From ed51d561ea8f4cd4c9187205d639cd891e893f25 Mon Sep 17 00:00:00 2001
From: Maël Gassmann <mael.gassmann@students.bfh.ch>
Date: Sat, 12 Jun 2021 18:40:00 +0200
Subject: [~] Added empty expression erroe messages

---
 calculator-javacc/Calculator.jj | 53 +++++++++++++++++++++++------------------
 1 file changed, 30 insertions(+), 23 deletions(-)

(limited to 'calculator-javacc')

diff --git a/calculator-javacc/Calculator.jj b/calculator-javacc/Calculator.jj
index 89a5802..b88937d 100644
--- a/calculator-javacc/Calculator.jj
+++ b/calculator-javacc/Calculator.jj
@@ -14,29 +14,33 @@ public class Calculator {
         while (true){
             System.out.print("Type your expression: ");
             try{
-                double value = parser.evaluateNextLine();
+
+                Double value = parser.evaluateNextLine();
                 System.out.println("Returned: " + value);
+
             }catch (ParseException e){  // Now we will parse the exception message to render it in our format.
-                int index = "Encountered: \"".length();
-                String em = e.getMessage().substring(index);
-                String token = em.substring(1,4);
-
-                if (token.equals("ILL")){ // Illegal token
-                    em = em.substring(7);
-                    index = em.indexOf("\"")-1;
-                    if (index == 0){ // Special case in which the illegal token would be '"'
-                        index = 2;
-                    }
-                    System.out.println("Illegal token: '"+ em.substring(0 , index) +"'.");
-                }else if(em.split("\n").length > 1){ //Other generated error messages
-                    index = em.indexOf("\"");
-                    if (index == 0){ // Meaning the last token is not <TOK> but "char"
-                        em = em.substring(1);
+                if(e.getMessage().split("\n").length > 1){ // The error message is on multiple line -> it had been generated
+                    int index = "Encountered: \"".length();
+                    String em = e.getMessage().substring(index);
+                    String token = em.substring(1,4);
+
+                    if (token.equals("ILL")){ // Illegal token
+                        em = em.substring(7);
+                        index = em.indexOf("\"")-1;
+                        if (index == 0){ // Special case in which the illegal token would be '"'
+                            index = 2;
+                        }
+                        System.out.println("Illegal token: '"+ em.substring(0 , index) +"'.");
+                    }else{ //Other generated error messages
                         index = em.indexOf("\"");
-                    }else{
-                        index--;
+                        if (index == 0){ // Meaning the last token is not <TOK> but "char"
+                            em = em.substring(1);
+                            index = em.indexOf("\"");
+                        }else{
+                            index--;
+                        }
+                        System.out.println("Last read token: '"+ em.substring(0 , index)+"', w"+em.substring(em.indexOf("\nW")+2));
                     }
-                    System.out.println("Last read token: '"+ em.substring(0 , index)+"', w"+em.substring(em.indexOf("\nW")+2));
                 }else{ //Those were error messages created by ourselves, they are one line messages that we can directly print
                     System.out.println(e.getMessage());
                 }
@@ -140,7 +144,7 @@ double factor() :
     double i = 0.0;
 }
 {
-    (t=<NUM> | id=<ID> | <PAL> (i=expression())? <PAR>)
+    (t=<NUM> | id=<ID> | <PAL> (i=expression()) <PAR>)
         {
             if(id != null){
                 Object var = variables.get(id.image);
@@ -152,7 +156,7 @@ double factor() :
                 i = Double.parseDouble(t.image);
             return i;
         }|
-    <SUB> (t=<NUM> | id=<ID> | <PAL> (i=expression())? <PAR>)
+    <SUB> (t=<NUM> | id=<ID> | <PAL> (i=expression()) <PAR>)
     {
             if(id != null){
                 i = (double)variables.get(id.image);
@@ -167,7 +171,9 @@ double evaluateNextLine() :
     double result = 0.0;
 }
 {
-	(result=statement())? <EOL> {return result;}|
+	(result=statement()) <EOL> {
+            return result;
+        }|
 	<EOF>{System.out.println("\nBuffer was closed. Exiting."); System.exit(0);}
 }
 
@@ -177,5 +183,6 @@ void passStatement() :
  }
 {
     (<ILL>|<PAL>|<PAR>|<ADD>|<SUB>|<MUL>|<DIV>|<EQU>|<LET>|<END>|<NUM>|<ID>)* <EOL>| //Skip any token until the next EOL
-	<EOF>{System.out.println("\nBuffer was closed. Exiting."); System.exit(0);}
+	<EOF>{System.out.println("\nBuffer was closed. Exiting."); System.exit(0);}|
+	{}
 }
\ No newline at end of file
-- 
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