Struct LoopDetector 

pub struct LoopDetector { /* private fields */ }

Detects repeated action patterns in agent loops.

Three independent signals, each tracking consecutive repetitions:

Signal	Tracks	Catches
Exact	Identical signatures	Trivial loops (same tool, same args)
Category	Normalized signatures	Semantic loops (same intent, diff syntax)
Output	Identical tool output (by hash)	Stagnation (different tools, same result)

Usage:

let mut detector = LoopDetector::new(6);

// Per step: check action signatures
let sig = "bash:rg -n 'TODO' src/";
let cat = normalize_signature(sig);
match detector.check_with_category(sig, &cat) {
    LoopStatus::Abort(n) => { /* stop */ }
    LoopStatus::Warning(n) => { /* inject system message */ }
    LoopStatus::Ok => { /* proceed */ }
}

// Per action execution: check tool output
match detector.record_output("No matches found") {
    LoopStatus::Warning(n) => { /* nudge model */ }
    _ => {}
}

Implementations

impl LoopDetector

pub fn new(abort_threshold: usize) -> Self

Create detector. Warns at ⌈abort_threshold/2⌉, aborts at abort_threshold.

pub fn with_thresholds(warn_threshold: usize, abort_threshold: usize) -> Self

Create detector with explicit warn threshold.

pub fn check(&mut self, signature: &str) -> LoopStatus

Check action signature only (backward-compatible).

Uses signature as both exact match and category. For semantic loop detection, use [check_with_category] instead.

pub fn check_with_category( &mut self, signature: &str, category: &str, ) -> LoopStatus

Check action with separate exact signature and normalized category.

Returns the worst status across exact and category signals.

pub fn record_output(&mut self, output: &str) -> LoopStatus

Record a tool output and check for output stagnation.

Call after each action execution. Returns LoopStatus::Warning or LoopStatus::Abort if the same output has been seen too many consecutive times — the model is retrying a command that keeps giving the same result.

pub fn reset(&mut self)

Reset all detector state.

pub fn repeat_count(&self) -> usize

Current repeat count (max across all signals).

pub fn exact_count(&self) -> usize

Exact signature repeat count.

pub fn category_count(&self) -> usize

Normalized category repeat count.

pub fn output_count(&self) -> usize

Output stagnation repeat count.