fn read_rows(input: impl std::io::Read) -> impl Iterator<Item = Result<RowInput, std::io::Error>> {
 113     Reader::new(std::io::BufReader::new(input).lines())
 114 }
 115
 116 fn column_counts(rows: &[RowInput]) -> Vec<(usize, String)> {
 117     let mut counts: Vec<_> = rows
 118         .iter()
 119         .flat_map(|r| r.entries.iter().collect::<HashSet<_>>().into_iter())
 120         .fold(HashMap::new(), |mut cs, e| {
 121             cs.entry(String::from(&e.col))
 122                 .and_modify(|n| *n += 1)
 123                 .or_insert(1);
 124             cs
 125         })
 126         .into_iter()
 127         .map(|(col, n)| (n, col))
 128         .collect();
 129     counts.sort();
 130     counts
 131 }
 132
 133 /// # Errors
 134 ///
 135 /// Will return `Err` if
 136 ///   * there's an i/o error while reading `input`
 137 ///   * the log has invalid syntax:
 138 ///     * an indented line with no preceding non-indented line
 139 pub fn tablify(input: impl std::io::Read) -> Result<String, std::io::Error> {
 140     let rows = read_rows(input).collect::<Result<Vec<_>, _>>()?;
 141     let _columns = column_counts(&rows);
 142     Ok(String::from(HEADER) + "Hello, world!" + FOOTER)
 143 }
 144
 145 #[cfg(test)]
 146 mod tests {
 147     use super::*;
 148
 149     #[test]
 150     fn test_read_rows() {
 151         assert_eq!(
 152             read_rows(&b"foo"[..]).flatten().collect::<Vec<_>>(),
 153             vec![RowInput {
 154                 label: String::from("foo"),
 155                 entries: vec![]
 156             }]
 157         );
 158         assert_eq!(
 159             read_rows(&b"bar"[..]).flatten().collect::<Vec<_>>(),
 160             vec![RowInput {
 161                 label: String::from("bar"),
 162                 entries: vec![]
 163             }]
 164         );
 165         assert_eq!(
 166             read_rows(&b"foo\nbar\n"[..]).flatten().collect::<Vec<_>>(),
 167             vec![
 168                 RowInput {
 169                     label: String::from("foo"),
 170                     entries: vec![]
 171                 },
 172                 RowInput {
 173                     label: String::from("bar"),
 174                     entries: vec![]
 175                 }
 176             ]
 177         );
 178         assert_eq!(
 179             read_rows(&b"foo\n bar\n"[..]).flatten().collect::<Vec<_>>(),
 180             vec![RowInput {
 181                 label: String::from("foo"),
 182                 entries: vec![Entry::from("bar")]
 183             }]
 184         );
 185         assert_eq!(
 186             read_rows(&b"foo\n bar\n baz\n"[..])
 187                 .flatten()
 188                 .collect::<Vec<_>>(),
 189             vec![RowInput {
 190                 label: String::from("foo"),
 191                 entries: vec![Entry::from("bar"), Entry::from("baz")]
 192             }]
 193         );
 194         assert_eq!(
 195             read_rows(&b"foo\n\nbar\n"[..])
 196                 .flatten()
 197                 .collect::<Vec<_>>(),
 198             vec![
 199                 RowInput {
 200                     label: String::from("foo"),
 201                     entries: vec![]
 202                 },
 203                 RowInput {
 204                     label: String::from("bar"),
 205                     entries: vec![]
 206                 }
 207             ]
 208         );
 209         assert_eq!(
 210             read_rows(&b"foo\n \nbar\n"[..])
 211                 .flatten()
 212                 .collect::<Vec<_>>(),
 213             vec![
 214                 RowInput {
 215                     label: String::from("foo"),
 216                     entries: vec![]
 217                 },
 218                 RowInput {
 219                     label: String::from("bar"),
 220                     entries: vec![]
 221                 }
 222             ]
 223         );
 224         assert_eq!(
 225             read_rows(&b"foo  \n bar  \n"[..])
 226                 .flatten()
 227                 .collect::<Vec<_>>(),
 228             vec![RowInput {
 229                 label: String::from("foo"),
 230                 entries: vec![Entry::from("bar")]
 231             }]
 232         );
 233
 234         let bad = read_rows(&b" foo"[..]).next().unwrap();
 235         assert!(bad.is_err());
 236         assert!(format!("{bad:?}").contains("1: Entry with no header"));
 237
 238         let bad2 = read_rows(&b"foo\n\n bar"[..]).nth(1).unwrap();
 239         assert!(bad2.is_err());
 240         assert!(format!("{bad2:?}").contains("3: Entry with no header"));
 241     }
 242
 243     #[test]
 244     fn test_column_counts() {
 245         assert_eq!(
 246             column_counts(
 247                 &read_rows(&b"foo\n bar\n baz\n"[..])
 248                     .collect::<Result<Vec<_>, _>>()
 249                     .unwrap()
 250             ),
 251             vec![(1, String::from("bar")), (1, String::from("baz"))]
 252         );
 253         assert_eq!(
 254             column_counts(
 255                 &read_rows(&b"foo\n bar\n baz\nquux\n baz"[..])
 256                     .collect::<Result<Vec<_>, _>>()
 257                     .unwrap()
 258             ),
 259             vec![(1, String::from("bar")), (2, String::from("baz"))]
 260         );
 261         assert_eq!(
 262             column_counts(
 263                 &read_rows(&b"foo\n bar\n bar\n baz\n bar\nquux\n baz"[..])
 264                     .collect::<Result<Vec<_>, _>>()
 265                     .unwrap()
 266             ),
 267             vec![(1, String::from("bar")), (2, String::from("baz"))]
 268         );
 269     }
 270 }