ruff_db/
display.rs

1use std::fmt::{self, Display, Formatter};
2
3pub trait FormatterJoinExtension<'b> {
4    fn join<'a>(&'a mut self, separator: &'static str) -> Join<'a, 'b>;
5}
6
7impl<'b> FormatterJoinExtension<'b> for Formatter<'b> {
8    fn join<'a>(&'a mut self, separator: &'static str) -> Join<'a, 'b> {
9        Join {
10            fmt: self,
11            separator,
12            result: fmt::Result::Ok(()),
13            seen_first: false,
14        }
15    }
16}
17
18pub struct Join<'a, 'b> {
19    fmt: &'a mut Formatter<'b>,
20    separator: &'static str,
21    result: fmt::Result,
22    seen_first: bool,
23}
24
25impl Join<'_, '_> {
26    pub fn entry(&mut self, item: &dyn Display) -> &mut Self {
27        if self.seen_first {
28            self.result = self
29                .result
30                .and_then(|()| self.fmt.write_str(self.separator));
31        } else {
32            self.seen_first = true;
33        }
34        self.result = self.result.and_then(|()| item.fmt(self.fmt));
35        self
36    }
37
38    pub fn finish(&mut self) -> fmt::Result {
39        self.result
40    }
41}
ruff_db/display.rs

ruff_db/
display.rs
