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[tablify] / src / lib.rs
index 72a3add0ef2f9edccc34cc6f39b9ce8df9f79b56..2e9c7f64522544d0ea67964a63a6d866e08c1517 100644 (file)
-#[cfg(test)]
+use std::borrow::ToOwned;
+use std::collections::{HashMap, HashSet};
+use std::fmt::Write;
 use std::io::BufRead;
 use std::io::BufRead;
-#[cfg(test)]
 use std::iter::Iterator;
 
 use std::iter::Iterator;
 
+fn tally_marks(n: usize) -> String {
+    let fives = { 0..n / 5 }.map(|_| '𝍸');
+    let ones = { 0..n % 5 }.map(|_| '𝍷');
+    fives.chain(ones).collect()
+}
+
+#[derive(PartialEq, Eq, Debug)]
+struct Config {
+    column_threshold: usize,
+    static_columns: Vec<Option<String>>,
+    hidden_columns: HashSet<String>,
+    substitute_labels: HashMap<String, String>,
+}
+impl Config {
+    fn apply_command(&mut self, line_num: usize, cmd: &str) -> Result<(), std::io::Error> {
+        if let Some(threshold) = cmd.strip_prefix("col_threshold ") {
+            self.column_threshold = threshold.parse().map_err(|e| {
+                std::io::Error::new(
+                    std::io::ErrorKind::InvalidInput,
+                    format!("line {line_num}: col_threshold must be numeric: {e}"),
+                )
+            })?;
+        } else if let Some(col) = cmd.strip_prefix("hide ") {
+            self.hidden_columns.insert(col.to_owned());
+        } else if let Some(col) = cmd.strip_prefix("col ") {
+            self.static_columns.push(Some(col.to_owned()));
+        } else if cmd == "colsep" {
+            self.static_columns.push(None);
+        } else if let Some(directive) = cmd.strip_prefix("label ") {
+            match directive.split_once(':') {
+                None => {
+                    return Err(std::io::Error::new(
+                        std::io::ErrorKind::InvalidInput,
+                        format!("line {line_num}: Annotation missing ':'"),
+                    ))
+                }
+                Some((col, label)) => self
+                    .substitute_labels
+                    .insert(col.to_owned(), label.to_owned()),
+            };
+        } else {
+            return Err(std::io::Error::new(
+                std::io::ErrorKind::InvalidInput,
+                format!("line {line_num}: Unknown command: {cmd}"),
+            ));
+        }
+        Ok(())
+    }
+}
+impl Default for Config {
+    fn default() -> Self {
+        Self {
+            column_threshold: 2,
+            static_columns: vec![],
+            hidden_columns: HashSet::new(),
+            substitute_labels: HashMap::new(),
+        }
+    }
+}
+
+const HEADER: &str = r#"<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1">
+  <style>
+    td { text-align: center; }
+    /* h/t https://wabain.github.io/2019/10/13/css-rotated-table-header.html */
+    th, td { white-space: nowrap; }
+    th { text-align: left; font-weight: normal; }
+    th.spacer_row { height: .3em; }
+    .spacer_col { border: none; width: .2em; }
+    table { border-collapse: collapse }
+    tr.key > th { height: 10em; vertical-align: bottom; line-height: 1 }
+    tr.key > th > div { width: 1em; }
+    tr.key > th > div > div { width: 5em; transform-origin: bottom left; transform: translateX(1em) rotate(-65deg) }
+    td { border: thin solid gray; }
+    td.leftover { text-align: left; border: none; padding-left: .4em; }
+    td.yes { border: thin solid gray; background-color: #eee; }
+    /* h/t https://stackoverflow.com/questions/5687035/css-bolding-some-text-without-changing-its-containers-size/46452396#46452396 */
+    .highlight { text-shadow: -0.06ex 0 black, 0.06ex 0 black; }
+  </style>
+  <script>
+    function highlight(id)       { const e = document.getElementById(id); if (e) { e.classList.add(   "highlight"); } }
+    function clear_highlight(id) { const e = document.getElementById(id); if (e) { e.classList.remove("highlight"); } }
+    function h2(a, b)  {       highlight(a);       highlight(b); }
+    function ch2(a, b) { clear_highlight(a); clear_highlight(b); }
+  </script>
+</head>
+<body>
+  <table>
+    <tbody>
+"#;
+const FOOTER: &str = "    </tbody>
+  </table>
+</body>
+</html>";
+
+#[derive(PartialEq, Eq, Debug)]
+pub struct HTML(String);
+impl HTML {
+    fn escape(value: &str) -> HTML {
+        let mut escaped: String = String::new();
+        for c in value.chars() {
+            match c {
+                '>' => escaped.push_str("&gt;"),
+                '<' => escaped.push_str("&lt;"),
+                '\'' => escaped.push_str("&#39;"),
+                '"' => escaped.push_str("&quot;"),
+                '&' => escaped.push_str("&amp;"),
+                ok_c => escaped.push(ok_c),
+            }
+        }
+        HTML(escaped)
+    }
+}
+impl From<&str> for HTML {
+    fn from(value: &str) -> HTML {
+        HTML(String::from(value))
+    }
+}
+impl FromIterator<HTML> for HTML {
+    fn from_iter<T>(iter: T) -> HTML
+    where
+        T: IntoIterator<Item = HTML>,
+    {
+        HTML(iter.into_iter().map(|html| html.0).collect::<String>())
+    }
+}
+impl std::fmt::Display for HTML {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
