From f1cb08b94ccbda99f25c0e065fd6e28388d317d0 Mon Sep 17 00:00:00 2001
From: Barak Michener <me@barakmich.com>
Date: Wed, 13 Jul 2022 12:13:23 -0700
Subject: [PATCH 1/2] feat: Expose getPiece as GetPiece

Currently, there's no way to build a *chess.Piece from the constituent
PieceType and Color... it's useful, as it exists in the package already,
so it seems nice to make this helper function public.
---
 board.go  |  2 +-
 engine.go | 10 +++++-----
 piece.go  |  2 +-
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/board.go b/board.go
index 209084f..a0e9fcb 100644
--- a/board.go
+++ b/board.go
@@ -233,7 +233,7 @@ func (b *Board) update(m *Move) {
 	}
 	// check promotion
 	if m.promo != NoPieceType {
-		newPiece := getPiece(m.promo, p1.Color())
+		newPiece := GetPiece(m.promo, p1.Color())
 		// remove pawn
 		bbPawn := b.bbForPiece(p1)
 		b.setBBForPiece(p1, bbPawn & ^s2BB)
diff --git a/engine.go b/engine.go
index 8271031..f96d6cc 100644
--- a/engine.go
+++ b/engine.go
@@ -133,25 +133,25 @@ func squaresAreAttacked(pos *Position, sqs ...Square) bool {
 			continue
 		}
 		// check queen attack vector
-		queenBB := pos.board.bbForPiece(getPiece(Queen, otherColor))
+		queenBB := pos.board.bbForPiece(GetPiece(Queen, otherColor))
 		bb := (diaAttack(occ, sq) | hvAttack(occ, sq)) & queenBB
 		if bb != 0 {
 			return true
 		}
 		// check rook attack vector
-		rookBB := pos.board.bbForPiece(getPiece(Rook, otherColor))
+		rookBB := pos.board.bbForPiece(GetPiece(Rook, otherColor))
 		bb = hvAttack(occ, sq) & rookBB
 		if bb != 0 {
 			return true
 		}
 		// check bishop attack vector
-		bishopBB := pos.board.bbForPiece(getPiece(Bishop, otherColor))
+		bishopBB := pos.board.bbForPiece(GetPiece(Bishop, otherColor))
 		bb = diaAttack(occ, sq) & bishopBB
 		if bb != 0 {
 			return true
 		}
 		// check knight attack vector
-		knightBB := pos.board.bbForPiece(getPiece(Knight, otherColor))
+		knightBB := pos.board.bbForPiece(GetPiece(Knight, otherColor))
 		bb = bbKnightMoves[sq] & knightBB
 		if bb != 0 {
 			return true
@@ -173,7 +173,7 @@ func squaresAreAttacked(pos *Position, sqs ...Square) bool {
 			}
 		}
 		// check king attack vector
-		kingBB := pos.board.bbForPiece(getPiece(King, otherColor))
+		kingBB := pos.board.bbForPiece(GetPiece(King, otherColor))
 		bb = bbKingMoves[sq] & kingBB
 		if bb != 0 {
 			return true
diff --git a/piece.go b/piece.go
index 975b67a..d79f987 100644
--- a/piece.go
+++ b/piece.go
@@ -128,7 +128,7 @@ var (
 	}
 )
 
-func getPiece(t PieceType, c Color) Piece {
+func GetPiece(t PieceType, c Color) Piece {
 	for _, p := range allPieces {
 		if p.Color() == c && p.Type() == t {
 			return p

From bba806239b8b6a596345c306098f8f23b9326810 Mon Sep 17 00:00:00 2001
From: Logan Spears <logan@logan-desktop.lan>
Date: Sun, 7 Aug 2022 19:36:38 -0700
Subject: [PATCH 2/2] renamed GetPiece to NewPiece and added comments

---
 board.go  |  2 +-
 engine.go | 10 +++++-----
 piece.go  |  4 +++-
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/board.go b/board.go
index a0e9fcb..a61718d 100644
--- a/board.go
+++ b/board.go
@@ -233,7 +233,7 @@ func (b *Board) update(m *Move) {
 	}
 	// check promotion
 	if m.promo != NoPieceType {
-		newPiece := GetPiece(m.promo, p1.Color())
+		newPiece := NewPiece(m.promo, p1.Color())
 		// remove pawn
 		bbPawn := b.bbForPiece(p1)
 		b.setBBForPiece(p1, bbPawn & ^s2BB)
diff --git a/engine.go b/engine.go
index f96d6cc..ff49d10 100644
--- a/engine.go
+++ b/engine.go
@@ -133,25 +133,25 @@ func squaresAreAttacked(pos *Position, sqs ...Square) bool {
 			continue
 		}
 		// check queen attack vector
-		queenBB := pos.board.bbForPiece(GetPiece(Queen, otherColor))
+		queenBB := pos.board.bbForPiece(NewPiece(Queen, otherColor))
 		bb := (diaAttack(occ, sq) | hvAttack(occ, sq)) & queenBB
 		if bb != 0 {
 			return true
 		}
 		// check rook attack vector
-		rookBB := pos.board.bbForPiece(GetPiece(Rook, otherColor))
+		rookBB := pos.board.bbForPiece(NewPiece(Rook, otherColor))
 		bb = hvAttack(occ, sq) & rookBB
 		if bb != 0 {
 			return true
 		}
 		// check bishop attack vector
-		bishopBB := pos.board.bbForPiece(GetPiece(Bishop, otherColor))
+		bishopBB := pos.board.bbForPiece(NewPiece(Bishop, otherColor))
 		bb = diaAttack(occ, sq) & bishopBB
 		if bb != 0 {
 			return true
 		}
 		// check knight attack vector
-		knightBB := pos.board.bbForPiece(GetPiece(Knight, otherColor))
+		knightBB := pos.board.bbForPiece(NewPiece(Knight, otherColor))
 		bb = bbKnightMoves[sq] & knightBB
 		if bb != 0 {
 			return true
@@ -173,7 +173,7 @@ func squaresAreAttacked(pos *Position, sqs ...Square) bool {
 			}
 		}
 		// check king attack vector
-		kingBB := pos.board.bbForPiece(GetPiece(King, otherColor))
+		kingBB := pos.board.bbForPiece(NewPiece(King, otherColor))
 		bb = bbKingMoves[sq] & kingBB
 		if bb != 0 {
 			return true
diff --git a/piece.go b/piece.go
index d79f987..1063ba1 100644
--- a/piece.go
+++ b/piece.go
@@ -128,7 +128,9 @@ var (
 	}
 )
 
-func GetPiece(t PieceType, c Color) Piece {
+// NewPiece returns the piece matching the PieceType and Color.
+// NoPiece is returned if the PieceType or Color isn't valid.
+func NewPiece(t PieceType, c Color) Piece {
 	for _, p := range allPieces {
 		if p.Color() == c && p.Type() == t {
 			return p