From 403c6a951e890d3e1914779ee35576859a38d33e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ma=C3=ABl=20Gassmann?= <mael.gassmann@students.bfh.ch>
Date: Fri, 11 Jun 2021 11:17:45 +0200
Subject: [+] implemented the 'shell' UI, [~] Small corrections had to be made
 in the parser

---
 .../src/main/java/ch/bfh/CalculatorLexer.java      |  2 +-
 calculator-java/src/main/java/ch/bfh/Main.java     | 28 ++++++++++++----------
 .../main/java/ch/bfh/parser/ExpressionParser.java  |  8 +++++--
 .../src/main/java/ch/bfh/parser/Parser.java        |  4 +---
 4 files changed, 24 insertions(+), 18 deletions(-)

(limited to 'calculator-java/src')

diff --git a/calculator-java/src/main/java/ch/bfh/CalculatorLexer.java b/calculator-java/src/main/java/ch/bfh/CalculatorLexer.java
index ba10944..48d009e 100644
--- a/calculator-java/src/main/java/ch/bfh/CalculatorLexer.java
+++ b/calculator-java/src/main/java/ch/bfh/CalculatorLexer.java
@@ -82,7 +82,7 @@ public class CalculatorLexer {
       }
       else
         if (Character.isLetter(src.charAt(idx))) {
-          tok.value = 0;  
+          tok.value = 0;
           tok.type  = Token.ID;
           tok.str   = identifier();
           if (tok.str.compareTo("let")==0)  tok.type = Token.LET;
diff --git a/calculator-java/src/main/java/ch/bfh/Main.java b/calculator-java/src/main/java/ch/bfh/Main.java
index b0dedf3..302f5ed 100644
--- a/calculator-java/src/main/java/ch/bfh/Main.java
+++ b/calculator-java/src/main/java/ch/bfh/Main.java
@@ -3,21 +3,25 @@ package ch.bfh;
 import ch.bfh.parser.ExpressionParser;
 
 import java.util.Arrays;
+import java.util.Scanner;
 
 public class Main {
 
     public static void main(String[] args){
-        CalculatorLexer cl = new CalculatorLexer();
-
-        //TODO - command line reader instead of arg
-
-        // Combines the arguments & init the lexer
-        cl.initLexer(
-                Arrays.stream(args).reduce("", (expression, arg) -> expression + arg)
-        );
-
-        ExpressionParser ep = new ExpressionParser(cl);
-
-        System.out.println(ep.getValue());
+        Scanner scanner = new Scanner(System.in);
+
+        while (true) {
+            CalculatorLexer cl = new CalculatorLexer();
+            System.out.print("Type your expression: ");
+            String expression = scanner.nextLine();
+
+            try {
+                cl.initLexer(expression);
+                ExpressionParser ep = new ExpressionParser(cl);
+                System.out.println(ep.getValue());
+            } catch (Exception e) {
+                System.out.println(e.getMessage());
+            }
+        }
     }
 }
diff --git a/calculator-java/src/main/java/ch/bfh/parser/ExpressionParser.java b/calculator-java/src/main/java/ch/bfh/parser/ExpressionParser.java
index 229e700..f96353e 100644
--- a/calculator-java/src/main/java/ch/bfh/parser/ExpressionParser.java
+++ b/calculator-java/src/main/java/ch/bfh/parser/ExpressionParser.java
@@ -49,6 +49,7 @@ public class ExpressionParser extends Parser {
                 case Token.SUB:
                     if (l != null && op == null) { // if the '-' sign is between two term (op)
                         op = token;
+                        this.ops.add(op);
                         break;
                     } else if (l != null && r != null) { // if we already found a 'l op r' we roll
                         l = r;
@@ -69,7 +70,7 @@ public class ExpressionParser extends Parser {
                     }
                     continue loop;
                 case Token.PAR:
-                    if (lastToken.type == Token.PAL) { // if equal to '(' it means it was created by a Factor
+                    if (lastToken != null && lastToken.type == Token.PAL) { // if equal to '(' it means it was created by a Factor
                         lastToken = token;
                         break loop;
                     } else
@@ -260,7 +261,10 @@ public class ExpressionParser extends Parser {
             @Override
             public double getValue(){
                 if (expression != null)
-                    return expression.getValue();
+                    if (isNegative)
+                        return expression.getValue()*(-1);
+                    else
+                        return expression.getValue();
                 if (isNegative)
                     return value*(-1);
                 return value;
diff --git a/calculator-java/src/main/java/ch/bfh/parser/Parser.java b/calculator-java/src/main/java/ch/bfh/parser/Parser.java
index 755313a..9e048a6 100644
--- a/calculator-java/src/main/java/ch/bfh/parser/Parser.java
+++ b/calculator-java/src/main/java/ch/bfh/parser/Parser.java
@@ -9,8 +9,6 @@ abstract class Parser{
     protected double value;
 
     protected abstract void parse();
-    public double getValue(){
-        return value;
-    }
+    public abstract double getValue();
 }
 
-- 
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