Prioritize computing nodes with few children, prioritize takes, move 1 second earlier to avoid exceeding the move time

lib/classes/best_move_searcher.dart

@@ -98,10 +98,15 @@ class BestMoveSearcher {
     return value;
   }
 
-  static int getPositionBasePriority(Position position, int value, Iterable<(String, Position)> legalMoves, int depth) =>
-    legalMoves.isEmpty
-      ? Numbers.maxInteger
-      : 0;
+  static int getPositionBasePriority(Position position, int value, Iterable<(String, Position)> legalMoves, int depth) {
+    if (legalMoves.isEmpty) {
+      return Numbers.maxInteger;
+    }
+    if (legalMoves.length < 10) {
+      return (-2520 / legalMoves.length).toInt() >> 2;
+    }
+    return 0;
+  }
 
   Future<String?> search(Position position, int? moveTime) async {
     _isRunning = true;
@@ -114,7 +119,7 @@ class BestMoveSearcher {
     while (!_isStopped &&  positionTree.priority < Numbers.maxInteger) {
       positionTree.computeStep();
       time = DateTime.now().millisecondsSinceEpoch - startTime;
-      if (null != moveTime && time >= moveTime) {
+      if (null != moveTime && time >= moveTime - 1000) {
         _isStopped = true;
       }
       if (positionTree.childrenByValue.isNotEmpty || bestValue != positionTree.value) {

lib/classes/position.dart

@@ -363,4 +363,11 @@ class Position {
     move.length > 4 ? move.substring(4).toLowerCase() : null,
   );
 
+  static bool isTake(Position position, String move) {
+    final (int from, int to, String? promotingPiece) = moveStringToIndices(move);
+    return
+      (position.board[to] != Piece.emptySquare) ||
+      (position.enPassantTargetSquare == to && (position.board[from] == Piece.whitePawn || position.board[from] == Piece.blackPawn));
+  }
+
 }

lib/data_structures/position_tree_node.dart

@@ -63,27 +63,30 @@ class PositionTreeNode {
       _computeChildren();
       return;
     }
-    final PositionTreeNode firstChild = children.first;
-    final int initialFirstChildNodeCount = firstChild.nodeCount;
-    firstChild.computeStep();
-    children.updateElement(firstChild.move);
-    childrenByValue.updateElement(firstChild.move);
-    nodeCount += firstChild.nodeCount - initialFirstChildNodeCount;
-    if (firstChild.depth + 1 > depth) {
-      depth = firstChild.depth + 1;
+    final PositionTreeNode computedChild = children.first;
+    final int initialFirstChildNodeCount = computedChild.nodeCount;
+    computedChild.computeStep();
+    children.updateElement(computedChild.move);
+    childrenByValue.updateElement(computedChild.move);
+    nodeCount += computedChild.nodeCount - initialFirstChildNodeCount;
+    if (computedChild.depth + 1 > depth) {
+      depth = computedChild.depth + 1;
     }
-    priority = (children.first.priority == Numbers.maxInteger) ? children.first.priority : children.first.priority + 1;
+    priority = (children.first.priority == Numbers.maxInteger) ? children.first.priority : children.first.priority + 100;
     value = childrenByValue.first.value;
   }
 
   void _computeChildren() {
     for (final (String, Position) move in legalMoves) {
       final PositionTreeNode positionTreeNode = PositionTreeNode.fromPosition(move.$2, move.$1);
+      if (Position.isTake(position, move.$1)) {
+        positionTreeNode.priority -= 200;
+      }
       children.add(positionTreeNode);
       childrenByValue.add(positionTreeNode);
     }
     nodeCount = legalMoves.length;
-    priority = (children.first.priority == Numbers.maxInteger) ? children.first.priority : children.first.priority + 1;
+    priority = (children.first.priority == Numbers.maxInteger) ? children.first.priority : children.first.priority + 100;
     depth = 1;
     value = childrenByValue.first.value;
   }

lib/functions/_partials/legal_moves_black.dart

@@ -203,7 +203,7 @@ class _LegalMovesBlack {
     // up
     bool hasEncounteredPiece = false;
     int j = i-8;
-    while (!hasEncounteredPiece && j > 0) {
+    while (!hasEncounteredPiece && j >= 0) {
       if (Piece.emptySquare == position.board[j]) {
         yield ("${Position.squareIndexToString(i)}${Position.squareIndexToString(j)}", Position.from(position)..playMoveIndices(i, j));
       } else {

lib/functions/_partials/legal_moves_white.dart

@@ -203,7 +203,7 @@ class _LegalMovesWhite {
     // up
     bool hasEncounteredPiece = false;
     int j = i-8;
-    while (!hasEncounteredPiece && j > 0) {
+    while (!hasEncounteredPiece && j >= 0) {
       if (Piece.emptySquare == position.board[j]) {
         yield ("${Position.squareIndexToString(i)}${Position.squareIndexToString(j)}", Position.from(position)..playMoveIndices(i, j));
       } else {

lib/omnichess.dart

@@ -110,26 +110,26 @@ class Omnichess {
   }
 
   void loop() async {
-    final DateTime now = DateTime.now();
-    final String logName = "${now.year}"
-      "${now.month.toString().padLeft(2, "0")}"
-      "${now.day.toString().padLeft(2, "0")}"
-      "-"
-      "${now.hour.toString().padLeft(2, "0")}"
-      "${now.minute.toString().padLeft(2, "0")}"
-      "${now.second.toString().padLeft(2, "0")}"
-      "${now.millisecond.toString().padLeft(3, "0")}"
-      ".log";
-    final File log = File("logs/$logName");
-    if (!log.existsSync()) {
-      log.createSync();
-    }
+    // final DateTime now = DateTime.now();
+    // final String logName = "${now.year}"
+    //   "${now.month.toString().padLeft(2, "0")}"
+    //   "${now.day.toString().padLeft(2, "0")}"
+    //   "-"
+    //   "${now.hour.toString().padLeft(2, "0")}"
+    //   "${now.minute.toString().padLeft(2, "0")}"
+    //   "${now.second.toString().padLeft(2, "0")}"
+    //   "${now.millisecond.toString().padLeft(3, "0")}"
+    //   ".log";
+    // final File log = File("logs/$logName");
+    // if (!log.existsSync()) {
+    //   log.createSync();
+    // }
     late StreamSubscription<String> inputSubscription;
     inputSubscription = stdin
       .transform(utf8.decoder)
       .transform(LineSplitter())
       .listen((String line) async {
-        log.writeAsStringSync("$line\n", mode: FileMode.append);
+        // log.writeAsStringSync("$line\n", mode: FileMode.append);
         final String input = line.trim();
         final bool keepGoing = await elaborate(input);
         if (!keepGoing) {