Optimized invoker meta data and default memory.

- created class `Meta`.

- added `Meta.Memory`.
- added `Meta.OUTPUT`.
- added `Meta.PROJECT`.

- added `Address.OUTPUT`.

- updated `Jamplate.execute(...)`

- tests

Author: LSafer

src/main/java/org/jamplate/impl/Address.java

@@ -74,6 +74,14 @@ public final class Address {
 	@NotNull
 	public static final String LINE = "__LINE__";
 
+	/**
+	 * An address used to store the output directory.
+	 *
+	 * @since 0.2.0 ~2021.06.03
+	 */
+	@NotNull
+	public static final String OUTPUT = "__OUTPUT__";
+
 	/**
 	 * An address used to allocate the current path.
 	 *

src/main/java/org/jamplate/impl/Jamplate.java

@@ -37,6 +37,7 @@
 import java.io.IOException;
 import java.text.SimpleDateFormat;
 import java.util.Date;
+import java.util.Map;
 import java.util.Objects;
 
 /**
@@ -446,10 +447,23 @@ public static boolean execute(@NotNull Environment environment, @Nullable Compil
 			if (instruction != null) {
 				Memory memory = new Memory();
 
+				Object memoryDefaults = environment.getMeta().get(Meta.MEMORY);
+
+				if (memoryDefaults instanceof Map)
+					((Map<?, ?>) memoryDefaults).forEach((key, value) -> {
+						String address = String.valueOf(key);
+						String text = String.valueOf(value);
+						memory.set(address, v -> text);
+					});
+
 				//set project dir
 				memory.set(
 						Address.PROJECT,
-						m -> String.valueOf(environment.getMeta().getOrDefault(Address.PROJECT, ""))
+						m -> String.valueOf(environment.getMeta().getOrDefault(Meta.PROJECT, ""))
+				);
+				memory.set(
+						Address.OUTPUT,
+						m -> String.valueOf(environment.getMeta().getOrDefault(Meta.OUTPUT, ""))
 				);
 				memory.set(
 						Address.JAMPLATE,

src/main/java/org/jamplate/impl/Meta.java

@@ -0,0 +1,62 @@
+/*
+ *	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.impl;
+
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * A class containing common meta keys.
+ *
+ * @author LSafer
+ * @version 0.2.0
+ * @since 0.2.0 ~2021.06.03
+ */
+public final class Meta {
+	/**
+	 * The key for the memory default allocations. The stored value must be of type {@link
+	 * java.util.Map}.
+	 *
+	 * @since 0.2.0 ~2021.06.03
+	 */
+	@NotNull
+	public static final String MEMORY = "memory";
+
+	/**
+	 * The key for the output directory.
+	 *
+	 * @since 0.2.0 ~2021.06.03
+	 */
+	@NotNull
+	public static final String OUTPUT = "output";
+
+	/**
+	 * The key for the project directory.
+	 *
+	 * @since 0.2.0 ~2021.06.03
+	 */
+	@NotNull
+	public static final String PROJECT = "project";
+
+	/**
+	 * Utility classes must not be initialized.
+	 *
+	 * @throws AssertionError when called.
+	 * @since 0.2.0 ~2021.06.03
+	 */
+	private Meta() {
+		throw new AssertionError("No instance for you");
+	}
+}

src/test/java/org/jamplate/FileTest.java

@@ -1,8 +1,8 @@
 //Use this class to manually test the directory test_input
 package org.jamplate;
 
-import org.jamplate.impl.Address;
 import org.jamplate.impl.Jamplate;
+import org.jamplate.impl.Meta;
 import org.jamplate.impl.model.EnvironmentImpl;
 import org.jamplate.impl.model.FileDocument;
 import org.jamplate.impl.model.PseudoDocument;
@@ -26,7 +26,7 @@ public void pseudo() {
 
 		Environment environment = new EnvironmentImpl();
 
-		environment.getMeta().put(Address.PROJECT, new File("test_input"));
+		environment.getMeta().put(Meta.PROJECT, new File("test_input"));
 
 		boolean compiled = Jamplate.compile(environment, documents);
 
@@ -68,7 +68,7 @@ public void run() {
 
 		Environment environment = new EnvironmentImpl();
 
-		environment.getMeta().put(Address.PROJECT, new File("test_input"));
+		environment.getMeta().put(Meta.PROJECT, new File("test_input"));
 
 		boolean compiled = Jamplate.compile(environment, documents);