tasks a-s

Task/S-Expressions/Java/s-expressions-5.java

@@ -0,0 +1,71 @@
+package jfkbits;
+
+import java.util.AbstractCollection;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.ArrayList;
+
+import jfkbits.LispParser.Expr;
+
+public class ExprList extends ArrayList<Expr> implements Expr
+{
+    ExprList parent = null;
+    int indent =1;
+
+    public int getIndent()
+    {
+        if (parent != null)
+        {
+            return parent.getIndent()+indent;
+        }
+        else return 0;
+    }
+
+    public void setIndent(int indent)
+    {
+        this.indent = indent;
+    }
+
+
+
+    public void setParent(ExprList parent)
+    {
+        this.parent = parent;
+    }
+
+    public String toString()
+    {
+        String indent = "";
+        if (parent != null && parent.get(0) != this)
+        {
+            indent = "\n";
+            char[] chars = new char[getIndent()];
+            Arrays.fill(chars, ' ');
+            indent += new String(chars);		
+        }
+
+        String output = indent+"(";
+        for(Iterator<Expr> it=this.iterator(); it.hasNext(); )
+        {
+            Expr expr = it.next();
+            output += expr.toString();
+            if (it.hasNext())
+                output += " ";
+        }
+        output += ")";
+        return output;
+    }
+
+    @Override
+    public synchronized boolean add(Expr e)
+    {
+        if (e instanceof ExprList)
+        {
+            ((ExprList) e).setParent(this);
+            if (size() != 0 && get(0) instanceof Atom)
+                ((ExprList) e).setIndent(2);
+        }
+        return super.add(e);
+    }
+
+}