harper_core/patterns/
mod.rs

1//! [`Pattern`]s are one of the more powerful ways to query text inside Harper, especially for beginners.
2//!
3//! Through the [`PatternLinter`](crate::linting::PatternLinter) trait, they make it much easier to
4//! build Harper [rules](crate::linting::Linter).
5//!
6//! See the page about [`SequencePattern`] for a concrete example of their use.
7
8use crate::{Document, LSend, Span, Token};
9
10mod all;
11mod any_pattern;
12mod either_pattern;
13mod exact_phrase;
14mod implies_quantity;
15mod indefinite_article;
16mod inflection_of_be;
17mod invert;
18mod naive_pattern_group;
19mod nominal_phrase;
20mod pattern_map;
21mod repeating_pattern;
22mod sequence_pattern;
23mod similar_to_phrase;
24mod split_compound_word;
25mod whitespace_pattern;
26mod within_edit_distance;
27mod word;
28mod word_pattern_group;
29mod word_set;
30
31pub use all::All;
32pub use any_pattern::AnyPattern;
33use blanket::blanket;
34pub use either_pattern::EitherPattern;
35pub use exact_phrase::ExactPhrase;
36pub use implies_quantity::ImpliesQuantity;
37pub use indefinite_article::IndefiniteArticle;
38pub use inflection_of_be::InflectionOfBe;
39pub use invert::Invert;
40pub use naive_pattern_group::NaivePatternGroup;
41pub use nominal_phrase::NominalPhrase;
42pub use pattern_map::PatternMap;
43pub use repeating_pattern::RepeatingPattern;
44pub use sequence_pattern::SequencePattern;
45pub use similar_to_phrase::SimilarToPhrase;
46pub use split_compound_word::SplitCompoundWord;
47pub use whitespace_pattern::WhitespacePattern;
48pub use word::Word;
49pub use word_pattern_group::WordPatternGroup;
50pub use word_set::WordSet;
51
52#[cfg_attr(feature = "concurrent", blanket(derive(Arc)))]
53#[cfg_attr(not(feature = "concurrent"), blanket(derive(Rc, Arc)))]
54pub trait Pattern: LSend {
55    /// Check if the pattern matches at the start of the given token slice.
56    ///
57    /// Returns the length of the match if successful, or `None` if not.
58    fn matches(&self, tokens: &[Token], source: &[char]) -> Option<usize>;
59}
60
61pub trait PatternExt {
62    fn iter_matches(&self, tokens: &[Token], source: &[char]) -> impl Iterator<Item = Span>;
63
64    /// Search through all tokens to locate all non-overlapping pattern matches.
65    fn find_all_matches(&self, tokens: &[Token], source: &[char]) -> Vec<Span> {
66        self.iter_matches(tokens, source).collect()
67    }
68}
69
70impl<P> PatternExt for P
71where
72    P: Pattern + ?Sized,
73{
74    fn iter_matches(&self, tokens: &[Token], source: &[char]) -> impl Iterator<Item = Span> {
75        MatchIter::new(self, tokens, source)
76    }
77}
78
79struct MatchIter<'a, 'b, 'c, P: ?Sized> {
80    pattern: &'a P,
81    tokens: &'b [Token],
82    source: &'c [char],
83    index: usize,
84}
85impl<'a, 'b, 'c, P> MatchIter<'a, 'b, 'c, P>
86where
87    P: Pattern + ?Sized,
88{
89    fn new(pattern: &'a P, tokens: &'b [Token], source: &'c [char]) -> Self {
90        Self {
91            pattern,
92            tokens,
93            source,
94            index: 0,
95        }
96    }
97}
98impl<P> Iterator for MatchIter<'_, '_, '_, P>
99where
100    P: Pattern + ?Sized,
101{
102    type Item = Span;
103
104    fn next(&mut self) -> Option<Self::Item> {
105        while self.index < self.tokens.len() {
106            if let Some(len) = self
107                .pattern
108                .matches(&self.tokens[self.index..], self.source)
109            {
110                let span = Span::new_with_len(self.index, len);
111                self.index += len.max(1);
112                return Some(span);
113            } else {
114                self.index += 1;
115            }
116        }
117
118        None
119    }
120}
121
122pub trait OwnedPatternExt {
123    fn or(self, other: impl Pattern + 'static) -> EitherPattern;
124}
125
126impl<P> OwnedPatternExt for P
127where
128    P: Pattern + 'static,
129{
130    fn or(self, other: impl Pattern + 'static) -> EitherPattern {
131        EitherPattern::new(vec![Box::new(self), Box::new(other)])
132    }
133}
134
135/// A simpler version of the [`Pattern`] trait that only matches a single
136/// token.
137pub trait SingleTokenPattern: LSend {
138    fn matches_token(&self, token: &Token, source: &[char]) -> bool;
139}
140
141impl<S: SingleTokenPattern> Pattern for S {
142    fn matches(&self, tokens: &[Token], source: &[char]) -> Option<usize> {
143        if self.matches_token(tokens.first()?, source) {
144            Some(1)
145        } else {
146            None
147        }
148    }
149}
150
151impl<F: LSend + Fn(&Token, &[char]) -> bool> SingleTokenPattern for F {
152    fn matches_token(&self, token: &Token, source: &[char]) -> bool {
153        self(token, source)
154    }
155}
156
157pub trait DocPattern {
158    fn find_all_matches_in_doc(&self, document: &Document) -> Vec<Span>;
159}
160
161impl<P: PatternExt> DocPattern for P {
162    fn find_all_matches_in_doc(&self, document: &Document) -> Vec<Span> {
163        self.find_all_matches(document.get_tokens(), document.get_source())
164    }
165}
harper_core/patterns/mod.rs

harper_core/patterns/
mod.rs
