morpion-solitaire-record (msr)

A small, self-describing interchange format for Morpion Solitaire games — the move list plus optional provenance (who/what/when produced it, how hard, and a few derived facts) — with a reference reader, writer and validator.

The crate is published as morpion-solitaire-record and imported as msr:

[dependencies]
morpion-solitaire-record = "0.1"

MSRV: Rust 1.74+ (verified in CI). No unsafe (#![forbid(unsafe_code)]).

use msr::{decode, encode, validate, Record, RecordMove, Variant, Direction};

// Read either form (compact `MS1:` envelope or plain JSON):
let record = decode(text)?;

// Verify it is a legal game, independently of any solver:
validate(&record)?;

// Write it back out (compact, or `encode_json` for the readable form):
let compact = encode(&record)?;

Why MSR (and not Pentasol)

The community Pentasol text format covers only the 5T/5D variants and stores the moves alone. MSR:

• is lossless for all four variants (4T / 4D / 5T / 5D);
• carries provenance metadata (producer, author, method, seed, timestamps, search effort, free-form tags) so a file is meaningful on its own;
• offers a compact form (MS1: = Base64 of DEFLATE-compressed JSON) and a human-readable JSON form, both carrying the same data;
• ships a reference validator so any tool can check a record is legal.

A Pentasol bridge is provided for migration.

Tooling

This crate is the library; the morpion-solitaire application — a desktop/web GUI and a headless CLI — is the reference tool built on it. The CLI reads any MSR (compact or JSON) or Pentasol file and emits it in any format with convert --to ascii|msr|json|pentasol|svg|png (default ascii):

morpion-solitaire convert game.psol --variant 5T --to msr -o game.msr  # Pentasol → MSR
morpion-solitaire convert game.msr  --to json                          # MSR → readable JSON
morpion-solitaire convert game.msr  --to pentasol                      # MSR → legacy Pentasol (5T/5D)
morpion-solitaire convert game.msr  --to png -o game.png               # rendered board image
morpion-solitaire convert game.msr                                     # ASCII board on the terminal

morpion-solitaire replay game.msr                                      # metadata + board + verdict
morpion-solitaire replay game.msr -q                                   # just the legality verdict

The SVG and PNG embed the full record (PNG in a tEXt chunk, SVG in a <metadata> element), so a rendered image is itself a loadable save — the GUI reads them back (and accepts drag-and-dropped .png/.svg/.msr/.json/.psol files). replay re-derives the game move by move, so it doubles as a validator (non-zero exit on an illegal game). The GUI additionally searches for record games (NRPA, large-neighbourhood perturbation, exhaustive) and runs in the browser via WebAssembly.

Specification

The normative definition is the MSR 0.1 specification and JSON Schema in the docs/spec directory of the repository. This crate is the reference implementation.

License

Licensed under either of MIT or Apache-2.0 at your option. (The Morpion Solitaire application that uses this crate is licensed separately under GPL-3.0-or-later.)