From bae1617237f4636a5066d00b761290afbe14539a Mon Sep 17 00:00:00 2001
From: Kraemerd <Dominic_Daniel.Kraemer@Student.Reutlingen-University.de>
Date: Mon, 9 Jan 2023 23:20:09 +0100
Subject: [PATCH] implemented that * and / get calculated before + and - (if
the next expression is not capsuled)
---
expressions.txt | 13 ++++----
src/main/ASTPrinter.java | 3 ++
src/main/Application.java | 6 +++-
src/main/Evaluator.java | 64 +++++++++++++++++++++++++++++----------
src/main/Parser.java | 36 +++++++++++++++++++---
src/main/Visitor.java | 2 ++
src/test/LexerTest.java | 8 ++---
src/test/ParserTest.java | 14 ++++-----
8 files changed, 108 insertions(+), 38 deletions(-)
diff --git a/expressions.txt b/expressions.txt
index bcba895..ba3d614 100644
--- a/expressions.txt
+++ b/expressions.txt
@@ -1,6 +1,7 @@
-2*(4^2)
-(4+2)*4
-(4+2*(4-2))
-((3+2)*(12+2))
-1+(x^2.22)-(3*x)
-2*x+0.5*(x^2+4)-1
\ No newline at end of file
+1+1
+2*4+x
+2*5+2
+2+5*2
+2*(5+2)
+20*(5^2)
+(x^2)+50*x+2
\ No newline at end of file
diff --git a/src/main/ASTPrinter.java b/src/main/ASTPrinter.java
index 118fb24..2b7c72b 100644
--- a/src/main/ASTPrinter.java
+++ b/src/main/ASTPrinter.java
@@ -1,5 +1,7 @@
package main;
+import java.util.List;
+
/**
* <h1>The ASTPrinter</h1>
* The ASTPrinter class creates a String out of an AST(represented through an Expression object)
@@ -15,6 +17,7 @@ public class ASTPrinter implements Visitor<String>{
* Builds a String representation of a given BinaryOperation
* It gets a String representation of its left and right Expressions (which may result in a
* recursive call) and combines them into one String together with the operator
+ *
* @param binaryOP The BinaryOperation that should be printed into a String
* @return String Returns the String that was build
*/
diff --git a/src/main/Application.java b/src/main/Application.java
index 3c5b0cf..dd30e02 100644
--- a/src/main/Application.java
+++ b/src/main/Application.java
@@ -36,8 +36,10 @@ public class Application {
List<Lexer.Token> tokens = Lexer.lex(expressionString);
System.out.println("Lexer created tokens:");
//prints out each token to the console
+ int i = 0;
for(Lexer.Token token: tokens) {
- System.out.println(token.toString());
+ System.out.println("[" + i + "]" + token.toString());
+ i++;
}
//Parse all tokens with the parser and saves the result into the variable 'ast'
Parser parser = new Parser();
@@ -46,6 +48,8 @@ public class Application {
//the result can later be used to show the ast in a function plotter
ASTPrinter printer = new ASTPrinter();
System.out.println("Printing: '" + printer.visit(ast) + "'");
+ Evaluator evaluator = new Evaluator();
+ System.out.println(evaluator.visit(ast, 20));
System.out.println();
}
catch (Exception e) {
diff --git a/src/main/Evaluator.java b/src/main/Evaluator.java
index 7f51f3c..62a37d8 100644
--- a/src/main/Evaluator.java
+++ b/src/main/Evaluator.java
@@ -1,50 +1,84 @@
package main;
+import java.util.LinkedList;
+import java.util.List;
+
public class Evaluator implements Visitor<Double>{
+ private int x;
+
@Override
public Double visit(final Parser.BinaryOperation binaryOP) {
- double result = binaryOP.leftExpression.accept(this);
- Double rOperand = binaryOP.rightExpression.accept(this);
- if(rOperand==null) {
+ int range = 20;
+ List<Double> results = new LinkedList<>();
+ for(int index=-20; index<=range; index++) {
}
+ double result = binaryOP.leftExpression.accept(this);
+ double rOperand;
+
switch (binaryOP.operator.charAt(0)) {
case '+':
+ rOperand = binaryOP.rightExpression.accept(this);
result += rOperand;
break;
case '-':
+ rOperand = binaryOP.rightExpression.accept(this);
result -= rOperand;
break;
case '*':
- rOperand *= rOperand;
- result *= rOperand;
+ if(binaryOP.rightExpression instanceof Parser.BinaryOperation) {;