 #[derive(Debug, PartialEq, Eq)]
 #[derive(Debug, PartialEq, Eq)]
-struct RowInput {
+enum InputLine<'a> {
+    Blank,
+    RowHeader(&'a str),
+    Entry(&'a str, Option<&'a str>),
+    Command(&'a str),
+}
+impl<'a> From<&'a str> for InputLine<'a> {
+    fn from(value: &'a str) -> InputLine<'a> {
+        let trimmed = value.trim_end();
+        if trimmed.is_empty() {
+            InputLine::Blank
+        } else if let Some(cmd) = trimmed.strip_prefix('!') {
+            InputLine::Command(cmd)
+        } else if !trimmed.starts_with(' ') {
+            InputLine::RowHeader(value.trim())
+        } else {
+            match value.split_once(':') {
+                None => InputLine::Entry(value.trim(), None),
+                Some((col, instance)) => InputLine::Entry(col.trim(), Some(instance.trim())),
+            }
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Eq)]
+struct Row {
     label: String,
     label: String,
-    entries: Vec<String>,
+    entries: HashMap<String, Vec<Option<String>>>,
+}
+
+#[derive(Debug, PartialEq, Eq)]
+enum Rowlike {
+    Row(Row),
+    Spacer,
 }
 
 }
 
-struct Reader<Input: Iterator<Item = Result<String, std::io::Error>>> {
-    input: Input,
-    row: Option<RowInput>,
+struct Reader<'cfg, Input: Iterator<Item = Result<String, std::io::Error>>> {
+    input: std::iter::Enumerate<Input>,
+    row: Option<Row>,
+    config: &'cfg mut Config,
 }
 }
-impl<Input: Iterator<Item = Result<String, std::io::Error>>> Reader<Input> {
-    #[cfg(test)]
-    fn new(input: Input) -> Self {
-        Self { input, row: None }
+impl<'cfg, Input: Iterator<Item = Result<String, std::io::Error>>> Reader<'cfg, Input> {
+    fn new(config: &'cfg mut Config, input: Input) -> Self {
+        Self {
+            input: input.enumerate(),
+            row: None,
+            config,
+        }
     }
 }
     }
 }
-impl<Input: Iterator<Item = Result<String, std::io::Error>>> Iterator for Reader<Input> {
-    type Item = Result<RowInput, std::io::Error>;
+impl<'cfg, Input: Iterator<Item = Result<String, std::io::Error>>> Iterator
+    for Reader<'cfg, Input>
+{
+    type Item = Result<Rowlike, std::io::Error>;
     fn next(&mut self) -> Option<Self::Item> {
         loop {
     fn next(&mut self) -> Option<Self::Item> {
         loop {
-            match self
-                .input
-                .next()
-                .map(|r| r.map(|line| String::from(line.trim_end())))
-            {
-                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();
+            match self.input.next() {
+                None => return Ok(std::mem::take(&mut self.row).map(Rowlike::Row)).transpose(),
+                Some((_, Err(e))) => return Some(Err(e)),
+                Some((n, Ok(line))) => match InputLine::from(line.as_ref()) {
+                    InputLine::Command(cmd) => {
+                        if let Err(e) = self.config.apply_command(n + 1, cmd) {
+                            return Some(Err(e));
+                        }
                     }
                     }
+                    InputLine::Blank if self.row.is_some() => {
+                        return Ok(std::mem::take(&mut self.row).map(Rowlike::Row)).transpose()
+                    }
+                    InputLine::Blank => return Some(Ok(Rowlike::Spacer)),
+                    InputLine::Entry(col, instance) => match &mut self.row {
+                        None => {
+                            return Some(Err(std::io::Error::other(format!(
+                                "line {}: Entry with no header",
+                                n + 1
+                            ))))
+                        }
+                        Some(ref mut row) => {
+                            row.entries
+                                .entry(col.to_owned())
+                                .and_modify(|is| is.push(instance.map(ToOwned::to_owned)))
+                                .or_insert_with(|| vec![instance.map(ToOwned::to_owned)]);
+                        }
+                    },
+                    InputLine::RowHeader(row) => {
+                        let prev = std::mem::take(&mut self.row);
+                        self.row = Some(Row {
+                            label: row.to_owned(),
+                            entries: HashMap::new(),
+                        });
+                        if prev.is_some() {
+                            return Ok(prev.map(Rowlike::Row)).transpose();
+                        }
+                    }
+                },
+            }
+        }
+    }
+}
+
+fn read_input(input: impl std::io::Read) -> Result<(Vec<Rowlike>, Config), std::io::Error> {
+    let mut config = Config::default();
+    let reader = Reader::new(&mut config, std::io::BufReader::new(input).lines());
+    reader
+        .collect::<Result<Vec<_>, _>>()
+        .map(|rows| (rows, config))
+}
+
+fn column_counts(rows: &[Rowlike]) -> Vec<(usize, String)> {
+    let empty = HashMap::new();
+    let mut counts: Vec<_> = rows
+        .iter()
+        .flat_map(|rl| match rl {
+            Rowlike::Row(r) => r.entries.keys(),
