Kotoba Rewrite

Advanced graph rewriting engine for the Kotoba graph processing system. Implements formal graph transformation techniques including Double Pushout (DPO) rewriting and rule-based transformations.

🏗️ Features

Core Components

RewriteEngine: Main engine for applying graph transformations
RewriteRule: Pattern matching and transformation rules
Matcher: Graph pattern matching algorithms
Applier: Safe application of rewrite rules

Transformation Types

DPO (Double Pushout): Formal graph transformation method
Pattern Matching: Efficient subgraph isomorphism detection
Rule Application: Safe, transactional transformations
Validation: Pre/post-condition checking

🔧 Usage

use kotoba_rewrite::{RewriteEngine, RewriteRule};
use kotoba_graph::Graph;

// Create rewrite engine
let engine = RewriteEngine::new();

// Define transformation rule
let rule = RewriteRule {
    lhs: /* left-hand side pattern */,
    rhs: /* right-hand side pattern */,
    conditions: /* transformation conditions */,
};

// Apply transformation
let result = engine.apply_rule(&rule, &graph)?;

🧮 Algorithm

The rewrite engine uses the Double Pushout (DPO) approach:

L ←[m]→ K →[r]→ R
    ↓     ↓     ↓
L'←[m']→ K' →[r']→ R'

Where:

L: Left-hand side (pattern to match)
K: Interface (preserved elements)
R: Right-hand side (result pattern)
m, m': Match morphisms
r, r': Rule morphisms

📊 Performance

Efficient Matching: Optimized subgraph isomorphism algorithms
Transactional Safety: Atomic transformation operations
Memory Efficient: Minimal memory overhead for transformations
Composable Rules: Chain multiple transformations

🤝 Integration

Kotoba Rewrite integrates seamlessly with:

kotoba-graph: Core graph data structures
kotoba-core: Type system and IR definitions
kotoba-execution: Query execution with rewriting
kotoba-server: Graph transformation APIs

📄 License

MIT OR Apache-2.0

kotoba-rewrite 0.1.2