nu_utils/quoting.rs
1use fancy_regex::Regex;
2use std::sync::LazyLock;
3
4// This hits, in order:
5// • Any character of []:`{}#'";()|$,.!?=
6// • Any digit (\d)
7// • Any whitespace (\s)
8// • Case-insensitive sign-insensitive float "keywords" inf, infinity and nan.
9static NEEDS_QUOTING_REGEX: LazyLock<Regex> = LazyLock::new(|| {
10 Regex::new(r#"[\[\]:`\{\}#'";\(\)\|\$,\.\d\s!?=]|(?i)^[+\-]?(inf(inity)?|nan)$"#)
11 .expect("internal error: NEEDS_QUOTING_REGEX didn't compile")
12});
13
14pub fn needs_quoting(string: &str) -> bool {
15 if string.is_empty() {
16 return true;
17 }
18 // These are case-sensitive keywords
19 match string {
20 // `true`/`false`/`null` are active keywords in JSON and NUON
21 // `&&` is denied by the nu parser for diagnostics reasons
22 // (https://github.com/nushell/nushell/pull/7241)
23 "true" | "false" | "null" | "&&" => return true,
24 _ => (),
25 };
26 // All other cases are handled here
27 NEEDS_QUOTING_REGEX.is_match(string).unwrap_or(false)
28}
29
30pub fn escape_quote_string(string: &str) -> String {
31 let mut output = String::with_capacity(string.len() + 2);
32 output.push('"');
33
34 for c in string.chars() {
35 if c == '"' || c == '\\' {
36 output.push('\\');
37 }
38 output.push(c);
39 }
40
41 output.push('"');
42 output
43}
44
45/// Returns a raw string representation if the string contains quotes or backslashes.
46/// Otherwise returns None (caller should use regular quoting or bare string).
47///
48/// Raw strings avoid escaping by using `r#'...'#` syntax with enough `#` characters
49/// to ensure the closing delimiter is unambiguous.
50///
51/// Note: Nushell requires at least one `#` in raw strings (i.e., `r#'...'#` not `r'...'`).
52pub fn as_raw_string(s: &str) -> Option<String> {
53 // Only use raw strings if they would avoid escaping
54 if !s.contains('"') && !s.contains('\\') {
55 return None;
56 }
57
58 // Find minimum # count needed for delimiter
59 // Nushell requires at least one #, so start at 1
60 // Need to avoid `'#...#` patterns in content that would close early
61 let mut hash_count = 1;
62 loop {
63 let closing = format!("'{}", "#".repeat(hash_count));
64 if !s.contains(&closing) {
65 break;
66 }
67 hash_count += 1;
68 }
69
70 let hashes = "#".repeat(hash_count);
71 Some(format!("r{hashes}'{s}'{hashes}"))
72}