+            Rowlike::Spacer => empty.keys(),
+        })
+        .fold(HashMap::new(), |mut cs, col| {
+            cs.entry(col.to_owned())
+                .and_modify(|n| *n += 1)
+                .or_insert(1);
+            cs
+        })
+        .into_iter()
+        .map(|(col, n)| (n, col))
+        .collect();
+    counts.sort_unstable_by(|(an, acol), (bn, bcol)| bn.cmp(an).then(acol.cmp(bcol)));
+    counts
+}
+fn column_order(config: &Config, rows: &[Rowlike]) -> Vec<String> {
+    let static_columns: HashSet<&str> = config
+        .static_columns
+        .iter()
+        .flatten()
+        .map(std::string::String::as_str)
+        .collect();
+    column_counts(rows)
+        .into_iter()
+        .filter_map(|(n, col)| {
+            (n >= config.column_threshold
+                && !static_columns.contains(col.as_str())
+                && !config.hidden_columns.contains(&col))
+            .then_some(col)
+        })
+        .collect()
+}
+
+fn render_instances(instances: &[Option<String>]) -> HTML {
+    let mut tally = 0;
+    let mut out = vec![];
+    for ins in instances {
+        match ins {
+            None => tally += 1,
+            Some(content) => {
+                if tally > 0 {
+                    out.push(HTML(tally_marks(tally)));
+                    tally = 0;
                 }
                 }
+                out.push(HTML::escape(content));
             }
         }
     }
             }
         }
     }
+    if tally > 0 {
+        out.push(HTML(tally_marks(tally)));
+    }
+    HTML(
+        out.into_iter()
+            .map(|html| html.0) // Waiting for slice_concat_trait to stabilize
+            .collect::<Vec<_>>()
+            .join(" "),
+    )
 }
 
 }
 
-#[cfg(test)]
-fn read_rows(input: impl std::io::Read) -> impl Iterator<Item = Result<RowInput, std::io::Error>> {
-    Reader::new(std::io::BufReader::new(input).lines())
+fn render_cell(config: &Config, col: &str, row: &mut Row) -> HTML {
+    let row_label = HTML::escape(row.label.as_ref());
+    let col_label = HTML::escape(
+        config
+            .substitute_labels
+            .get(col)
+            .map_or(col, std::string::String::as_str),
+    );
+    let instances: Option<&Vec<Option<String>>> = row.entries.get(col);
+    let is_empty = match instances {
+        None => true,
+        Some(is) => is.iter().all(|ins| match ins {
+            None => false,
+            Some(content) => content == "×",
+        }),
+    };
+    let class = HTML::from(if is_empty { "" } else { r#" class="yes""# });
+    let contents = match instances {
+        None => HTML::from(""),
+        Some(is) => render_instances(is),
+    };
+    row.entries.remove(col);
+    HTML(format!(
+        r#"<td{class} onmouseover="h2('{row_label}','{col_label}')" onmouseout="ch2('{row_label}','{col_label}')">{contents}</td>"#
+    ))
+}
+
+fn render_leftover(notcol: &str, instances: &[Option<String>]) -> HTML {
+    let label = HTML::escape(notcol);
+    if instances.len() == 1 && instances[0].is_none() {
+        HTML(format!("{label}"))
+    } else {
+        let rest = render_instances(instances);
+        HTML(format!("{label}: {rest}"))
+    }
+}
+
+fn render_all_leftovers(config: &Config, row: &Row) -> HTML {
+    let mut order: Vec<_> = row
+        .entries
+        .keys()
+        .filter(|&col| !config.hidden_columns.contains(col))
+        .collect();
+    order.sort_unstable();
+    HTML(
+        order
+            .into_iter()
+            .map(|notcol| render_leftover(notcol, row.entries.get(notcol).expect("Key vanished?!")))
+            .map(|html| html.0) // Waiting for slice_concat_trait to stabilize
+            .collect::<Vec<_>>()
+            .join(", "),
+    )
+}
+
+fn render_row(config: &Config, columns: &[String], rowlike: &mut Rowlike) -> HTML {
+    match rowlike {
+        Rowlike::Spacer => HTML::from("<tr><th class=\"spacer_row\"></th></tr>\n"),
+        Rowlike::Row(row) => {
+            let row_label = HTML::escape(row.label.as_ref());
+            let static_cells = config
+                .static_columns
+                .iter()
+                .map(|ocol| match ocol {
+                    Some(col) if config.hidden_columns.contains(col) => HTML::from(""),
+                    Some(col) => render_cell(config, col, row),
+                    None => HTML::from(r#"<td class="spacer_col"></td>"#),
+                })
+                .collect::<HTML>();
+            let dynamic_cells = columns
+                .iter()
+                .filter(|&col| !config.hidden_columns.contains(col))
+                .map(|col| render_cell(config, col, row))
+                .collect::<HTML>();
+            let leftovers = render_all_leftovers(config, row);
+            HTML(format!(
+                "<tr><th id=\"{row_label}\">{row_label}</th>{static_cells}{dynamic_cells}<td class=\"leftover\" onmouseover=\"highlight('{row_label}')\" onmouseout=\"clear_highlight('{row_label}')\">{leftovers}</td></tr>\n"
+            ))
+        }
+    }
 }
 
 }
 
-pub fn tablify(_input: &impl std::io::Read) -> String {
-    String::from("Hello, world!")
