Introducing Reader monad

README.md

@@ -48,7 +48,7 @@ Then, you can add the dependency to your project.
 <dependency>
   <groupId>com.github.VassilisSoum</groupId>
   <artifactId>FunctionalUtils</artifactId>
-  <version>2.0.0</version>
+  <version>2.1.0</version>
 </dependency>
 ```
 

pom.xml

@@ -6,7 +6,7 @@
 
   <groupId>com.soumakis</groupId>
   <artifactId>FunctionalUtils</artifactId>
-  <version>2.0.0</version>
+  <version>2.1.0</version>
   <packaging>jar</packaging>
 
   <properties>

src/main/java/com/soumakis/control/Reader.java

@@ -0,0 +1,36 @@
+package com.soumakis.control;
+
+import java.util.function.Function;
+
+/**
+ * Reader monad implementation. This is a simple implementation of the Reader monad. It is used to
+ * pass a context to a computation. The computation is a function that takes the context as an
+ * argument and returns a value. The Reader monad allows us to chain computations that depend on the
+ * context without passing the context explicitly.
+ *
+ * @param <C> the context type
+ * @param <T> the result type
+ */
+public class Reader<C, T> {
+
+  private final Function<C, T> computation;
+
+  private Reader(Function<C, T> computation) {
+    this.computation = computation;
+  }
+
+  /**
+   * Runs the computation with the given context.
+   *
+   * @param context the context
+   * @return the result of the computation
+   */
+  public T run(C context) {
+    return computation.apply(context);
+  }
+
+  public static <C, T> Reader<C, T> of(Function<C, T> computation) {
+    return new Reader<>(computation);
+  }
+
+}

src/test/java/com/soumakis/control/ReaderTest.java

@@ -0,0 +1,14 @@
+package com.soumakis.control;
+
+import org.junit.jupiter.api.Test;
+
+public class ReaderTest {
+
+  @Test
+  void testRun() {
+    Reader<Integer, Integer> reader = Reader.of((Integer context) -> context + 1);
+
+    assert (reader.run(1) == 2);
+  }
+
+}