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