Parse algebraic notation as input

chess/board.go

@@ -7,6 +7,7 @@ import (
 	"image/png"
 	"log"
 	"os"
+	"regexp"
 	"strings"
 
 	"golang.org/x/image/font"
@@ -253,6 +254,7 @@ func (b *Board) AlgebraicNotation() string {
 func (b *Board) Parse(pgn string) error {
 	var (
 		moves = strings.Split(strings.Trim(pgn, " "), " ")
+		re    = regexp.MustCompile(`[0-9]+\.`)
 		err   error
 	)
 
@@ -261,6 +263,10 @@ func (b *Board) Parse(pgn string) error {
 		if move == "" {
 			continue
 		}
+
+		// parse algebraic notation with numbers
+		move = re.ReplaceAllString(move, "")
+
 		if err = b.Move(move); err != nil {
 			return err
 		}

chess/board_test.go

@@ -511,6 +511,24 @@ func TestBoardCastle(t *testing.T) {
 	assertNoPiece(t, b, "e1")
 }
 
+func TestBoardParseAlgebraicNotation(t *testing.T) {
+	t.Parallel()
+
+	b := chess.NewBoard()
+
+	assertParse(t, b, "1.d4 d5 2.c4 e6")
+
+	assertPiece(t, b, "d4", chess.Pawn, chess.Light)
+	assertPiece(t, b, "d5", chess.Pawn, chess.Dark)
+	assertPiece(t, b, "c4", chess.Pawn, chess.Light)
+	assertPiece(t, b, "e6", chess.Pawn, chess.Dark)
+
+	assertNoPiece(t, b, "d2")
+	assertNoPiece(t, b, "d7")
+	assertNoPiece(t, b, "c2")
+	assertNoPiece(t, b, "e7")
+}
+
 func assertParse(t *testing.T, b *chess.Board, moves string) {
 	assert.NoError(t, b.Parse(moves))
 }