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: Option<String>,
  45 }
  46 impl From<&str> for Entry {
  47     fn from(value: &str) -> Entry {
  48         match value.split_once(':') {
  49             None => Entry {
  50                 col: String::from(value),
  51                 instance: None,
  52             },
  53             Some((col, instance)) => Entry {
  54                 col: String::from(col.trim()),
  55                 instance: Some(String::from(instance.trim())),
  56             },
  57         }
  58     }
  59 }
  60
  61 #[derive(Debug, PartialEq, Eq)]
  62 struct RowInput {
  63     label: String,
  64     entries: Vec<Entry>,
  65 }
  66
  67 struct Reader<Input: Iterator<Item = Result<String, std::io::Error>>> {
  68     input: std::iter::Enumerate<Input>,
  69     row: Option<RowInput>,
  70 }
  71 impl<Input: Iterator<Item = Result<String, std::io::Error>>> Reader<Input> {
  72     fn new(input: Input) -> Self {
  73         Self {
  74             input: input.enumerate(),
  75             row: None,
  76         }
  77     }
  78 }
  79 impl<Input: Iterator<Item = Result<String, std::io::Error>>> Iterator for Reader<Input> {
  80     type Item = Result<RowInput, std::io::Error>;
  81     fn next(&mut self) -> Option<Self::Item> {
  82         loop {
  83             match self
  84                 .input
  85                 .next()
  86                 .map(|(n, r)| (n, r.map(|line| String::from(line.trim_end()))))
  87             {
  88                 None => return Ok(std::mem::take(&mut self.row)).transpose(),
  89                 Some((_, Err(e))) => return Some(Err(e)),
  90                 Some((_, Ok(line))) if line.is_empty() && self.row.is_some() => {
  91                     return Ok(std::mem::take(&mut self.row)).transpose()
  92                 }
  93                 Some((_, Ok(line))) if line.is_empty() => {}
  94                 Some((n, Ok(line))) if line.starts_with(' ') => match &mut self.row {
  95                     None => {
  96                         return Some(Err(std::io::Error::other(format!(
  97                             "{}: Entry with no header",
  98                             n + 1
  99                         ))))
 100                     }
 101                     Some(ref mut row) => row.entries.push(Entry::from(line.trim())),
 102                 },
 103                 Some((_, Ok(line))) => {
 104                     let prev = std::mem::take(&mut self.row);
 105                     self.row = Some(RowInput {
 106                         label: line,
 107                         entries: vec![],
 108                     });
 109                     if prev.is_some() {
 110                         return Ok(prev).transpose();
 111                     }
 112                 }
 113             }
 114         }
 115     }
 116 }
 117
 118 fn read_rows(input: impl std::io::Read) -> impl Iterator<Item = Result<RowInput, std::io::Error>> {
 119     Reader::new(std::io::BufReader::new(input).lines())
 120 }
 121
 122 fn column_counts(rows: &[RowInput]) -> Vec<(usize, String)> {
 123     let mut counts: Vec<_> = rows
 124         .iter()
 125         .flat_map(|r| {
 126             r.entries
 127                 .iter()
 128                 .map(|e| &e.col)
 129                 .collect::<HashSet<_>>()
 130                 .into_iter()
 131         })
 132         .fold(HashMap::new(), |mut cs, col| {
 133             cs.entry(String::from(col))
 134                 .and_modify(|n| *n += 1)
 135                 .or_insert(1);
 136             cs
 137         })
 138         .into_iter()
 139         .map(|(col, n)| (n, col))
 140         .collect();
 141     counts.sort();
 142     counts
 143 }
 144 fn column_order(rows: &[RowInput]) -> Vec<String> {
 145     column_counts(rows)
 146         .into_iter()
 147         .map(|(_, col)| col)
 148         .collect()
 149 }
 150
 151 /// # Errors
 152 ///
 153 /// Will return `Err` if
 154 ///   * there's an i/o error while reading `input`
 155 ///   * the log has invalid syntax:
 156 ///     * an indented line with no preceding non-indented line
 157 pub fn tablify(input: impl std::io::Read) -> Result<String, std::io::Error> {
 158     let rows = read_rows(input).collect::<Result<Vec<_>, _>>()?;
 159     let _columns = column_order(&rows);
 160     Ok(String::from(HEADER) + "Hello, world!" + FOOTER)
 161 }
 162
 163 #[cfg(test)]
 164 mod tests {
 165     use super::*;
 166
 167     #[test]
 168     fn test_parse_entry() {
 169         assert_eq!(
 170             Entry::from("foo"),
 171             Entry {
 172                 col: String::from("foo"),
 173                 instance: None
 174             }
 175         );
 176         assert_eq!(
 177             Entry::from("foo:bar"),
 178             Entry {
 179                 col: String::from("foo"),
 180                 instance: Some(String::from("bar"))
 181             }
 182         );
 183         assert_eq!(
