add provisional characterchecker

src/main/java/io/zipcoder/ParenChecker.java

@@ -6,11 +6,13 @@ public class ParenChecker {
     public String string;
     public Stack<String> openParen;
     public Stack<String> closeParen;
+    public Stack<String> quotes;
 
     public ParenChecker(String entry){
         this.string = entry;
         this.openParen = new Stack<String>();
         this.closeParen = new Stack<String>();
+        this.quotes = new Stack<String>();
     }
 
     public boolean checkParen(){
@@ -27,4 +29,22 @@ public boolean checkParen(){
         return true;
     }
 
+    public boolean checkCharacters(){
+        for (String letter:string.split("")) {
+            if (letter.equals("(") || letter.equals("{") || letter.equals("[") || letter.equals("<")){
+                openParen.push(letter);
+            }
+            if (letter.equals(")") || letter.equals("}") || letter.equals("]") || letter.equals(">")){
+                closeParen.push(letter);
+                if (openParen.size()<closeParen.size()) return false;
+            }
+            if (letter.equals("\"") || letter.equals("'")){
+                quotes.push(letter);
+            }
+        }
+        if (openParen.size() != closeParen.size()) return false;
+        if (quotes.size() % 2 == 1) return false;
+        return true;
+    }
+
 }

src/test/java/io/zipcoder/ParenCheckerTest.java

@@ -35,4 +35,22 @@ public void checkParenTest4(){
         Assert.assertFalse(parenChecker.checkParen());
     }
 
+    @Test
+    public void checkCharacters(){
+        parenChecker = new ParenChecker("wef'wfe'wfe");
+        Assert.assertTrue(parenChecker.checkCharacters());
+    }
+
+    @Test
+    public void checkCharacters2(){
+        parenChecker = new ParenChecker("w\"ef\"wfe\"wfe");
+        Assert.assertFalse(parenChecker.checkCharacters());
+    }
+
+    @Test
+    public void checkCharacters3(){
+        parenChecker = new ParenChecker("w\"e'f\"wf'e\"wfe");
+        Assert.assertFalse(parenChecker.checkCharacters());
+    }
+
 }