+fn column_header_labels<'a>(
+    config: &'a Config,
+    columns: &'a [String],
+) -> impl Iterator<Item = Option<&'a String>> {
+    let static_columns = config.static_columns.iter().map(|oc| oc.as_ref());
+    let dynamic_columns = columns.iter().map(Some);
+    static_columns
+        .chain(dynamic_columns)
+        .filter(|ocol| ocol.map_or(true, |col| !config.hidden_columns.contains(col)))
+        .map(|ocol| {
+            ocol.map(|col| match config.substitute_labels.get(col) {
+                None => col,
+                Some(substitute) => substitute,
+            })
+        })
+}
+
+fn render_column_headers(config: &Config, columns: &[String]) -> HTML {
+    HTML(
+        String::from(r#"<tr class="key"><th></th>"#)
+            + &column_header_labels(config, columns).fold(String::new(), |mut acc, ocol| {
+                match ocol {
+                    Some(col) => {
+                        let col_header = HTML::escape(col);
+                        write!(
+                            &mut acc,
+                            r#"<th id="{col_header}"><div><div>{col_header}</div></div></th>"#
+                        )
+                    }
+                    None => write!(&mut acc, r#"<th class="col_spacer"></th>"#),
+                }
+                .unwrap();
+                acc
+            })
+            + "</tr>\n",
+    )
+}
+
+/// # Errors
+///
+/// Will return `Err` if
+///   * there's an i/o error while reading `input`
+///   * the log has invalid syntax:
+///     * an indented line with no preceding non-indented line
+pub fn tablify(input: impl std::io::Read) -> Result<HTML, std::io::Error> {
+    let (rows, config) = read_input(input)?;
+    let columns = column_order(&config, &rows);
+    Ok(HTML(format!(
+        "{HEADER}{}{}{FOOTER}",
+        render_column_headers(&config, &columns),
+        rows.into_iter()
+            .map(|mut r| render_row(&config, &columns, &mut r))
+            .collect::<HTML>()
+    )))
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
 
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
 
+    #[test]
+    fn test_parse_line() {
+        assert_eq!(InputLine::from(""), InputLine::Blank);
+        assert_eq!(InputLine::from(" "), InputLine::Blank);
+        assert_eq!(InputLine::from("foo"), InputLine::RowHeader("foo"));
+        assert_eq!(InputLine::from("foo "), InputLine::RowHeader("foo"));
+        assert_eq!(InputLine::from(" foo"), InputLine::Entry("foo", None));
+        assert_eq!(
+            InputLine::from(" foo:bar"),
+            InputLine::Entry("foo", Some("bar"))
+        );
+        assert_eq!(
+            InputLine::from(" foo: bar"),
+            InputLine::Entry("foo", Some("bar"))
+        );
+        assert_eq!(
+            InputLine::from(" foo: bar "),
+            InputLine::Entry("foo", Some("bar"))
+        );
+        assert_eq!(
+            InputLine::from(" foo:  bar "),
+            InputLine::Entry("foo", Some("bar"))
+        );
+        assert_eq!(
+            InputLine::from(" foo :  bar "),
+            InputLine::Entry("foo", Some("bar"))
+        );
+    }
+
+    #[test]
+    fn test_tally_marks() {
+        assert_eq!(tally_marks(1), "𝍷");
+        assert_eq!(tally_marks(2), "𝍷𝍷");
+        assert_eq!(tally_marks(3), "𝍷𝍷𝍷");
+        assert_eq!(tally_marks(4), "𝍷𝍷𝍷𝍷");
+        assert_eq!(tally_marks(5), "𝍸");
+        assert_eq!(tally_marks(6), "𝍸𝍷");
+        assert_eq!(tally_marks(7), "𝍸𝍷𝍷");
+        assert_eq!(tally_marks(8), "𝍸𝍷𝍷𝍷");
+        assert_eq!(tally_marks(9), "𝍸𝍷𝍷𝍷𝍷");
+        assert_eq!(tally_marks(10), "𝍸𝍸");
+        assert_eq!(tally_marks(11), "𝍸𝍸𝍷");
+    }
+
+    fn read_rows(input: impl std::io::Read) -> Result<Vec<Rowlike>, std::io::Error> {
+        read_input(input).map(|(rows, _)| rows)
+    }
+    fn read_config(input: impl std::io::Read) -> Result<Config, std::io::Error> {
+        read_input(input).map(|(_, config)| config)
+    }
     #[test]
     fn test_read_rows() {
         assert_eq!(
     #[test]
     fn test_read_rows() {
         assert_eq!(
-            read_rows(&b"foo"[..]).flatten().collect::<Vec<_>>(),
-            vec![RowInput {
-                label: String::from("foo"),
-                entries: vec![]
-            }]
+            read_rows(&b"foo"[..]).unwrap(),
+            vec![Rowlike::Row(Row {
+                label: "foo".to_owned(),
+                entries: HashMap::new(),
+            })]
         );
         assert_eq!(
         );
         assert_eq!(
-            read_rows(&b"bar"[..]).flatten().collect::<Vec<_>>(),
-            vec![RowInput {
-                label: String::from("bar"),
-                entries: vec![]
-            }]
+            read_rows(&b"bar"[..]).unwrap(),
+            vec![Rowlike::Row(Row {
+                label: "bar".to_owned(),
+                entries: HashMap::new(),
+            })]
         );
         assert_eq!(
         );
         assert_eq!(
-            read_rows(&b"foo\nbar\n"[..]).flatten().collect::<Vec<_>>(),
+            read_rows(&b"foo\nbar\n"[..]).unwrap(),
             vec![
             vec![
-                RowInput {
-                    label: String::from("foo"),
-                    entries: vec![]