+ if(((Parser.BinaryOperation) binaryOP.rightExpression).capsuled) {
+ rOperand = binaryOP.rightExpression.accept(this);
+ result *= rOperand;
+ }
+ else {
+ //***************************************************************************************
+ result = ((Parser.BinaryOperation) binaryOP.rightExpression).accept(this, result, "*");
+ }
+ }
+ else {
+ rOperand = binaryOP.rightExpression.accept(this);
+ result *= rOperand;
+ }
break;
case '/':
- if (rOperand != 0) {
- result /= rOperand;
+ if (binaryOP.rightExpression instanceof Parser.BinaryOperation) {
+ if(binaryOP.capsuled) {
+ rOperand = binaryOP.rightExpression.accept(this);
+ result /= rOperand;
+ }
+ else {
+ //***************************************************************************************
+ result = ((Parser.BinaryOperation) binaryOP.rightExpression).accept(this, result, "/");
+ }
}
else {
- result = result;
- //throw new ArithmeticException("Arithmetic Error: division by zero detected");
+ rOperand = binaryOP.rightExpression.accept(this);
+ if(rOperand!=0) {
+ result /= rOperand;
+ }
+ else {
+ throw new ArithmeticException("Arithmetic Error: division by zero detected");
+ }
}
break;
case '^':
+ rOperand = binaryOP.rightExpression.accept(this);
for(int i=1; i<rOperand; i++) {
result = result*result;
}
break;
default:
- throw new RuntimeException("SematicError: unknown operand found in AST: "
- + binaryOP.operator);
+ throw new RuntimeException("SemanticError: unknown operand found in AST: " + binaryOP.operator);
}
return result;
}
@Override
public Double visit(final Parser.Variable variable) {
- return 0.0;
+ return variable.value * x;
}
@Override
@@ -57,10 +91,8 @@ public class Evaluator implements Visitor<Double>{
return Double.valueOf(decimal.afterDot.digits + "." + decimal.beforeDot.digits);
}
- public double visit(final Parser.Expression ast) {
- if(ast==null) {
- return 0.0;
- }
+ public Double visit(final Parser.Expression ast, int x) {
+ this.x = x;
return ast.accept(this);
}
}
diff --git a/src/main/Parser.java b/src/main/Parser.java
index 8b7cb02..73327dd 100644
--- a/src/main/Parser.java
+++ b/src/main/Parser.java
@@ -22,6 +22,7 @@ public class Parser {
*/
public abstract class Expression {
public abstract <T> T accept(Visitor<T> visitor);
+ public abstract <T> T accept(Visitor<T> visitor, double leftValue, String operator);
}
/**
@@ -40,11 +41,13 @@ public class Parser {
this.rightExpression = rightExpression;
this.capsuled = capsuled;
}
+ @Override
public <T> T accept(Visitor<T> visitor) {
return visitor.visit(this);
}
- public <T> T accept(Visitor<T> visitor, String operator) {
+ public <T> T accept(Visitor<T> visitor, double leftValue, String operator) {
+ leftExpression.accept(visitor, leftValue, operator);
return visitor.visit(this);
}
}
@@ -54,13 +57,24 @@ public class Parser {
* of the alphabet
*/
public class Variable extends Expression {
+ double value;
String variableName;
- public Variable(String i, Boolean capsuled) {
- this.variableName = i;
+ public Variable(String i) {
+ this.value = 1.0;
+ variableName = i;
}
public <T> T accept(Visitor<T> visitor) {
return visitor.visit(this);
}
+ public <T> T accept(Visitor<T> visitor, double leftValue, String operator) {
+ if(operator.equals("*")) {
+ this.value = leftValue;
+ }
+ else {
+ this.value = 1/leftValue;
+ }
+ return visitor.visit(this);
+ }
}
/**
@@ -82,6 +96,15 @@ public class Parser {
public <T> T accept(Visitor<T> visitor) {
return visitor.visit(this);
}
+ public <T> T accept(Visitor<T> visitor, double leftValue, String operator) {
+ if(operator.equals("*")) {
+ this.digits = String.valueOf((leftValue * Double.parseDouble(this.digits)));
+ }
+ else {
+ this.digits = String.valueOf((leftValue / Integer.parseInt(this.digits)));
+ }
+ return visitor.visit(this);
+ }
}
