Added chess.

chess/.project

@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>chess</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+	<filteredResources>
+		<filter>
+			<id>1745325861706</id>
+			<name></name>
+			<type>30</type>
+			<matcher>
+				<id>org.eclipse.core.resources.regexFilterMatcher</id>
+				<arguments>node_modules|\.git|__CREATED_BY_JAVA_LANGUAGE_SERVER__</arguments>
+			</matcher>
+		</filter>
+	</filteredResources>
+</projectDescription>

chess/.settings/org.eclipse.core.resources.prefs

@@ -0,0 +1,2 @@
+eclipse.preferences.version=1
+encoding/<project>=UTF-8

chess/.settings/org.eclipse.jdt.core.prefs

@@ -0,0 +1,11 @@
+eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=21
+org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
+org.eclipse.jdt.core.compiler.compliance=21
+org.eclipse.jdt.core.compiler.debug.lineNumber=generate
+org.eclipse.jdt.core.compiler.debug.localVariable=generate
+org.eclipse.jdt.core.compiler.debug.sourceFile=generate
+org.eclipse.jdt.core.compiler.problem.enablePreviewFeatures=disabled
+org.eclipse.jdt.core.compiler.problem.reportPreviewFeatures=warning
+org.eclipse.jdt.core.compiler.release=enabled
+org.eclipse.jdt.core.compiler.source=21

chess/src/chess/Main.java

@@ -0,0 +1,36 @@
+package chess;
+
+import java.awt.Color;
+import java.util.List;
+import java.util.Map;
+import javax.swing.Action;
+
+// A chessboard.
+class Board {
+    Map<Loc, Piece> board;
+}
+
+// A location on the board. Measured from top left corner.
+class Loc {
+    int x;
+    int y;
+
+    Loc(int x, int y) {
+        this.x = x;
+        this.y = y;
+    }
+}
+
+// The color a chess piece may assume.
+enum PieceCol {
+    BLACK,
+    WHITE;
+
+    Color mk() {
+        return this.equals(BLACK) ? new Color(0, 0, 0)
+                                  : new Color(255, 255, 255);
+    }
+}
+
+// The sort of piece.
+enum PieceType { PAWN, ROOK, KNIGHT, BISHOP, QUEEN, KING }