Clean up duplicated functions

src/main/scala/File.scala

@@ -4,7 +4,7 @@ opaque type File = Int
 object File:
 
   extension (a: File)
-    inline def index: Int = a
+    // inline def index: Int = a
     inline def value: Int = a
 
     inline infix def >(inline o: File): Boolean  = a > o

src/main/scala/Hash.scala

@@ -82,7 +82,7 @@ object Hash extends OpaqueInt[Hash]:
       else hpieces
 
     val hep = situation.enPassantSquare.fold(hcastling): square =>
-      hcastling ^ table.enPassantMasks(square.file.index)
+      hcastling ^ table.enPassantMasks(square.file.value)
 
     // Hash in special three-check data.
     val hchecks = board.variant match

src/main/scala/Rank.scala

@@ -5,7 +5,6 @@ object Rank:
   extension (a: Rank)
 
     inline def value: Int = a
-    inline def index: Int = a
 
     inline infix def >(inline o: Rank): Boolean  = a > o
     inline infix def <(inline o: Rank): Boolean  = a < o

src/main/scala/Situation.scala

@@ -185,13 +185,13 @@ case class Situation(board: Board, color: Color):
 
     val s2: List[Move] = for
       to   <- singleMoves & mask
-      from <- Square.at(to.value + (if isWhiteTurn then -8 else 8)).toList
+      from <- Square(to.value + (if isWhiteTurn then -8 else 8)).toList
       move <- genPawnMoves(from, to, false)
     yield move
 
     val s3: List[Move] = for
       to   <- doubleMoves & mask
-      from <- Square.at(to.value + (if isWhiteTurn then -16 else 16))
+      from <- Square(to.value + (if isWhiteTurn then -16 else 16))
       move <- normalMove(from, to, Pawn, false)
     yield move
 

src/main/scala/Square.scala

@@ -64,10 +64,11 @@ object Square:
   end extension
 
   inline def apply(inline file: File, inline rank: Rank): Square = file.value + 8 * rank.value
+
   inline def apply(index: Int): Option[Square]  = Option.when(0 <= index && index < 64)(index)
   private[chess] def unsafe(index: Int): Square = index
 
-  inline def at(index: Int): Option[Square] = Option.when(0 <= index && index < 64)(index)
+  // inline def at(index: Int): Option[Square] = Option.when(0 <= index && index < 64)(index)
 
   inline def at(x: Int, y: Int): Option[Square] = Option.when(0 <= x && x < 8 && 0 <= y && y < 8)(x + 8 * y)
 

src/main/scala/bitboard/Bitboard.scala

@@ -87,10 +87,10 @@ object Bitboard:
     def count: Int = java.lang.Long.bitCount(a)
 
     // the first non empty square (the least significant bit/ the rightmost bit)
-    def first: Option[Square] = Square.at(java.lang.Long.numberOfTrailingZeros(a))
+    def first: Option[Square] = Square(java.lang.Long.numberOfTrailingZeros(a))
 
     // the last non empty square (the most significant bit / the leftmost bit)
-    def last: Option[Square] = Square.at(63 - java.lang.Long.numberOfLeadingZeros(a))
+    def last: Option[Square] = Square(63 - java.lang.Long.numberOfLeadingZeros(a))
 
     // remove the first non empty position
     def removeFirst: Bitboard = a & (a - 1L)

src/main/scala/format/FenWriter.scala

@@ -12,7 +12,7 @@ import ornicar.scalalib.zeros.given
   */
 trait FenWriter:
 
-  private given Ordering[File] = Ordering.by[File, Int](_.index)
+  private given Ordering[File] = Ordering.by[File, Int](_.value)
   given Ordering[Square]       = Ordering.by[Square, File](_.file)
 
   def write(situation: Situation): EpdFen = write(Situation.AndFullMoveNumber(situation, FullMoveNumber(1)))

src/main/scala/format/UciCharPair.scala

@@ -49,7 +49,7 @@ object UciCharPair:
     val promotion2charMap: Map[(File, PromotableRole), Char] = for
       (role, index) <- Role.allPromotable.zipWithIndex.toMap
       file          <- File.all
-    yield (file, role) -> (charShift + square2charMap.size + index * 8 + file.index).toChar
+    yield (file, role) -> (charShift + square2charMap.size + index * 8 + file.value).toChar
 
     lazy val char2promotionMap: Map[Char, (File, PromotableRole)] =
       promotion2charMap.map(_.swap)

src/main/scala/format/pgn/parsingModel.scala

@@ -40,8 +40,8 @@ case class Std(
     situation.board
       .byPiece(situation.color - role)
       .first: square =>
-        if compare(file, square.file.index) &&
-          compare(rank, square.rank.index)
+        if compare(file, square.file.value) &&
+          compare(rank, square.rank.value)
         then situation.generateMovesAt(square).find(_.dest == dest)
         else None
       .toRight(ErrorStr(s"No move found: $this\n$situation"))

src/main/scala/variant/Horde.scala

@@ -26,7 +26,7 @@ case object Horde
     yield (Square(x, y) -> White.pawn)
     val frontPawns  = List(Square.B5, Square.C5, Square.F5, Square.G5).map { _ -> White.pawn }
     val blackPawns  = File.all.map { Square(_, Rank.Seventh) -> Black.pawn }
-    val blackPieces = File.all.map { x => Square(x, Rank.Eighth) -> (Black - backRank(x.index)) }
+    val blackPieces = File.all.map { x => Square(x, Rank.Eighth) -> (Black - backRank(x.value)) }
     whitePawnsHorde ++ frontPawns ++ blackPawns ++ blackPieces toMap
 
   override val castles = Castles("kq")