Validate PILES Notation

Parse and validate PILES notation strings for puzzle piece fusion groups.

When to Use

• Validating user-supplied PILES strings before passing to generate_puzzle()
• Debugging fusion group issues (wrong pieces merged, unexpected results)
• Explaining PILES notation to users in plain language
• Testing round-trip fidelity: parse -> groups -> serialize -> parse

Inputs

• Required: PILES notation string (e.g., "1-2-3,4-5")
• Optional: Puzzle result object (for adjacency validation and keyword resolution)
• Optional: Puzzle type (for keyword support like "center", "ring1", "R1")

Procedure