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Just formatting App classes to be like the other class files on the project

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Matthew
2014-10-07 16:23:37 +01:00
parent 52f0923df9
commit bde5b343d0
24 changed files with 466 additions and 508 deletions
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111
interpreter/src/main/java/com/iluwatar/App.java
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@ -3,65 +3,64 @@ package com.iluwatar;
import java.util.Stack;
/**
*
* Interpreter pattern breaks sentences into expressions (Expression)
* that can be evaluated and as a whole form the result.
*
* Interpreter pattern breaks sentences into expressions (Expression) that can
* be evaluated and as a whole form the result.
*
*/
public class App
{
/**
*
* Expressions can be evaluated using prefix, infix or postfix notations
* This sample uses postfix, where operator comes after the operands
*
*/
public static void main( String[] args )
{
String tokenString = "4 3 2 - 1 + *";
Stack<Expression> stack = new Stack<>();
public class App {
String[] tokenList = tokenString.split(" ");
for (String s : tokenList) {
if (isOperator(s)) {
Expression rightExpression = stack.pop();
Expression leftExpression = stack.pop();
System.out.println(String.format("popped from stack left: %d right: %d",
leftExpression.interpret(), rightExpression.interpret()));
Expression operator = getOperatorInstance(s, leftExpression,
rightExpression);
System.out.println(String.format("operator: %s", operator));
int result = operator.interpret();
NumberExpression resultExpression = new NumberExpression(result);
stack.push(resultExpression);
System.out.println(String.format("push result to stack: %d", resultExpression.interpret()));
} else {
Expression i = new NumberExpression(s);
stack.push(i);
System.out.println(String.format("push to stack: %d", i.interpret()));
}
}
System.out.println(String.format("result: %d", stack.pop().interpret()));
/**
*
* Expressions can be evaluated using prefix, infix or postfix notations
* This sample uses postfix, where operator comes after the operands
*
*/
public static void main(String[] args) {
String tokenString = "4 3 2 - 1 + *";
Stack<Expression> stack = new Stack<>();
String[] tokenList = tokenString.split(" ");
for (String s : tokenList) {
if (isOperator(s)) {
Expression rightExpression = stack.pop();
Expression leftExpression = stack.pop();
System.out.println(String.format("popped from stack left: %d right: %d",
leftExpression.interpret(), rightExpression.interpret()));
Expression operator = getOperatorInstance(s, leftExpression,
rightExpression);
System.out.println(String.format("operator: %s", operator));
int result = operator.interpret();
NumberExpression resultExpression = new NumberExpression(result);
stack.push(resultExpression);
System.out.println(String.format("push result to stack: %d", resultExpression.interpret()));
} else {
Expression i = new NumberExpression(s);
stack.push(i);
System.out.println(String.format("push to stack: %d", i.interpret()));
}
}
System.out.println(String.format("result: %d", stack.pop().interpret()));
}
public static boolean isOperator(String s) {
if (s.equals("+") || s.equals("-") || s.equals("*"))
return true;
else
return false;
}
public static Expression getOperatorInstance(String s, Expression left,
Expression right) {
switch (s) {
case "+":
return new PlusExpression(left, right);
case "-":
return new MinusExpression(left, right);
case "*":
return new MultiplyExpression(left, right);
}
return null;
}
public static boolean isOperator(String s) {
if (s.equals("+") || s.equals("-") || s.equals("*")) {
return true;
} else {
return false;
}
}
public static Expression getOperatorInstance(String s, Expression left,
Expression right) {
switch (s) {
case "+":
return new PlusExpression(left, right);
case "-":
return new MinusExpression(left, right);
case "*":
return new MultiplyExpression(left, right);
}
return null;
}
}