iota_sdk_types/
utils.rs

1// Copyright (c) 2026 IOTA Stiftung
2// SPDX-License-Identifier: Apache-2.0
3
4/// Write an iterator of items to a formatter, joined by a separator.
5///
6/// If `delimiters` is provided, the output is wrapped in the given left and
7/// right delimiter strings. An empty iterator produces no output at all (not
8/// even delimiters).
9///
10/// # Examples
11///
12/// ```
13/// use std::fmt;
14///
15/// struct Nums(Vec<i32>);
16///
17/// impl fmt::Display for Nums {
18///     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
19///         iota_sdk_types::utils::write_sep(f, &self.0, Some(("[", "]")), ", ")
20///     }
21/// }
22///
23/// assert_eq!(Nums(vec![1, 2, 3]).to_string(), "[1, 2, 3]");
24/// assert_eq!(Nums(vec![]).to_string(), "");
25/// ```
26pub fn write_sep<T: core::fmt::Display>(
27    f: &mut core::fmt::Formatter<'_>,
28    items: impl IntoIterator<Item = T>,
29    delimiters: Option<(&str, &str)>,
30    separator: &str,
31) -> std::fmt::Result {
32    let mut xs = items.into_iter();
33    let Some(x) = xs.next() else {
34        return Ok(());
35    };
36    if let Some((l, _)) = delimiters {
37        write!(f, "{l}")?;
38    }
39    write!(f, "{x}")?;
40    for x in xs {
41        write!(f, "{separator}{x}")?;
42    }
43    if let Some((_, r)) = delimiters {
44        write!(f, "{r}")?;
45    }
46    Ok(())
47}
iota_sdk_types/utils.rs

iota_sdk_types/
utils.rs