-                },
-                RowInput {
-                    label: String::from("bar"),
-                    entries: vec![]
-                }
+                Rowlike::Row(Row {
+                    label: "foo".to_owned(),
+                    entries: HashMap::new(),
+                }),
+                Rowlike::Row(Row {
+                    label: "bar".to_owned(),
+                    entries: HashMap::new(),
+                })
             ]
         );
         assert_eq!(
             ]
         );
         assert_eq!(
-            read_rows(&b"foo\n bar\n"[..]).flatten().collect::<Vec<_>>(),
-            vec![RowInput {
-                label: String::from("foo"),
-                entries: vec![String::from("bar")]
-            }]
+            read_rows(&b"foo\n bar\n"[..]).unwrap(),
+            vec![Rowlike::Row(Row {
+                label: "foo".to_owned(),
+                entries: HashMap::from([("bar".to_owned(), vec![None])]),
+            })]
         );
         assert_eq!(
         );
         assert_eq!(
-            read_rows(&b"foo\n bar\n baz\n"[..])
-                .flatten()
-                .collect::<Vec<_>>(),
-            vec![RowInput {
-                label: String::from("foo"),
-                entries: vec![String::from("bar"), String::from("baz")]
-            }]
+            read_rows(&b"foo\n bar\n baz\n"[..]).unwrap(),
+            vec![Rowlike::Row(Row {
+                label: "foo".to_owned(),
+                entries: HashMap::from([
+                    ("bar".to_owned(), vec![None]),
+                    ("baz".to_owned(), vec![None])
+                ]),
+            })]
         );
         assert_eq!(
         );
         assert_eq!(
-            read_rows(&b"foo\n\nbar\n"[..])
-                .flatten()
-                .collect::<Vec<_>>(),
+            read_rows(&b"foo\n\nbar\n"[..]).unwrap(),
             vec![
             vec![
-                RowInput {
-                    label: String::from("foo"),
-                    entries: vec![]
-                },
-                RowInput {
-                    label: String::from("bar"),
-                    entries: vec![]
-                }
+                Rowlike::Row(Row {
+                    label: "foo".to_owned(),
+                    entries: HashMap::new(),
+                }),
+                Rowlike::Row(Row {
+                    label: "bar".to_owned(),
+                    entries: HashMap::new(),
+                })
             ]
         );
         assert_eq!(
             ]
         );
         assert_eq!(
-            read_rows(&b"foo\n \nbar\n"[..])
-                .flatten()
-                .collect::<Vec<_>>(),
+            read_rows(&b"foo\n\n\nbar\n"[..]).unwrap(),
             vec![
             vec![
-                RowInput {
-                    label: String::from("foo"),
-                    entries: vec![]
-                },
-                RowInput {
-                    label: String::from("bar"),
-                    entries: vec![]
-                }
+                Rowlike::Row(Row {
+                    label: "foo".to_owned(),
+                    entries: HashMap::new(),
+                }),
+                Rowlike::Spacer,
+                Rowlike::Row(Row {
+                    label: "bar".to_owned(),
+                    entries: HashMap::new(),
+                })
             ]
         );
         assert_eq!(
             ]
         );
         assert_eq!(
-            read_rows(&b"foo  \n bar  \n"[..])
-                .flatten()
-                .collect::<Vec<_>>(),
-            vec![RowInput {
-                label: String::from("foo"),
-                entries: vec![String::from("bar")]
-            }]
+            read_rows(&b"foo\n \nbar\n"[..]).unwrap(),
+            vec![
+                Rowlike::Row(Row {
+                    label: "foo".to_owned(),
+                    entries: HashMap::new(),
+                }),
+                Rowlike::Row(Row {
+                    label: "bar".to_owned(),
+                    entries: HashMap::new(),
+                })
+            ]
+        );
+        assert_eq!(
+            read_rows(&b"foo  \n bar  \n"[..]).unwrap(),
+            vec![Rowlike::Row(Row {
+                label: "foo".to_owned(),
+                entries: HashMap::from([("bar".to_owned(), vec![None])]),
+            })]
         );
 
         );
 
-        let bad = read_rows(&b" foo"[..]).next().unwrap();
+        let bad = read_rows(&b" foo"[..]);
         assert!(bad.is_err());
         assert!(bad.is_err());
-        assert!(format!("{bad:?}").contains("Entry with no header"));
+        assert!(format!("{bad:?}").contains("line 1: Entry with no header"));
 
 
-        let bad2 = read_rows(&b"foo\n\n bar"[..]).nth(1).unwrap();
+        let bad2 = read_rows(&b"foo\n\n bar"[..]);
         assert!(bad2.is_err());
         assert!(bad2.is_err());
-        assert!(format!("{bad2:?}").contains("Entry with no header"));
+        assert!(format!("{bad2:?}").contains("line 3: Entry with no header"));
+    }
+
+    #[test]
+    fn test_read_config() {
+        assert_eq!(
+            read_config(&b"!col_threshold 10"[..])