/**
@@ -98,6 +121,11 @@ public class Parser {
public <T> T accept(Visitor<T> visitor) {
return visitor.visit(this);
}
+ public <T> T accept(Visitor<T> visitor, double leftValue, String operator) {
+ beforeDot.accept(visitor, leftValue, operator);
+ afterDot.accept(visitor, leftValue, operator);
+ return visitor.visit(this);
+ }
}
/**
@@ -298,7 +326,7 @@ public class Parser {
if(!parseCharacter(data,"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz")) {
throw new ParserException("Invalid variable character: " + data);
}
- return new Variable(data, false);
+ return new Variable(data);
}
diff --git a/src/main/Visitor.java b/src/main/Visitor.java
index 88d87ae..246556f 100644
--- a/src/main/Visitor.java
+++ b/src/main/Visitor.java
@@ -1,5 +1,7 @@
package main;
+import java.util.List;
+
public interface Visitor<T>{
public T visit(final Parser.BinaryOperation binOp);
public T visit(final Parser.Variable variable);
diff --git a/src/test/LexerTest.java b/src/test/LexerTest.java
index 54356a6..aaceea7 100644
--- a/src/test/LexerTest.java
+++ b/src/test/LexerTest.java
@@ -3,16 +3,16 @@ package test;
import org.junit.Test;
import main.*;
-import java.io.IOException;
import java.util.LinkedList;
import java.util.List;
+import static org.junit.Assert.assertThat;
import static org.junit.jupiter.api.Assertions.*;
-class LexerTest {
+ class LexerTest {
@Test
- void disassembleFirstStringWithLexer() {
+ public void disassembleFirstStringWithLexer() {
String s = "3+x*(2^4)";
List<Lexer.Token> tokens = new LinkedList<>();
tokens.add(new Lexer.Token(Lexer.TokenType.NUMBER,"3"));
@@ -33,7 +33,7 @@ class LexerTest {
}
@Test
- void disassembleSecondStringWithLexer() {
+ public void disassembleSecondStringWithLexer() {
String s = "1 + (x^2 )- (3*x)";
List<Lexer.Token> tokens = new LinkedList<>();
tokens.add(new Lexer.Token(Lexer.TokenType.NUMBER,"1"));
diff --git a/src/test/ParserTest.java b/src/test/ParserTest.java
index 2d70d2e..e58b077 100644
--- a/src/test/ParserTest.java
+++ b/src/test/ParserTest.java
@@ -7,10 +7,10 @@ import org.junit.Test;
import java.util.LinkedList;
import java.util.List;
-public class ParserTest {
+class ParserTest {
@Test
- void testParseVariable() {
+ public void testParseVariable() {
List<Lexer.Token> tokens = new LinkedList<>();
tokens.add(new Lexer.Token(Lexer.TokenType.VARIABLE,"x"));
var parser = new Parser();
@@ -23,7 +23,7 @@ public class ParserTest {
}
@Test
- void testWrongVariableInput() {
+ public void testWrongVariableInput() {
List<Lexer.Token> tokens = new LinkedList<>();
tokens.add(new Lexer.Token(Lexer.TokenType.VARIABLE,"xy"));
var parser = new Parser();
@@ -36,7 +36,7 @@ public class ParserTest {
}
@Test
- void testParseNumber() {
+ public void testParseNumber() {
List<Lexer.Token> tokens = new LinkedList<>();
tokens.add(new Lexer.Token(Lexer.TokenType.NUMBER,"23"));
var parser = new Parser();
@@ -49,7 +49,7 @@ public class ParserTest {
}
@Test
- void testWrongNumberInput() {
+ public void testWrongNumberInput() {
List<Lexer.Token> tokens = new LinkedList<>();
tokens.add(new Lexer.Token(Lexer.TokenType.NUMBER,"02.4"));
var parser = new Parser();
@@ -62,7 +62,7 @@ public class ParserTest {
}
@Test
- void testParseBinaryOperation() {
+ public void testParseBinaryOperation() {
List<Lexer.Token> tokens = new LinkedList<>();
tokens.add(new Lexer.Token(Lexer.TokenType.SPECIAL,"("));
tokens.add(new Lexer.Token(Lexer.TokenType.NUMBER,"5"));
@@ -81,7 +81,7 @@ public class ParserTest {
}
@Test
- void testParseWrongBinaryOperation() {
+ public void testParseWrongBinaryOperation() {
List<Lexer.Token> tokens = new LinkedList<>();
tokens.add(new Lexer.Token(Lexer.TokenType.SPECIAL,"("));
tokens.add(new Lexer.Token(Lexer.TokenType.NUMBER,"5"));
--
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