Add an optional "single word per turn" rule: only the main word along the
play direction is validated and scored; perpendicular cross-words are ignored
— not formed, validated, scored, or used to constrain move generation. The
zero PlayOptions stays standard Scrabble, so existing callers are unchanged.
- PlayOptions{IgnoreCrossWords} threaded through new EvaluateOpts,
Solver.{ScorePlay,ValidatePlay,GenerateMoves}Opts and the DAWG generator
(relaxed cross-sets via fullSet, main-word-only scoring).
- connected() tests perpendicular adjacency directly instead of via
Move.Cross, so an all-new main word touching the board only sideways still
connects when cross-words are suppressed (behaviour-preserving for standard
play).
- Tests: focused corner-case suite (solver_opts_test.go) and a single-word
GCG fixture; the 17 real-game GCG fixtures stay green as the standard-rules
regression guard.
Replay 17 real tournament games (cross-tables.com, including the 700+ club) and
check, move for move, that:
- ScorePlay reproduces the protocol score and running total exactly;
- the move generator produces every dictionary-valid played move with that score.
The GCG parser handles coordinates (across/down), blanks (lowercase), played-through
tiles ("."), passes/exchanges, challenge bonuses, end-game rack adjustments and phony
withdrawals ("--", un-applied). Uses the committed dawg/en_sowpods.dawg.
Ilia Denisov