Add InterpreterPattern.

chrish · chrish · commit e32c9b84051b · 2017-10-24T17:10:41.000+08:00
diff --git a/Behavioral/InterpreterPattern/src/io/csie/chris/Evaluator.java b/Behavioral/InterpreterPattern/src/io/csie/chris/Evaluator.java
@@ -1,6 +1,11 @@
 package io.csie.chris;
 
 import io.csie.chris.expression.*;
+import io.csie.chris.expression.common.Expression;
+import io.csie.chris.expression.operation.Divide;
+import io.csie.chris.expression.operation.Minus;
+import io.csie.chris.expression.operation.Multiplication;
+import io.csie.chris.expression.operation.Plus;
 
 import java.util.Map;
 import java.util.Stack;
@@ -31,6 +36,12 @@ public class Evaluator implements Expression {
                     final Expression multiExpression = new Multiplication(expressionStack.pop(), expressionStack.pop());
                     expressionStack.push(multiExpression);
                     break;
+                case  "/":
+                    final Expression rightOperand = expressionStack.pop();
+                    final Expression leftOperand = expressionStack.pop();
+                    final Expression divideExpression = new Divide(leftOperand, rightOperand);
+                    expressionStack.push(divideExpression);
+                    break;
                 default:
                     expressionStack.push(new Variable(token));
                     break;
diff --git a/Behavioral/InterpreterPattern/src/io/csie/chris/Main.java b/Behavioral/InterpreterPattern/src/io/csie/chris/Main.java
@@ -1,7 +1,7 @@
 package io.csie.chris;
 
-import io.csie.chris.expression.Expression;
-import io.csie.chris.expression.Number;
+import io.csie.chris.expression.common.Expression;
+import io.csie.chris.expression.operation.Number;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -10,12 +10,13 @@ public class Main {
 
     public static void main(final String[] args) {
 
-        final String expression = "v w x z - + *";
+        final String expression = "u v w x z - + * /";
 
         final Evaluator sentence = new Evaluator(expression);
 
         final Map<String, Expression> variables = new HashMap<>();
 
+        variables.put("u", new Number(108));
         variables.put("v", new Number(2));
         variables.put("w", new Number(5));
         variables.put("x", new Number(10));
diff --git a/Behavioral/InterpreterPattern/src/io/csie/chris/expression/Variable.java b/Behavioral/InterpreterPattern/src/io/csie/chris/expression/Variable.java
@@ -1,5 +1,7 @@
 package io.csie.chris.expression;
 
+import io.csie.chris.expression.common.Expression;
+
 import java.util.Map;
 
 public class Variable implements Expression {
diff --git a/Behavioral/InterpreterPattern/src/io/csie/chris/expression/common/Expression.java b/Behavioral/InterpreterPattern/src/io/csie/chris/expression/common/Expression.java
@@ -1,4 +1,4 @@
-package io.csie.chris.expression;
+package io.csie.chris.expression.common;
 
 import java.util.Map;
 
diff --git a/Behavioral/InterpreterPattern/src/io/csie/chris/expression/operation/Divide.java b/Behavioral/InterpreterPattern/src/io/csie/chris/expression/operation/Divide.java
@@ -0,0 +1,22 @@
+package io.csie.chris.expression.operation;
+
+import io.csie.chris.expression.common.Expression;
+
+import java.util.Map;
+
+public class Divide implements Expression {
+
+    private Expression leftOperand;
+
+    private Expression rightOperand;
+
+    public Divide(Expression leftOperand, Expression rightOperand) {
+        this.leftOperand = leftOperand;
+        this.rightOperand = rightOperand;
+    }
+
+    @Override
+    public int interpret(Map<String, Expression> variables) {
+        return leftOperand.interpret(variables) / rightOperand.interpret(variables);
+    }
+}
diff --git a/Behavioral/InterpreterPattern/src/io/csie/chris/expression/operation/Minus.java b/Behavioral/InterpreterPattern/src/io/csie/chris/expression/operation/Minus.java
@@ -1,4 +1,6 @@
-package io.csie.chris.expression;
+package io.csie.chris.expression.operation;
+
+import io.csie.chris.expression.common.Expression;
 
 import java.util.Map;
 
diff --git a/Behavioral/InterpreterPattern/src/io/csie/chris/expression/operation/Multiplication.java b/Behavioral/InterpreterPattern/src/io/csie/chris/expression/operation/Multiplication.java
@@ -1,8 +1,10 @@
-package io.csie.chris.expression;
+package io.csie.chris.expression.operation;
+
+import io.csie.chris.expression.common.Expression;
 
 import java.util.Map;
 
-public class Multiplication implements Expression{
+public class Multiplication implements Expression {
 
     private Expression leftOperand;
 
diff --git a/Behavioral/InterpreterPattern/src/io/csie/chris/expression/operation/Number.java b/Behavioral/InterpreterPattern/src/io/csie/chris/expression/operation/Number.java
@@ -1,4 +1,6 @@
-package io.csie.chris.expression;
+package io.csie.chris.expression.operation;
+
+import io.csie.chris.expression.common.Expression;
 
 import java.util.Map;
 
diff --git a/Behavioral/InterpreterPattern/src/io/csie/chris/expression/operation/Plus.java b/Behavioral/InterpreterPattern/src/io/csie/chris/expression/operation/Plus.java
@@ -1,4 +1,6 @@
-package io.csie.chris.expression;
+package io.csie.chris.expression.operation;
+
+import io.csie.chris.expression.common.Expression;
 
 import java.util.Map;
 

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-package io.csie.chris.expression;`
	`1`	`+package io.csie.chris.expression.common;`
`2`	`2`
`3`	`3`	`import java.util.Map;`
`4`	`4`