From 1cc74ba62ff35009bdf177a570e95b5c27d9ee08 Mon Sep 17 00:00:00 2001
From: rylon <rylon@web.de>
Date: Thu, 22 Dec 2011 04:45:57 +0100
Subject: [PATCH] =?UTF-8?q?vorl=C3=A4ufige=20solution=20f=C3=BCr=20aufgabe?=
 =?UTF-8?q?=202.1?=
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---
 .../Uebungen/2. Uebung/c1-ex02/SymbolTable.java    | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/ws2011/Compiler I/Uebungen/2. Uebung/c1-ex02/SymbolTable.java b/ws2011/Compiler I/Uebungen/2. Uebung/c1-ex02/SymbolTable.java
index daeeeb51..306c059d 100644
--- a/ws2011/Compiler I/Uebungen/2. Uebung/c1-ex02/SymbolTable.java	
+++ b/ws2011/Compiler I/Uebungen/2. Uebung/c1-ex02/SymbolTable.java	
@@ -12,16 +12,26 @@ public final class SymbolTable {
   private List<List<String>> scopeStack;
 
   public SymbolTable () {
+      symtab = new Map<String, Stack<Declaration>>();
+      scopeStack = new List<List<String>>();
   }
 
   // Opens a new level in the identification table, 1 higher than the
   // current topmost level.
   public void openScope () {
+        // new empty list
+	scopeStack.add(new List<String>());
   }
 
   // Closes the topmost level in the identification table, discarding
   // all entries belonging to that level.
   public void closeScope () {
+      //delete from symtab
+      for(int i = 0; i < scopeStack.get(scopeStack.size() -1).size(); i++){
+         symtab.remove(scopeStack.get(scopeStack.size() -1).get(i));
+      }
+      // delete top list
+      scopeStack.remove(scopeStack.size()-1);
   }
 
   // Makes a new entry in the identification table for the given identifier
@@ -29,6 +39,8 @@ public final class SymbolTable {
   // duplicated is set to to true if there is already an entry for the
   // same identifier at the current level.
   public void enter (String id, Declaration attr) {
+      scopeStack.get(scopeStack.size()-1).add(id);
+      symtab.put(id, attr);
   }
 
   // Finds an entry for the given identifier in the identification table,
@@ -37,7 +49,7 @@ public final class SymbolTable {
   // Returns null if no entry is found.
   // otherwise returns the attribute field of the entry found.
   public Declaration retrieve (String id) {
-	  return null;
+	  return symtab.containsKey(id);
   }
 
 }