oak_core/lexer/
cache.rs

1use crate::{
2    Language,
3    lexer::{LexOutput, Token},
4};
5
6/// Cache trait for lexical results.
7///
8/// This trait defines the interface for caching and accessing lexical analysis results.
9/// It provides methods for storing and retrieving token information from previous
10/// lexical analysis operations.
11#[allow(unused_variables)]
12pub trait LexerCache<L: Language> {
13    /// Sets the lexed output in the cache.
14    ///
15    /// # Arguments
16    ///
17    /// * `output` - The output from lexical analysis, including tokens and diagnostics
18    fn set_lex_output(&mut self, output: LexOutput<L>);
19
20    /// Gets a token from the cache by index.
21    ///
22    /// # Arguments
23    ///
24    /// * `index` - The index of the token to retrieve
25    ///
26    /// # Returns
27    ///
28    /// An `Option<Token<L::TokenType>>` containing the token if it exists,
29    /// or `None` if the index is out of bounds or no tokens are cached
30    fn get_token(&self, index: usize) -> Option<Token<L::TokenType>>;
31
32    /// Gets the total number of tokens in the cache.
33    ///
34    /// # Returns
35    ///
36    /// The number of cached tokens, or 0 if no tokens are cached
37    fn count_tokens(&self) -> usize;
38
39    /// Checks if the cache contains any tokens.
40    ///
41    /// # Returns
42    ///
43    /// `true` if the cache contains tokens, `false` otherwise
44    fn has_tokens(&self) -> bool;
45
46    /// Gets all cached tokens as a slice.
47    ///
48    /// # Returns
49    ///
50    /// An optional slice of tokens if available.
51    fn get_tokens(&self) -> Option<&[Token<L::TokenType>]> {
52        None
53    }
54}
55
56impl<'a, L: Language, C: LexerCache<L> + ?Sized> LexerCache<L> for &'a mut C {
57    fn set_lex_output(&mut self, output: LexOutput<L>) {
58        (**self).set_lex_output(output)
59    }
60
61    fn get_token(&self, index: usize) -> Option<Token<L::TokenType>> {
62        (**self).get_token(index)
63    }
64
65    fn count_tokens(&self) -> usize {
66        (**self).count_tokens()
67    }
68
69    fn has_tokens(&self) -> bool {
70        (**self).has_tokens()
71    }
72
73    fn get_tokens(&self) -> Option<&[Token<L::TokenType>]> {
74        (**self).get_tokens()
75    }
76}
77
78/// A no-op implementation of `LexerCache`.
79#[derive(Debug, Clone, Copy, Default)]
80pub struct NoLexerCache;
81
82impl<L: Language> LexerCache<L> for NoLexerCache {
83    fn set_lex_output(&mut self, _output: LexOutput<L>) {}
84
85    fn get_token(&self, _index: usize) -> Option<Token<L::TokenType>> {
86        None
87    }
88
89    fn count_tokens(&self) -> usize {
90        0
91    }
92
93    fn has_tokens(&self) -> bool {
94        false
95    }
96}
oak_core/lexer/cache.rs

oak_core/lexer/
cache.rs
