Interpreter Design Pattern - Artificial Intelligence Chat Bot

premaseem · premaseem · commit 681414aab92b · 2018-03-07T13:57:32.000-06:00
added Expression and Context with rules
diff --git a/pattern/src/com/premaseem/Client.java b/pattern/src/com/premaseem/Client.java
@@ -10,19 +10,33 @@
 public class Client {
     public static void main (String[] args) {
         System.out.println("Alexa welcomes you to Artificial intelligence app designed using Interpreter Design pattern :-) ");
-        Scanner scanner = new Scanner(System.in);
+        Scanner scanner1 = new Scanner(System.in);
+        Scanner scanner2 = new Scanner(System.in);
 
         // User input block
         String repeatRunFlag = "yes";
         while (!repeatRunFlag.equalsIgnoreCase("no")) {
             System.out.println("\n Please ask your question related to voting ...");
-            String question = scanner.nextLine();
-            Boolean result =true;
-            String voteEligible = result ? "Yes ! can vote :-) ":"No ! cannot vote :-)";
+            String question = scanner1.nextLine();
+
+            // get Voting context
+            Context votingContext = new VotingContext();
+
+            // get Rules or grammar around context
+            Expression ruleExpression = votingContext.getRuleExpression();
+
+            // question is interpreted based on context and rules
+            Boolean result = ruleExpression.interpret(question);
 
+            // print Results
+            String voteEligible = result ? "Yes ! can vote :-) ":"No ! cannot vote :-)";
             System.out.println("Alexa answered: " + voteEligible);
+
+            // Ask from another questions
             System.out.println("Do you have another questions ? yes / no ");
-            repeatRunFlag = scanner.next();
+            repeatRunFlag = scanner2.next();
         }
     }
 }
+
+
diff --git a/pattern/src/com/premaseem/Context.java b/pattern/src/com/premaseem/Context.java
@@ -0,0 +1,20 @@
+package com.premaseem;
+
+/*
+@author: Aseem Jain
+@title: Design Patterns with Java 9
+@link: https://premaseem.wordpress.com/category/computers/design-patterns/
+*/
+interface Context {
+    Expression getRuleExpression ();
+}
+
+class VotingContext implements Context {
+
+    @Override
+    public Expression getRuleExpression () {
+        Expression condition_1 = new TerminalExpression("citizen");
+        Expression condition_2 = new TerminalExpression("18");
+        return new AndExpression(condition_1, condition_2);
+    }
+}
diff --git a/pattern/src/com/premaseem/Expression.java b/pattern/src/com/premaseem/Expression.java
@@ -0,0 +1,63 @@
+package com.premaseem;
+
+/*
+@author: Aseem Jain
+@title: Design Patterns with Java 9
+@link: https://premaseem.wordpress.com/category/computers/design-patterns/
+*/
+interface Expression {
+    public boolean interpret (String context);
+}
+
+/**
+ * Terminal Expression is used in other expressions for interpretation
+ */
+class TerminalExpression implements Expression {
+
+    private String data;
+
+    public TerminalExpression(String data){
+        this.data = data;
+    }
+
+    @Override
+    public boolean interpret(String context) {
+        if(context.contains(data)){
+            return true;
+        }
+        return false;
+    }
+}
+
+class AndExpression implements Expression {
+
+    private Expression expr1 = null;
+    private Expression expr2 = null;
+
+    public AndExpression(Expression expr1, Expression expr2) {
+        this.expr1 = expr1;
+        this.expr2 = expr2;
+    }
+
+    @Override
+    public boolean interpret(String context) {
+        return expr1.interpret(context) && expr2.interpret(context);
+    }
+}
+
+class OrExpression implements Expression {
+
+    private Expression expr1 = null;
+    private Expression expr2 = null;
+
+    public OrExpression(Expression expr1, Expression expr2) {
+        this.expr1 = expr1;
+        this.expr2 = expr2;
+    }
+
+    @Override
+    public boolean interpret(String context) {
+        return expr1.interpret(context) || expr2.interpret(context);
+    }
+}
+
diff --git a/patternBonus/src/com/premaseem/Client.java b/patternBonus/src/com/premaseem/Client.java