 184             Entry::from("foo: bar"),
 185             Entry {
 186                 col: String::from("foo"),
 187                 instance: Some(String::from("bar"))
 188             }
 189         );
 190     }
 191
 192     #[test]
 193     fn test_read_rows() {
 194         assert_eq!(
 195             read_rows(&b"foo"[..]).flatten().collect::<Vec<_>>(),
 196             vec![RowInput {
 197                 label: String::from("foo"),
 198                 entries: vec![]
 199             }]
 200         );
 201         assert_eq!(
 202             read_rows(&b"bar"[..]).flatten().collect::<Vec<_>>(),
 203             vec![RowInput {
 204                 label: String::from("bar"),
 205                 entries: vec![]
 206             }]
 207         );
 208         assert_eq!(
 209             read_rows(&b"foo\nbar\n"[..]).flatten().collect::<Vec<_>>(),
 210             vec![
 211                 RowInput {
 212                     label: String::from("foo"),
 213                     entries: vec![]
 214                 },
 215                 RowInput {
 216                     label: String::from("bar"),
 217                     entries: vec![]
 218                 }
 219             ]
 220         );
 221         assert_eq!(
 222             read_rows(&b"foo\n bar\n"[..]).flatten().collect::<Vec<_>>(),
 223             vec![RowInput {
 224                 label: String::from("foo"),
 225                 entries: vec![Entry::from("bar")]
 226             }]
 227         );
 228         assert_eq!(
 229             read_rows(&b"foo\n bar\n baz\n"[..])
 230                 .flatten()
 231                 .collect::<Vec<_>>(),
 232             vec![RowInput {
 233                 label: String::from("foo"),
 234                 entries: vec![Entry::from("bar"), Entry::from("baz")]
 235             }]
 236         );
 237         assert_eq!(
 238             read_rows(&b"foo\n\nbar\n"[..])
 239                 .flatten()
 240                 .collect::<Vec<_>>(),
 241             vec![
 242                 RowInput {
 243                     label: String::from("foo"),
 244                     entries: vec![]
 245                 },
 246                 RowInput {
 247                     label: String::from("bar"),
 248                     entries: vec![]
 249                 }
 250             ]
 251         );
 252         assert_eq!(
 253             read_rows(&b"foo\n \nbar\n"[..])
 254                 .flatten()
 255                 .collect::<Vec<_>>(),
 256             vec![
 257                 RowInput {
 258                     label: String::from("foo"),
 259                     entries: vec![]
 260                 },
 261                 RowInput {
 262                     label: String::from("bar"),
 263                     entries: vec![]
 264                 }
 265             ]
 266         );
 267         assert_eq!(
 268             read_rows(&b"foo  \n bar  \n"[..])
 269                 .flatten()
 270                 .collect::<Vec<_>>(),
 271             vec![RowInput {
 272                 label: String::from("foo"),
 273                 entries: vec![Entry::from("bar")]
 274             }]
 275         );
 276
 277         let bad = read_rows(&b" foo"[..]).next().unwrap();
 278         assert!(bad.is_err());
 279         assert!(format!("{bad:?}").contains("1: Entry with no header"));
 280
 281         let bad2 = read_rows(&b"foo\n\n bar"[..]).nth(1).unwrap();
 282         assert!(bad2.is_err());
 283         assert!(format!("{bad2:?}").contains("3: Entry with no header"));
 284     }
 285
 286     #[test]
 287     fn test_column_counts() {
 288         assert_eq!(
 289             column_counts(
 290                 &read_rows(&b"foo\n bar\n baz\n"[..])
 291                     .collect::<Result<Vec<_>, _>>()
 292                     .unwrap()
 293             ),
 294             vec![(1, String::from("bar")), (1, String::from("baz"))]
 295         );
 296         assert_eq!(
 297             column_counts(
 298                 &read_rows(&b"foo\n bar\n baz\nquux\n baz"[..])
 299                     .collect::<Result<Vec<_>, _>>()
 300                     .unwrap()
 301             ),
 302             vec![(1, String::from("bar")), (2, String::from("baz"))]
 303         );
 304         assert_eq!(
 305             column_counts(
 306                 &read_rows(&b"foo\n bar\n bar\n baz\n bar\nquux\n baz"[..])
 307                     .collect::<Result<Vec<_>, _>>()
 308                     .unwrap()
 309             ),
 310             vec![(1, String::from("bar")), (2, String::from("baz"))]
 311         );
 312         assert_eq!(
 313             column_counts(
 314                 &read_rows(&b"foo\n bar: 1\n bar: 2\n baz\n bar\nquux\n baz"[..])
 315                     .collect::<Result<Vec<_>, _>>()
 316                     .unwrap()
 317             ),
 318             vec![(1, String::from("bar")), (2, String::from("baz"))]
 319         );
 320     }
 321 }