Implements three high-impact improvements from NCS-43:
1. Incremental L1 accumulator — L1 pre-activations are maintained
per-ply on a stack and updated by column-add/subtract when pieces
move, reducing L1 cost from O(768×1536) to O(pieces×1536) for root
init and O(changed_pieces×1536) per node. Column-major weight
transposition (l1WeightsT) makes each update sequential in memory.
2. Eval cache — a 256 K direct-mapped cache keyed by Zobrist hash
skips the L2-L5 forward pass for positions seen during quiescence,
where the same position often recurs across capture sequences.
3. Dynamic time allocation — NNUEBot now grants 1 500 ms in complex
positions (> 30 legal moves) and 500 ms in nearly-terminal ones
(< 5 moves), instead of a fixed 1 000 ms budget.
Accumulator hooks (initAccumulator, pushAccumulator, copyAccumulator,
evaluateAccumulator) are added to the Evaluation trait with no-op
defaults, so ClassicalBot and HybridBot are unaffected.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Summary
- Added fastparse_3:3.0.2 dependency to modules/io
- Implemented FenParserFastParse as a second alternative FEN parser using FastParse, with the same public API as
FenParser and FenParserCombinators
- Parsers are built bottom-up using (using P[Any]) Scala 3 syntax with NoWhitespace.* to prevent implicit whitespace
skipping; rank sum validation uses Pass/Fail inside .flatMap
- Added FenParserFastParseTest mirroring FenParserCombinatorsTest to prove behavioural equivalence across all three
implementations
Test plan
- All existing tests pass — FenParser, FenParserCombinators, and all other modules untouched
- FenParserFastParseTest covers all cases: valid FEN, invalid color, invalid castling, invalid board shapes, en
passant, rank overflow, round-trip via FenExporter
- All parser logic branches genuinely covered — known scoverage gap documented in docs/unresolved.md (FastParse inline
macro generates synthetic proxy methods that scoverage instruments but that never execute at runtime)
Co-authored-by: LQ63 <lkhermann@web.de>
Reviewed-on: #22
Reviewed-by: Janis <janis-e@gmx.de>
Co-authored-by: Leon Hermann <lq@blackhole.local>
Co-committed-by: Leon Hermann <lq@blackhole.local>
Summary
- Added scala-parser-combinators_3:2.4.0 dependency to modules/io
- Implemented FenParserCombinators as an alternative FEN parser using RegexParsers, with the same public API as the
existing FenParser
- Parsers are built bottom-up: piece characters → rank tokens → rank → board, composed with explicit field separators
into a full FEN parser
- Added FenParserCombinatorsTest mirroring the existing FenParserTest to prove behavioural equivalence
Test plan
- All existing tests pass — FenParser and all other modules untouched
- FenParserCombinatorsTest covers all cases: valid FEN, invalid color, invalid castling, invalid board shapes, en
passant, round-trip via FenExporter
- 100% line/branch/method coverage on FenParserCombinators
Co-authored-by: LQ63 <lkhermann@web.de>
Reviewed-on: #21
Reviewed-by: Janis <janis-e@gmx.de>
Co-authored-by: Leon Hermann <lq@blackhole.local>
Co-committed-by: Leon Hermann <lq@blackhole.local>
Summary
- Curried candidateMoves, legalMoves, and applyMove in the RuleSet trait to separate (context) as the world being
operated on from the computation parameter
- Updated DefaultRules overrides and all internal call sites
- Updated all external call sites: GameEngine, PgnParser, PgnExporter, ChessBoardView, and all affected tests
Test plan
- All existing tests pass (./gradlew build)
- No behaviour changes — pure style refactoring, existing test suite is the regression guard
Co-authored-by: LQ63 <lkhermann@web.de>
Reviewed-on: #18
Reviewed-by: Janis <janis-e@gmx.de>
Co-authored-by: Leon Hermann <lq@blackhole.local>
Co-committed-by: Leon Hermann <lq@blackhole.local>
Summary
- Implements the FIDE 50-move draw rule: a player may claim a draw if no pawn move or capture has occurred in the last
50 full moves (100 half-moves)
- Draw is not automatic — the eligible player must claim it via a TUI menu shown at the start of their turn
- halfMoveClock: Int is threaded through processMove and gameLoop; resets on pawn move, capture, or en passant;
increments on all other moves
Changes
- GameController.scala: extended MoveResult.Moved and MoveResult.MovedInCheck with newHalfMoveClock: Int; added
MoveResult.DrawClaimed; added halfMoveClock parameter to processMove and gameLoop; TUI menu shown when clock ≥ 100
- Main.scala: initial gameLoop call passes halfMoveClock = 0
- GameControllerTest.scala: updated all existing pattern matches; added 10 new tests covering clock reset, clock
increment, draw claim, and TUI menu behaviour
Test plan
- processMove: 'draw' with halfMoveClock = 100 → DrawClaimed
- processMove: 'draw' with halfMoveClock = 99 → InvalidFormat
- Pawn move / capture / en passant → clock resets to 0
- Quiet piece move → clock increments by 1
- MovedInCheck carries updated clock
- TUI menu appears when clock ≥ 100; option 1 claims draw, option 2 continues
- No TUI menu when clock < 100
- All 197 tests passing
Co-authored-by: LQ63 <lkhermann@web.de>
Reviewed-on: #9
Co-authored-by: Leon Hermann <lq@blackhole.local>
Co-committed-by: Leon Hermann <lq@blackhole.local>
Janis
Janis
TeamCity
lq64