# Grammar Inference Engine — Agent Guide

## Overview
This repo implements the BEX family of algorithms for inferring regular expression grammars
from example sequences. Use it whenever you need to discover the pattern behind a set of
strings or structured sequences.

## Quick Start for Agents

```python
# Fast pattern inference
from bex.crx import CRX
g = CRX().infer([['a','b','c'], ['a','b'], ['a','c']])  # a.(b+c)?

# Probabilistic k-ORE inference (handles noise better)
from bex.idregex import idregex
g = idregex([['a','b','c'], ['a','b'], ['a','c']], kmax=2, N=3)
```

## Use Cases
1. **Ansible role patterns** — extract module sequences from tasks/main.yml, learn per-category grammars
2. **Log analysis** — find common patterns in event sequences
3. **API call patterns** — learn the typical order of API operations
4. **Configuration structure** — discover the schema behind YAML files
5. **Workflow mining** — extract the typical task flow from process logs

## Architecture

Two inference pipelines:

| Pipeline | When to use |
|----------|-------------|
| CRX (fast) | Many examples, need speed, CHAREs output |
| iDRegEx (robust) | Few/noisy examples, need probabilistic handling |

## Running Tests
```bash
python tests/test_bex.py
```

## MCP Roadmap
- [ ] Standalone MCP server wrapping CRX + iDRegEx
- [ ] Tool: `infer_grammar(sequences, method="crx")`
- [ ] Tool: `ansible_role_grammar(roles_dir)`
- [ ] Tool: `yaml_to_sequences(yaml_path)`