+                .unwrap()
+                .column_threshold,
+            10
+        );
+        assert_eq!(
+            read_config(&b"!col foo"[..]).unwrap().static_columns,
+            vec![Some("foo".to_owned())]
+        );
+        assert_eq!(
+            read_config(&b"!label foo:bar"[..])
+                .unwrap()
+                .substitute_labels["foo"],
+            "bar"
+        );
+
+        let bad_command = read_config(&b"!no such command"[..]);
+        assert!(bad_command.is_err());
+        assert!(format!("{bad_command:?}").contains("line 1: Unknown command"));
+
+        let bad_num = read_config(&b"!col_threshold foo"[..]);
+        assert!(bad_num.is_err());
+        assert!(format!("{bad_num:?}").contains("line 1: col_threshold must be numeric"));
+
+        let bad_sub = read_config(&b"!label foo"[..]);
+        assert!(bad_sub.is_err());
+        assert!(format!("{bad_sub:?}").contains("line 1: Annotation missing ':'"));
+    }
+
+    #[test]
+    fn test_column_counts() {
+        assert_eq!(
+            column_counts(&read_rows(&b"foo\n bar\n baz\n"[..]).unwrap()),
+            vec![(1, String::from("bar")), (1, String::from("baz"))]
+        );
+        assert_eq!(
+            column_counts(&read_rows(&b"foo\n bar\n baz\nquux\n baz"[..]).unwrap()),
+            vec![(2, String::from("baz")), (1, String::from("bar"))]
+        );
+        assert_eq!(
+            column_counts(&read_rows(&b"foo\n bar\n bar\n baz\n bar\nquux\n baz"[..]).unwrap()),
+            vec![(2, String::from("baz")), (1, String::from("bar"))]
+        );
+        assert_eq!(
+            column_counts(
+                &read_rows(&b"foo\n bar: 1\n bar: 2\n baz\n bar\nquux\n baz"[..]).unwrap()
+            ),
+            vec![(2, String::from("baz")), (1, String::from("bar"))]
+        );
+    }
+
+    #[test]
+    fn test_column_header_labels() {
+        let mut cfg = Config::default();
+
+        assert!(column_header_labels(&cfg, &["foo".to_owned()]).eq([Some(&"foo".to_owned())]));
+
+        cfg.static_columns.push(Some("bar".to_owned()));
+        assert!(column_header_labels(&cfg, &["foo".to_owned()])
+            .eq([Some(&"bar".to_owned()), Some(&"foo".to_owned())]));
+
+        cfg.static_columns.push(None);
+        assert!(column_header_labels(&cfg, &["foo".to_owned()]).eq([
+            Some(&"bar".to_owned()),
+            None,
+            Some(&"foo".to_owned())
+        ]));
+
+        cfg.substitute_labels
+            .insert("foo".to_owned(), "foo (bits)".to_owned());
+        assert!(column_header_labels(&cfg, &["foo".to_owned()]).eq([
+            Some(&"bar".to_owned()),
+            None,
+            Some(&"foo (bits)".to_owned())
+        ]));
+
+        cfg.hidden_columns.insert("foo".to_owned());
+        assert!(column_header_labels(&cfg, &["foo".to_owned()]).eq([Some(&"bar".to_owned()), None]));
+
+        cfg.hidden_columns.insert("bar".to_owned());
+        assert!(column_header_labels(&cfg, &["foo".to_owned()]).eq([None]));
+    }
+
+    #[test]
+    fn test_render_cell() {
+        assert_eq!(
+            render_cell(
+                &Config::default(),
+                "foo",
+                &mut Row {
+                    label: "nope".to_owned(),
+                    entries: HashMap::new(),
+                }
+            ),
+            HTML::from(
+                r#"<td onmouseover="h2('nope','foo')" onmouseout="ch2('nope','foo')"></td>"#
+            )
+        );
+        assert_eq!(
+            render_cell(
+                &Config::default(),
+                "foo",
+                &mut Row {
+                    label: "nope".to_owned(),
+                    entries: HashMap::from([("bar".to_owned(), vec![None])]),
+                }
+            ),
+            HTML::from(
+                r#"<td onmouseover="h2('nope','foo')" onmouseout="ch2('nope','foo')"></td>"#
+            )
+        );
+        assert_eq!(
+            render_cell(
+                &Config::default(),
+                "foo",
+                &mut Row {
+                    label: "nope".to_owned(),
+                    entries: HashMap::from([("foo".to_owned(), vec![None])]),
+                }
+            ),
+            HTML::from(
+                r#"<td class="yes" onmouseover="h2('nope','foo')" onmouseout="ch2('nope','foo')">𝍷</td>"#
+            )
+        );
+        assert_eq!(
+            render_cell(
+                &Config::default(),
+                "foo",
+                &mut Row {
+                    label: "nope".to_owned(),
+                    entries: HashMap::from([("foo".to_owned(), vec![None, None])]),
+                }
+            ),
+            HTML::from(
+                r#"<td class="yes" onmouseover="h2('nope','foo')" onmouseout="ch2('nope','foo')">𝍷𝍷</td>"#
+            )
+        );
+        assert_eq!(
+            render_cell(
+                &Config::default(),
+                "foo",
+                &mut Row {
+                    label: "nope".to_owned(),
