malachite_nz/integer_vector/conversion/string/from_string.rs
1// Copyright © 2026 Mikhail Hogrefe
2//
3// This file is part of Malachite.
4//
5// Malachite is free software: you can redistribute it and/or modify it under the terms of the GNU
6// Lesser General Public License (LGPL) as published by the Free Software Foundation; either version
7// 3 of the License, or (at your option) any later version. See <https://www.gnu.org/licenses/>.
8
9use crate::integer::Integer;
10use crate::integer_vector::IntegerVector;
11use alloc::vec::Vec;
12use core::str::FromStr;
13
14impl FromStr for IntegerVector {
15 type Err = ();
16
17 /// Converts a string to an [`IntegerVector`].
18 ///
19 /// This reads back what [`Display`](core::fmt::Display) writes: the elements in order,
20 /// separated by `", "` and enclosed in parentheses, with `()` for the 0-dimensional vector.
21 /// Each element is read the way [`Integer::from_str`] reads one, so it may have leading zeros
22 /// and a single leading `'-'` or `'+'`. Any other spacing, such as `(1,2)` or `( 1, 2 )`, is
23 /// rejected, as is an empty element.
24 ///
25 /// If the string does not represent an [`IntegerVector`], an `Err` is returned.
26 ///
27 /// # Worst-case complexity
28 /// $T(n) = O(n (\log n)^2 \log\log n)$
29 ///
30 /// $M(n) = O(n \log n)$
31 ///
32 /// where $T$ is time, $M$ is additional memory, and $n$ is `s.len()`.
33 ///
34 /// # Examples
35 /// ```
36 /// use core::str::FromStr;
37 /// use malachite_base::vector::Vector;
38 /// use malachite_nz::integer_vector::IntegerVector;
39 ///
40 /// assert_eq!(
41 /// IntegerVector::from_str("(1, 2, 3)").unwrap().to_string(),
42 /// "(1, 2, 3)"
43 /// );
44 /// assert_eq!(IntegerVector::from_str("(5)").unwrap().to_string(), "(5)");
45 /// assert_eq!(IntegerVector::from_str("()").unwrap().dimension(), 0);
46 ///
47 /// // An element may be written as `Integer::from_str` accepts it.
48 /// assert_eq!(
49 /// IntegerVector::from_str("(-1, -0, +2)").unwrap().to_string(),
50 /// "(-1, 0, 2)"
51 /// );
52 /// assert_eq!(
53 /// IntegerVector::from_str("(007, +8)").unwrap().to_string(),
54 /// "(7, 8)"
55 /// );
56 ///
57 /// assert!(IntegerVector::from_str("").is_err());
58 /// assert!(IntegerVector::from_str("1, 2").is_err());
59 /// assert!(IntegerVector::from_str("(1,2)").is_err());
60 /// assert!(IntegerVector::from_str("( 1, 2 )").is_err());
61 /// assert!(IntegerVector::from_str("(1, )").is_err());
62 /// assert!(IntegerVector::from_str("(--1)").is_err());
63 /// ```
64 fn from_str(s: &str) -> Result<Self, ()> {
65 let inner = s
66 .strip_prefix('(')
67 .and_then(|s| s.strip_suffix(')'))
68 .ok_or(())?;
69 if inner.is_empty() {
70 return Ok(Self {
71 elements: Vec::new(),
72 });
73 }
74 Ok(Self {
75 elements: inner
76 .split(", ")
77 .map(Integer::from_str)
78 .collect::<Result<_, _>>()?,
79 })
80 }
81}