Add interpreter skeleton

app/src/main/java/com/annimon/hotarufx/lib/Context.java

@@ -0,0 +1,23 @@
+package com.annimon.hotarufx.lib;
+
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+public final class Context {
+
+    private final Map<String, Value> variables;
+    private final Map<String, Value> functions;
+
+    public Context() {
+        variables = new ConcurrentHashMap<>();
+        functions = new ConcurrentHashMap<>();
+    }
+
+    public Map<String, Value> variables() {
+        return variables;
+    }
+
+    public Map<String, Value> functions() {
+        return functions;
+    }
+}

app/src/main/java/com/annimon/hotarufx/parser/visitors/InterpreterVisitor.java

@@ -0,0 +1,49 @@
+package com.annimon.hotarufx.parser.visitors;
+
+import com.annimon.hotarufx.lib.Context;
+import com.annimon.hotarufx.lib.NumberValue;
+import com.annimon.hotarufx.lib.Value;
+import com.annimon.hotarufx.parser.ast.*;
+
+public class InterpreterVisitor implements ResultVisitor<Value, Context> {
+
+    @Override
+    public Value visit(AccessNode node, Context context) {
+        return NumberValue.ZERO;
+    }
+
+    @Override
+    public Value visit(AssignNode node, Context context) {
+        return NumberValue.ZERO;
+    }
+
+    @Override
+    public Value visit(BlockNode node, Context context) {
+        return NumberValue.ZERO;
+    }
+
+    @Override
+    public Value visit(FunctionNode node, Context context) {
+        return NumberValue.ZERO;
+    }
+
+    @Override
+    public Value visit(MapNode node, Context context) {
+        return NumberValue.ZERO;
+    }
+
+    @Override
+    public Value visit(UnaryNode node, Context context) {
+        return NumberValue.ZERO;
+    }
+
+    @Override
+    public Value visit(ValueNode node, Context context) {
+        return NumberValue.ZERO;
+    }
+
+    @Override
+    public Value visit(VariableNode node, Context context) {
+        return NumberValue.ZERO;
+    }
+}