+                    entries: HashMap::from([(
+                        "foo".to_owned(),
+                        vec![Some("5".to_owned()), Some("10".to_owned())]
+                    )]),
+                }
+            ),
+            HTML::from(
+                r#"<td class="yes" onmouseover="h2('nope','foo')" onmouseout="ch2('nope','foo')">5 10</td>"#
+            )
+        );
+        assert_eq!(
+            render_cell(
+                &Config::default(),
+                "foo",
+                &mut Row {
+                    label: "nope".to_owned(),
+                    entries: HashMap::from([("foo".to_owned(), vec![Some("5".to_owned()), None])]),
+                }
+            ),
+            HTML::from(
+                r#"<td class="yes" onmouseover="h2('nope','foo')" onmouseout="ch2('nope','foo')">5 𝍷</td>"#
+            )
+        );
+        assert_eq!(
+            render_cell(
+                &Config::default(),
+                "foo",
+                &mut Row {
+                    label: "nope".to_owned(),
+                    entries: HashMap::from([("foo".to_owned(), vec![Some("×".to_owned())])]),
+                }
+            ),
+            HTML::from(
+                r#"<td onmouseover="h2('nope','foo')" onmouseout="ch2('nope','foo')">×</td>"#
+            )
+        );
+        assert_eq!(
+            render_cell(
+                &Config::default(),
+                "heart",
+                &mut Row {
+                    label: "nope".to_owned(),
+                    entries: HashMap::from([("heart".to_owned(), vec![Some("<3".to_owned())])]),
+                }
+            ),
+            HTML::from(
+                r#"<td class="yes" onmouseover="h2('nope','heart')" onmouseout="ch2('nope','heart')">&lt;3</td>"#
+            )
+        );
+        assert_eq!(
+            render_cell(
+                &Config::default(),
+                "foo",
+                &mut Row {
+                    label: "bob's".to_owned(),
+                    entries: HashMap::from([("foo".to_owned(), vec![None])]),
+                }
+            ),
+            HTML::from(
+                r#"<td class="yes" onmouseover="h2('bob&#39;s','foo')" onmouseout="ch2('bob&#39;s','foo')">𝍷</td>"#
+            )
+        );
+        let mut r = Row {
+            label: "nope".to_owned(),
+            entries: HashMap::from([
+                ("foo".to_owned(), vec![None]),
+                ("baz".to_owned(), vec![None]),
+            ]),
+        };
+        assert_eq!(r.entries.len(), 2);
+        render_cell(&Config::default(), "foo", &mut r);
+        assert_eq!(r.entries.len(), 1);
+        render_cell(&Config::default(), "bar", &mut r);
+        assert_eq!(r.entries.len(), 1);
+        render_cell(&Config::default(), "baz", &mut r);
+        assert_eq!(r.entries.len(), 0);
+    }
+
+    #[test]
+    fn test_render_leftovers() {
+        assert_eq!(
+            render_all_leftovers(
+                &Config::default(),
+                &Row {
+                    label: "nope".to_owned(),
+                    entries: HashMap::from([("foo".to_owned(), vec![None])]),
+                }
+            ),
+            HTML::from("foo")
+        );
+        assert_eq!(
+            render_all_leftovers(
+                &Config::default(),
+                &Row {
+                    label: "nope".to_owned(),
+                    entries: HashMap::from([
+                        ("foo".to_owned(), vec![None]),
+                        ("bar".to_owned(), vec![None])
+                    ]),
+                }
+            ),
+            HTML::from("bar, foo")
+        );
+        assert_eq!(
+            render_all_leftovers(
+                &Config::default(),
+                &Row {
+                    label: "nope".to_owned(),
+                    entries: HashMap::from([
+                        ("foo".to_owned(), vec![None]),
+                        ("bar".to_owned(), vec![None, None])
+                    ]),
+                }
+            ),
+            HTML::from("bar: 𝍷𝍷, foo")
+        );
+        assert_eq!(
+            render_all_leftovers(
+                &Config {
+                    column_threshold: 2,
+                    static_columns: vec![],
+                    hidden_columns: HashSet::from(["private".to_owned()]),
+                    substitute_labels: HashMap::new(),
+                },
+                &Row {
+                    label: "nope".to_owned(),
+                    entries: HashMap::from([("private".to_owned(), vec![None]),]),
+                }
+            ),
+            HTML::from("")
+        );
+    }
+
+    #[test]
+    fn test_render_row() {
+        assert_eq!(
+            render_row(
+                &Config::default(),
+                &["foo".to_owned()],
+                &mut Rowlike::Row(Row {
+                    label: "nope".to_owned(),
+                    entries: HashMap::from([("bar".to_owned(), vec![None])]),
+                })
+            ),
