clap/
suggestions.rs

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1// Internal
2use crate::{app::App, fmt::Format};
3
4/// Produces a string from a given list of possible values which is similar to
5/// the passed in value `v` with a certain confidence.
6/// Thus in a list of possible values like ["foo", "bar"], the value "fop" will yield
7/// `Some("foo")`, whereas "blark" would yield `None`.
8#[cfg(feature = "suggestions")]
9#[cfg_attr(feature = "cargo-clippy", allow(clippy::needless_lifetimes))]
10pub fn did_you_mean<'a, T: ?Sized, I>(v: &str, possible_values: I) -> Option<&'a str>
11where
12    T: AsRef<str> + 'a,
13    I: IntoIterator<Item = &'a T>,
14{
15    let mut candidate: Option<(f64, &str)> = None;
16    for pv in possible_values {
17        let confidence = strsim::jaro_winkler(v, pv.as_ref());
18        if confidence > 0.8 && (candidate.is_none() || (candidate.as_ref().unwrap().0 < confidence))
19        {
20            candidate = Some((confidence, pv.as_ref()));
21        }
22    }
23    match candidate {
24        None => None,
25        Some((_, candidate)) => Some(candidate),
26    }
27}
28
29#[cfg(not(feature = "suggestions"))]
30pub fn did_you_mean<'a, T: ?Sized, I>(_: &str, _: I) -> Option<&'a str>
31where
32    T: AsRef<str> + 'a,
33    I: IntoIterator<Item = &'a T>,
34{
35    None
36}
37
38/// Returns a suffix that can be empty, or is the standard 'did you mean' phrase
39pub fn did_you_mean_flag_suffix<'z, T, I>(
40    arg: &str,
41    args_rest: &'z [&str],
42    longs: I,
43    subcommands: &'z [App],
44) -> (String, Option<&'z str>)
45where
46    T: AsRef<str> + 'z,
47    I: IntoIterator<Item = &'z T>,
48{
49    if let Some(candidate) = did_you_mean(arg, longs) {
50        let suffix = format!(
51            "\n\tDid you mean {}{}?",
52            Format::Good("--"),
53            Format::Good(candidate)
54        );
55        return (suffix, Some(candidate));
56    }
57
58    subcommands
59        .iter()
60        .filter_map(|subcommand| {
61            let opts = subcommand
62                .p
63                .flags
64                .iter()
65                .filter_map(|f| f.s.long)
66                .chain(subcommand.p.opts.iter().filter_map(|o| o.s.long));
67
68            let candidate = match did_you_mean(arg, opts) {
69                Some(candidate) => candidate,
70                None => return None,
71            };
72            let score = match args_rest.iter().position(|x| *x == subcommand.get_name()) {
73                Some(score) => score,
74                None => return None,
75            };
76
77            let suffix = format!(
78                "\n\tDid you mean to put '{}{}' after the subcommand '{}'?",
79                Format::Good("--"),
80                Format::Good(candidate),
81                Format::Good(subcommand.get_name())
82            );
83
84            Some((score, (suffix, Some(candidate))))
85        })
86        .min_by_key(|&(score, _)| score)
87        .map(|(_, suggestion)| suggestion)
88        .unwrap_or_else(|| (String::new(), None))
89}
90
91/// Returns a suffix that can be empty, or is the standard 'did you mean' phrase
92pub fn did_you_mean_value_suffix<'z, T, I>(arg: &str, values: I) -> (String, Option<&'z str>)
93where
94    T: AsRef<str> + 'z,
95    I: IntoIterator<Item = &'z T>,
96{
97    match did_you_mean(arg, values) {
98        Some(candidate) => {
99            let suffix = format!("\n\tDid you mean '{}'?", Format::Good(candidate));
100            (suffix, Some(candidate))
101        }
102        None => (String::new(), None),
103    }
104}
105
106#[cfg(all(test, features = "suggestions"))]
107mod test {
108    use super::*;
109
110    #[test]
111    fn possible_values_match() {
112        let p_vals = ["test", "possible", "values"];
113        assert_eq!(did_you_mean("tst", p_vals.iter()), Some("test"));
114    }
115
116    #[test]
117    fn possible_values_nomatch() {
118        let p_vals = ["test", "possible", "values"];
119        assert!(did_you_mean("hahaahahah", p_vals.iter()).is_none());
120    }
121
122    #[test]
123    fn suffix_long() {
124        let p_vals = ["test", "possible", "values"];
125        let suffix = "\n\tDid you mean \'--test\'?";
126        assert_eq!(
127            did_you_mean_flag_suffix("tst", p_vals.iter(), []),
128            (suffix, Some("test"))
129        );
130    }
131
132    #[test]
133    fn suffix_enum() {
134        let p_vals = ["test", "possible", "values"];
135        let suffix = "\n\tDid you mean \'test\'?";
136        assert_eq!(
137            did_you_mean_value_suffix("tst", p_vals.iter()),
138            (suffix, Some("test"))
139        );
140    }
141}
clap/suggestions.rs

clap/
suggestions.rs
