Scrolling Window Pattern Matcher

This crate provides a generic pattern matcher that operates over a scrolling window (queue) of items. Patterns can be defined as sequences of values, functions, or a mix of both. When a pattern matches, an optional user-defined callback is invoked. The matcher supports optional deduplication of matches.

Features

Match patterns using values, functions, or both
Optional deduplication of matches
Support for overlapping matches
Callback invocation on match
No unnecessary trait bounds: PartialEq is only required for value-based patterns

Usage

use scrolling_window_pattern_matcher::{ScrollingWindowPatternMatcherRef, PatternElem};
let window = vec![&1, &2, &3, &4];
let patterns = vec![
    PatternElem::Value(1),
    PatternElem::Matcher(Box::new(|x: &i32| *x == 2)),
];
let matcher = ScrollingWindowPatternMatcherRef {
    window: std::collections::VecDeque::new(),
    max_pattern_len: 0,
    next_index: 0,
};
let matches = matcher.find_matches(&window, &patterns, false, None::<fn(usize, usize)>);
assert!(matches.contains(&(0, 0)));
assert!(matches.contains(&(1, 1)));

Function-only Patterns

use scrolling_window_pattern_matcher::ScrollingWindowPatternMatcherRef;
let window = vec![&1, &2, &3, &4];
let patterns_fn: Vec<Box<dyn Fn(&i32) -> bool>> = vec![
    Box::new(|x| *x == 1),
    Box::new(|x| *x == 4),
];
let matcher = ScrollingWindowPatternMatcherRef {
    window: std::collections::VecDeque::new(),
    max_pattern_len: 0,
    next_index: 0,
};
let matches = matcher.find_matches_functions_only(&window, &patterns_fn[..], false, None::<fn(usize, usize)>);
assert!(matches.contains(&(0, 0)));
assert!(matches.contains(&(1, 3)));

Deduplication and Overlapping Matches

Set deduplicate to true to avoid reporting the same match more than once.

Callback Example

use scrolling_window_pattern_matcher::{ScrollingWindowPatternMatcherRef, PatternElem};
let window = vec![&1, &2, &3];
let patterns = vec![PatternElem::Value(2)];
let matcher = ScrollingWindowPatternMatcherRef {
    window: std::collections::VecDeque::new(),
    max_pattern_len: 0,
    next_index: 0,
};
let mut called = false;
let _ = matcher.find_matches(&window, &patterns, false, Some(|pid, idx| {
    assert_eq!(pid, 0);
    assert_eq!(idx, 1);
    called = true;
}));
assert!(called);

Edge Cases

Empty window or patterns: returns no matches
Patterns can be all values, all functions, or mixed

API

find_matches: Use for value or mixed patterns (requires PartialEq for T)
find_matches_functions_only: Use for function-only patterns (no trait bound required)

See the test module for more comprehensive examples and edge cases.

scrolling_window_pattern_matcher 0.1.0