printtable/
lib.rs

1use std::cmp;
2use std::io::{self, Write};
3use std::iter::IntoIterator;
4use std::marker::Sized;
5
6fn prepare_line<U, V>(line: U, col_widths: &mut Vec<usize>, cell_strs: &mut Vec<String>)
7where
8    U: IntoIterator<Item = V>,
9    V: ToString + Sized,
10{
11    for (i, cell) in line.into_iter().enumerate() {
12        if i >= col_widths.len() {
13            col_widths.resize(i + 1, 0);
14        }
15        let cell_str = cell.to_string();
16        col_widths[i] = cmp::max(col_widths[i], cell_str.len());
17        cell_strs.push(cell_str);
18    }
19}
20
21pub fn write<H, I, T, U, V, W>(mut writer: W, header: H, mat: T) -> Result<(), io::Error>
22where
23    H: IntoIterator<Item = I>,
24    I: ToString + Sized,
25    T: IntoIterator<Item = U>,
26    U: IntoIterator<Item = V>,
27    V: ToString + Sized,
28    W: Write,
29{
30    let mut col_widths = vec![];
31    let mut cell_strs = vec![];
32    prepare_line(header, &mut col_widths, &mut cell_strs);
33    for line in mat {
34        prepare_line(line, &mut col_widths, &mut cell_strs);
35    }
36    let mut col = 0;
37    let width = col_widths.len();
38    let mut in_header = true;
39    for cell_str in &cell_strs {
40        writer.write_all(format!("{}", cell_str).as_bytes())?;
41        for _ in cell_str.len()..col_widths[col] {
42            writer.write_all(b" ")?;
43        }
44        col += 1;
45        if col == width {
46            col = 0;
47            writer.write_all(b"\n")?;
48            if in_header {
49                for (i, col_width) in (&col_widths).iter().enumerate() {
50                    for _ in 0..*col_width {
51                        writer.write_all(b"-")?;
52                    }
53                    if i < width - 1 {
54                        writer.write_all(b"-+-")?;
55                    }
56                }
57                writer.write_all(b"\n")?;
58                in_header = false
59            }
60        } else {
61            writer.write_all(b" | ")?;
62        }
63    }
64    Ok(())
65}
printtable/lib.rs

printtable/
lib.rs
