First PoC version of the REPL has been done

src/main/java/serene/simple/DefSpecialForm.java

@@ -1,7 +1,7 @@
 package serene.simple;
 
 public class DefSpecialForm extends SpecialForm {
-    public DefSpecialForm(ListNode listNode) {
+    public DefSpecialForm(ListNode<Node> listNode) {
         super(listNode);
     }
 

src/main/java/serene/simple/Main.java

@@ -25,24 +25,29 @@ public class Main {
 
         System.out.println("Serene 'simple' v0.1.0");
         while(true) {
-            //String inputData = console.readLine("serene-> ");
-            String inputData = "(def a 4)";
+            String inputData = console.readLine("serene-> ");
 
             if (inputData == null) break;
 
             ByteArrayInputStream inputStream = new ByteArrayInputStream(inputData.getBytes());
             ListNode<Node> nodes = Reader.read(inputStream);
 
-            Object result = ListNode.EMPTY;
+            try {
+                Object result = ListNode.EMPTY;
+                for (Node n : nodes) {
+                    result = n.eval(rootScope);
+                }
 
-            for (Node n : nodes) {
-                result = n.eval(rootScope);
+                if (result != ListNode.EMPTY) {
+                    System.out.print(";; ");
+                    System.out.println(result);
+                }
+            }
+            catch(Exception e) {
+                System.out.println("Error: ");
+                e.printStackTrace(System.out);
             }
 
-            System.out.print(";; ");
-            if (result != ListNode.EMPTY) {
-                System.out.println(result);
-            }
         }
     }
 

src/main/java/serene/simple/Node.java

@@ -9,4 +9,8 @@ public abstract class Node {
         return this == n;
     }
 
+    public String toString() {
+        String className = this.getClass().getName();
+        return String.format("%s<%s>", className, System.identityHashCode(this));
+    }
 }

src/main/java/serene/simple/Reader.java

@@ -34,7 +34,6 @@ public class Reader {
 
     public static ListNode<Node> read(PushbackReader inputStream) throws IOException {
         List<Node> nodes = new ArrayList<Node>();
-
         skipWhiteSpaces(inputStream);
 
         char c = (char) inputStream.read();
@@ -72,19 +71,19 @@ public class Reader {
     }
 
     private static Node readSymbol(PushbackReader inputStream) throws IOException {
+        String str = "";
 
-      String str = "";
+        while (true) {
+            int ch = inputStream.read();
 
-      while (true) {
-          int ch = inputStream.read();
-          if(isWhiteSpace(ch)) {
-              inputStream.unread(ch);
-              break;
-          };
-          str = str + (char) ch;
-      }
+            if(isWhiteSpace(ch) || ch == -1) {
+                inputStream.unread(ch);
+                break;
+            };
+            str = str + (char) ch;
+        }
 
-      return new SymbolNode(str);
+        return new SymbolNode(str);
     }
 
     private static Node readNumber(PushbackReader inputStream) throws IOException {
@@ -109,6 +108,8 @@ public class Reader {
     }
 
     private static boolean isWhiteSpace(int ch) {
-        return (ch == ' ' || ch == '\t' || ch == '\f' || ch == '\r' || ch == '\n');
+        return (ch == ' ' || ch == '\t' ||
+                ch == '\f' || ch == '\r' ||
+                ch == '\n');
     }
 }

src/main/java/serene/simple/SpecialForm.java

@@ -14,12 +14,6 @@ public class SpecialForm extends Node {
     }
 
     public static Node check(ListNode<Node> l) {
-        if (l != ListNode.EMPTY && l.first() instanceof SymbolNode) {
-            System.out.println(">>>>");
-            //SymbolNode g = l.first();
-            //System.out.println(g.);
-        }
-
         if (l == ListNode.EMPTY) {
             return l;
         } else if (l.first().equals(DEF)) {

src/main/java/serene/simple/SymbolNode.java

@@ -1,25 +1,32 @@
 package serene.simple;
 
 public class SymbolNode extends Node {
-    public final String name;
+    public String name;
 
     public SymbolNode(String name) {
         this.name = name;
     }
 
+    @Override
+    public boolean equals(Node other) {
+        if (other instanceof SymbolNode) {
+            SymbolNode n = (SymbolNode) other;
 
-    public boolean equals(SymbolNode n) {
-        System.out.println("><<><>");
-        System.out.println(n.name);
-        if (this.name == n.name) {
-            return true;
+            if (this.name.equals(n.name)) {
+                return true;
+            }
+
+            return false;
         }
-
-        return false;
+        return super.equals(other);
     }
 
     @Override
     public Object eval(Scope scope) {
         return scope.lookupSymbol(this.name);
     }
+
+    public String toString() {
+        return String.format("Symbol<%s>", this.name);
+    }
 }