Module continuation 

Continuation state for development and fix iterations.

This module contains the ContinuationState structure and associated logic for managing continuation and retry attempts across development and fix phases.

Overview

The continuation system provides three key mechanisms:

1. Continuation Context and Budget System

When agent work is incomplete (status “partial” or “failed” for development, “issues_remain” or “failed” for fix), the system can trigger a continuation to let the agent continue work in the same iteration.

Budget limits:

• Development: max_continue_count attempts (default 3)
• Fix: max_fix_continue_count attempts (default 10)

Context tracking:

• Previous status, summary, files changed, next steps
• Continuation attempt counter
• Context file write/cleanup flags

Budget exhaustion triggers:

• When continuation_attempt >= max_continue_count, no more continuations allowed
• System proceeds to next phase even if work is incomplete

2. Retry Mechanisms

The system supports two types of retries when agent invocations fail:

XSD Retries

Triggered when agent output fails XML parsing or XSD validation:

• Budget: max_xsd_retry_count (default 10)
• Behavior: Re-invoke same agent with validation error feedback
• Session reuse: Preserves provider-side context for deterministic retries
• Exhaustion: Falls back to next agent in chain

Same-Agent Retries

Triggered for transient invocation failures (timeout, internal error):

• Budget: max_same_agent_retry_count (default 2)
• Behavior: Re-invoke same agent with reduced scope guidance
• Exhaustion: Falls back to next agent in chain

3. Loop Detection Mechanism

Prevents infinite tight loops by tracking consecutive identical effects:

Effect fingerprinting:

• Each effect execution is fingerprinted (e.g., “InvokeAgent(Developer, continuation=2)”)
• System tracks last_effect_kind and consecutive_same_effect_count

Detection threshold:

• max_consecutive_same_effect (default 100, see DEFAULT_LOOP_DETECTION_THRESHOLD)
• When threshold is exceeded, triggers loop recovery

Recovery behavior:

• Resets continuation state (including loop counters)
• Advances to next agent or phase to break the cycle

State Immutability

This is pure state code with no side effects:

• All methods return new ContinuationState instances
• No I/O operations (filesystem, environment, logging)
• No external dependencies beyond serde for serialization

Module Structure

• [state]: Core ContinuationState struct definition
• [budget]: Budget tracking and exhaustion checking
• [loop_detection]: Loop detection and effect fingerprinting

Structs

ContinuationState

Continuation state for development iterations.

Constants

DEFAULT_LOOP_DETECTION_THRESHOLD

Default threshold for consecutive identical effects before triggering loop recovery.