Created IPopFrame

Author: LSafer

src/main/java/org/jamplate/glucose/instruction/memory/frame/IPopFrame.java

@@ -0,0 +1,100 @@
+/*
+ *	Copyright 2021 Cufy
+ *
+ *	Licensed under the Apache License, Version 2.0 (the "License");
+ *	you may not use this file except in compliance with the License.
+ *	You may obtain a copy of the License at
+ *
+ *	    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *	Unless required by applicable law or agreed to in writing, software
+ *	distributed under the License is distributed on an "AS IS" BASIS,
+ *	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *	See the License for the specific language governing permissions and
+ *	limitations under the License.
+ */
+package org.jamplate.glucose.instruction.memory.frame;
+
+import org.jamplate.memory.Memory;
+import org.jamplate.model.Environment;
+import org.jamplate.model.Instruction;
+import org.jamplate.model.Tree;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.Objects;
+
+/**
+ * An instruction that pops the last frame.
+ * <br><br>
+ * Memory Visualization:
+ * <pre>
+ *     ...[...][...]
+ *     ...[...]
+ * </pre>
+ *
+ * @author LSafer
+ * @version 0.3.0
+ * @since 0.3.0 ~2021.07.11
+ */
+public class IPopFrame implements Instruction {
+	/**
+	 * An instance of this instruction.
+	 *
+	 * @since 0.3.0 ~2021.07.11
+	 */
+	@NotNull
+	public static final IPopFrame INSTANCE = new IPopFrame();
+
+	@SuppressWarnings("JavaDoc")
+	private static final long serialVersionUID = 849942142548986258L;
+
+	/**
+	 * A reference of this instruction in the source code.
+	 *
+	 * @since 0.3.0 ~2021.07.11
+	 */
+	@Nullable
+	protected final Tree tree;
+
+	/**
+	 * Construct a new instruction that pops the last frame.
+	 *
+	 * @since 0.3.0 ~2021.07.11
+	 */
+	public IPopFrame() {
+		this.tree = null;
+	}
+
+	/**
+	 * Construct a new instruction that pops the last frame.
+	 *
+	 * @param tree a reference for the constructed instruction in the source code.
+	 * @throws NullPointerException if the given {@code tree} is null.
+	 * @since 0.3.0 ~2021.07.11
+	 */
+	public IPopFrame(@NotNull Tree tree) {
+		Objects.requireNonNull(tree, "tree");
+		this.tree = tree;
+	}
+
+	@Override
+	public void exec(@NotNull Environment environment, @NotNull Memory memory) {
+		Objects.requireNonNull(environment, "environment");
+		Objects.requireNonNull(memory, "memory");
+
+		memory.popFrame();
+	}
+
+	@Nullable
+	@Override
+	public Tree getTree() {
+		return this.tree;
+	}
+
+	@NotNull
+	@Override
+	public Instruction optimize(int mode) {
+		return mode < 0 ? IPopFrame.INSTANCE : new IPopFrame(new Tree(this.tree));
+	}
+}