grammex

A generic graph rewriting engine with game-constraint semantics for procedural generation.

Live Demo

Features

• Graph rewriting: Define pattern->replacement rules for procedural generation
• Game constraints: Lock-and-key, reachability, cycle constraints built-in
• Multiple strategies: FirstMatch, WeightedRandom, Parallel (Markov Junior-style)
• Observable: Monitor rewriting progress via the RewriteObserver trait
• no_std compatible: Works in embedded and WASM environments
• Deterministic: Same seed produces same results

Quick Start

use grammex::*;

// Define your node and edge types
#[derive(Clone, PartialEq, Eq)]
struct Room(RoomKind);

#[derive(Clone, Copy, PartialEq, Eq, Debug)]
enum RoomKind { Start, Empty, Key, Lock, Boss }

impl NodeData for Room {
    type Kind = RoomKind;
    fn kind(&self) -> RoomKind { self.0 }
}

// Build a graph and rewriter
let mut graph = Graph::new();
let start = graph.add_node(Room(RoomKind::Start));

let config = RewriterConfig::new().max_steps(100);
let mut rewriter = Rewriter::new(graph, config);

// Add rules and constraints, then rewrite
let result = rewriter.rewrite(&mut rng)?;

Use Cases

• Dungeon/level generation with guaranteed completability
• Quest/mission structure generation
• Dialogue tree generation with narrative constraints
• Puzzle design (constraint-satisfying key/lock/switch placement)
• Multi-phase pipelines: structure -> rooms -> detail

License

Licensed under either of Apache License, Version 2.0 or MIT License at your option.