kg_display/
lib.rs

1pub mod fmt;
2
3use std::ops::{Deref, DerefMut};
4
5pub struct PrettyPrinter<'a, 'b: 'a> {
6    padding: &'a str,
7    fmt: &'a mut std::fmt::Formatter<'b>,
8    on_newline: bool,
9}
10
11impl<'a, 'b> PrettyPrinter<'a, 'b> {
12    pub fn new(fmt: &'a mut std::fmt::Formatter<'b>, padding: &'a str) -> PrettyPrinter<'a, 'b> {
13        PrettyPrinter {
14            padding: padding,
15            fmt: fmt,
16            on_newline: false,
17        }
18    }
19
20    pub fn fmt(&'a mut self) -> &'a mut std::fmt::Formatter<'b> {
21        self.fmt
22    }
23}
24
25impl<'a, 'b> Deref for PrettyPrinter<'a, 'b> {
26    type Target = std::fmt::Formatter<'b>;
27
28    fn deref(&self) -> &Self::Target {
29        self.fmt
30    }
31}
32
33impl<'a, 'b> DerefMut for PrettyPrinter<'a, 'b> {
34    fn deref_mut(&mut self) -> &mut Self::Target {
35        self.fmt
36    }
37}
38
39impl<'a, 'b> std::fmt::Write for PrettyPrinter<'a, 'b> {
40    fn write_str(&mut self, mut s: &str) -> std::fmt::Result {
41        while !s.is_empty() {
42            if self.on_newline {
43                self.fmt.write_str(self.padding)?;
44            }
45
46            let split = match s.find('\n') {
47                Some(pos) => {
48                    self.on_newline = true;
49                    pos + 1
50                }
51                None => {
52                    self.on_newline = false;
53                    s.len()
54                }
55            };
56            self.fmt.write_str(&s[..split])?;
57            s = &s[split..];
58        }
59
60        Ok(())
61    }
62}
63
64
65pub struct ListDisplay<'a, T: std::fmt::Display + 'a>(pub &'a [T]);
66
67impl<'a, T: std::fmt::Display + 'a> std::fmt::Display for ListDisplay<'a, T> {
68    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
69        let mut i = self.0.iter().peekable();
70        while let Some(e) = i.next() {
71            e.fmt(f)?;
72            if i.peek().is_some() {
73                write!(f, ", ")?;
74            }
75        }
76        Ok(())
77    }
78}
kg_display/lib.rs

kg_display/
lib.rs
