fix typos

src/movegen.h

@@ -28,7 +28,7 @@ namespace Stockfish {
 class Position;
 
 enum GenType {
-  /// yjf2002ghty: I think it's better to add some explanations here so that new developers can understand what these means, as some of the terms connot be found in chessprogramming wiki. I'm not sure if my explanations are correct. If there are anything wrong, please point it out.
+  /// yjf2002ghty: I think it's better to add some explanations here so that new developers can understand what these means, as some of the terms cannot be found in chessprogramming wiki. I'm not sure if my explanations are correct. If there are anything wrong, please point it out.
 
   //Moves that a piece is removed from the board as part of the completion of the move
   CAPTURES,

src/parser.cpp

@@ -249,7 +249,7 @@ namespace {
                 }
                 else if (ch == ',' || ch == ')')
                 {
-                    if (RankNum == 0)  // Here if RankNum==0 then it means either user delcared a 0 as rank, or no rank number delcared at all
+                    if (RankNum == 0)  // Here if RankNum==0 then it means either user declared a 0 as rank, or no rank number declared at all
                     {
                         std::cerr << "At char " << i << " of PieceTypeBitboardGroup declaration: Illegal rank number: " << RankNum << std::endl;
                         return false;

src/position.h

@@ -503,7 +503,7 @@ inline Bitboard Position::promotion_zone(Piece p) const {
 
 inline Square Position::promotion_square(Color c, Square s) const {
   assert(var != nullptr);
-  /// yjf2002ghty: I'm not clear what Square s means, whether it refers to a square of a piece or it can refer to any square. I assume it means a square of a piece which can excute piece_on(s)
+  /// yjf2002ghty: I'm not clear what Square s means, whether it refers to a square of a piece or it can refer to any square. I assume it means a square of a piece which can execute piece_on(s)
   Piece p = piece_on(s);
   Bitboard b = ((p == NO_PIECE) ? Bitboard(0) : promotion_zone(p)) & forward_file_bb(c, s) & board_bb();
   return !b ? SQ_NONE : c == WHITE ? lsb(b) : msb(b);