+            HTML::from(
+                r#"<tr><th id="nope">nope</th><td onmouseover="h2('nope','foo')" onmouseout="ch2('nope','foo')"></td><td class="leftover" onmouseover="highlight('nope')" onmouseout="clear_highlight('nope')">bar</td></tr>
+"#
+            )
+        );
+        assert_eq!(
+            render_row(
+                &Config {
+                    column_threshold: 0,
+                    static_columns: vec![Some("foo".to_owned()), Some("bar".to_owned())],
+                    hidden_columns: HashSet::new(),
+                    substitute_labels: HashMap::new(),
+                },
+                &["baz".to_owned()],
+                &mut Rowlike::Row(Row {
+                    label: "nope".to_owned(),
+                    entries: HashMap::from([
+                        ("bar".to_owned(), vec![Some("r".to_owned())]),
+                        ("baz".to_owned(), vec![Some("z".to_owned())]),
+                        ("foo".to_owned(), vec![Some("f".to_owned())]),
+                    ]),
+                })
+            ),
+            HTML::from(
+                r#"<tr><th id="nope">nope</th><td class="yes" onmouseover="h2('nope','foo')" onmouseout="ch2('nope','foo')">f</td><td class="yes" onmouseover="h2('nope','bar')" onmouseout="ch2('nope','bar')">r</td><td class="yes" onmouseover="h2('nope','baz')" onmouseout="ch2('nope','baz')">z</td><td class="leftover" onmouseover="highlight('nope')" onmouseout="clear_highlight('nope')"></td></tr>
+"#
+            )
+        );
+        assert_eq!(
+            render_row(
+                &Config {
+                    column_threshold: 0,
+                    static_columns: vec![Some("foo".to_owned()), None, Some("bar".to_owned())],
+                    hidden_columns: HashSet::new(),
+                    substitute_labels: HashMap::new(),
+                },
+                &[],
+                &mut Rowlike::Row(Row {
+                    label: "nope".to_owned(),
+                    entries: HashMap::from([
+                        ("bar".to_owned(), vec![Some("r".to_owned())]),
+                        ("foo".to_owned(), vec![Some("f".to_owned())]),
+                    ]),
+                })
+            ),
+            HTML::from(
+                r#"<tr><th id="nope">nope</th><td class="yes" onmouseover="h2('nope','foo')" onmouseout="ch2('nope','foo')">f</td><td class="spacer_col"></td><td class="yes" onmouseover="h2('nope','bar')" onmouseout="ch2('nope','bar')">r</td><td class="leftover" onmouseover="highlight('nope')" onmouseout="clear_highlight('nope')"></td></tr>
+"#
+            )
+        );
+        assert_eq!(
+            render_row(
+                &Config {
+                    column_threshold: 0,
+                    static_columns: vec![],
+                    hidden_columns: HashSet::from(["foo".to_owned()]),
+                    substitute_labels: HashMap::new(),
+                },
+                &[],
+                &mut Rowlike::Row(Row {
+                    label: "nope".to_owned(),
+                    entries: HashMap::from([("foo".to_owned(), vec![Some("f".to_owned())]),]),
+                })
+            ),
+            HTML::from(
+                r#"<tr><th id="nope">nope</th><td class="leftover" onmouseover="highlight('nope')" onmouseout="clear_highlight('nope')"></td></tr>
+"#
+            )
+        );
+        assert_eq!(
+            render_row(
+                &Config {
+                    column_threshold: 0,
+                    static_columns: vec![Some("foo".to_owned())],
+                    hidden_columns: HashSet::from(["foo".to_owned()]),
+                    substitute_labels: HashMap::new(),
+                },
+                &[],
+                &mut Rowlike::Row(Row {
+                    label: "nope".to_owned(),
+                    entries: HashMap::from([("foo".to_owned(), vec![Some("f".to_owned())]),]),
+                })
+            ),
+            HTML::from(
+                r#"<tr><th id="nope">nope</th><td class="leftover" onmouseover="highlight('nope')" onmouseout="clear_highlight('nope')"></td></tr>
+"#
+            )
+        );
+        assert_eq!(
+            render_row(
+                &Config {
+                    column_threshold: 0,
+                    static_columns: vec![],
+                    hidden_columns: HashSet::new(),
+                    substitute_labels: HashMap::from([("foo".to_owned(), "bar".to_owned())]),
+                },
+                &["foo".to_owned()],
+                &mut Rowlike::Row(Row {
+                    label: "nope".to_owned(),
+                    entries: HashMap::from([("foo".to_owned(), vec![None])]),
+                })
+            ),
+            HTML::from(
+                r#"<tr><th id="nope">nope</th><td class="yes" onmouseover="h2('nope','bar')" onmouseout="ch2('nope','bar')">𝍷</td><td class="leftover" onmouseover="highlight('nope')" onmouseout="clear_highlight('nope')"></td></tr>
+"#
+            )
+        );
     }
 }
     }
 }