Formatting, ready for part 2

p3/src/relop/FileScan.java

@@ -26,8 +26,8 @@ public class FileScan extends Iterator {
     }
 
     /**
-   * Gives a one-line explanation of the iterator, repeats the call on any
+     * Gives a one-line explanation of the iterator, repeats the call on any child
-   * child iterators, and increases the indent depth along the way.
+     * iterators, and increases the indent depth along the way.
      */
     public void explain(int depth) {
         for (int i = 0; i < depth; i++) {

p3/src/relop/HashJoin.java

@@ -8,14 +8,19 @@ import global.AttrOperator;
 import global.AttrType;
 
 public class HashJoin extends Iterator {
+    private Iterator outer;
+    private Iterator inner;
+    private Predicate[] preds;
 
     public HashJoin(Iterator aIter1, Iterator aIter2, int aJoinCol1, int aJoinCol2) {
-		throw new UnsupportedOperationException("Not implemented");
+        aIter1.getSchema().getLength();
+        this.outer = aIter1;
+        this.inner = aIter2;
     }
 
     /**
-	* Gives a one-line explanation of the iterator, repeats the call on any
+     * Gives a one-line explanation of the iterator, repeats the call on any child
-	* child iterators, and increases the indent depth along the way.
+     * iterators, and increases the indent depth along the way.
      */
     public void explain(int depth) {
         throw new UnsupportedOperationException("Not implemented");

p3/src/relop/IndexScan.java

@@ -15,7 +15,6 @@ public class IndexScan extends Iterator {
     private HashIndex index = null;
     private boolean isOpen = false;
 
-
     /**
      * Constructs an index scan, given the hash index and schema.
      */
@@ -28,8 +27,8 @@ public class IndexScan extends Iterator {
     }
 
     /**
-   * Gives a one-line explaination of the iterator, repeats the call on any
+     * Gives a one-line explaination of the iterator, repeats the call on any child
-   * child iterators, and increases the indent depth along the way.
+     * iterators, and increases the indent depth along the way.
      */
     public void explain(int depth) {
         throw new UnsupportedOperationException("Not implemented");

p3/src/relop/KeyScan.java

@@ -29,8 +29,8 @@ public class KeyScan extends Iterator {
     }
 
     /**
-   * Gives a one-line explanation of the iterator, repeats the call on any
+     * Gives a one-line explanation of the iterator, repeats the call on any child
-   * child iterators, and increases the indent depth along the way.
+     * iterators, and increases the indent depth along the way.
      */
     public void explain(int depth) {
         throw new UnsupportedOperationException("Not implemented");

p3/src/relop/Projection.java

@@ -1,22 +1,39 @@
 package relop;
 
-
 /**
  * The projection operator extracts columns from a relation; unlike in
  * relational algebra, this operator does NOT eliminate duplicate tuples.
  */
 public class Projection extends Iterator {
+    private Iterator iterator;
+    private Integer[] fields;
+    private Schema projectingSchema;
+    private boolean isOpen;
 
     /**
      * Constructs a projection, given the underlying iterator and field numbers.
      */
     public Projection(Iterator aIter, Integer... aFields) {
-	  throw new UnsupportedOperationException("Not implemented");
+        this.iterator = aIter;
+        this.fields = aFields;
+
+        // We need to make a deep copy instead of referencing Iterator's.
+        // this.projectingSchema = this.iterator.getSchema();
+
+        Schema originalSchema = this.iterator.getSchema();
+        this.projectingSchema = new Schema(fields.length);
+
+        for (int i = 0; i < fields.length; i++) {
+            this.projectingSchema.initField(i, originalSchema.fieldType(fields[i]),
+                    originalSchema.fieldLength(fields[i]), originalSchema.fieldName(fields[i]));
+        }
+
+        this.isOpen = true;
     }
 
     /**
-   * Gives a one-line explanation of the iterator, repeats the call on any
+     * Gives a one-line explanation of the iterator, repeats the call on any child
-   * child iterators, and increases the indent depth along the way.
+     * iterators, and increases the indent depth along the way.
      */
     public void explain(int depth) {
         throw new UnsupportedOperationException("Not implemented");
@@ -26,28 +43,31 @@ public class Projection extends Iterator {
      * Restarts the iterator, i.e. as if it were just constructed.
      */
     public void restart() {
-	  throw new UnsupportedOperationException("Not implemented");
+        this.isOpen = false;
+        this.iterator.restart();
+        this.isOpen = true;
     }
 
     /**
      * Returns true if the iterator is open; false otherwise.
      */
     public boolean isOpen() {
-	  throw new UnsupportedOperationException("Not implemented");
+        return this.isOpen;
     }
 
     /**
      * Closes the iterator, releasing any resources (i.e. pinned pages).
      */
     public void close() {
-	  throw new UnsupportedOperationException("Not implemented");
+        this.iterator.close();
+        this.isOpen = false;
     }
 
     /**
      * Returns true if there are more tuples, false otherwise.
      */
     public boolean hasNext() {
-	  throw new UnsupportedOperationException("Not implemented");
+        return this.iterator.hasNext();
     }
 
     /**
@@ -56,7 +76,18 @@ public class Projection extends Iterator {
      * @throws IllegalStateException if no more tuples
      */
     public Tuple getNext() {
-	  throw new UnsupportedOperationException("Not implemented");
+        if (this.iterator.hasNext()) {
+            Tuple original = this.iterator.getNext();
+            Tuple projecting = new Tuple(this.projectingSchema);
+
+            for (int i = 0; i < this.fields.length; i++) {
+                projecting.setField(i, original.getField(this.fields[i]));
+            }
+
+            return projecting;
+        }
+
+        return new Tuple(new Schema(1));
     }
 
 } // public class Projection extends Iterator

p3/src/relop/Selection.java

@@ -6,17 +6,25 @@ package relop;
  * connected by OR operators.
  */
 public class Selection extends Iterator {
+    private Iterator iterator;
+    private Predicate[] predicates;
+    private Tuple currentTuple;
+    private boolean isOpen;
 
     /**
      * Constructs a selection, given the underlying iterator and predicates.
      */
     public Selection(Iterator aIter, Predicate... aPreds) {
-	  throw new UnsupportedOperationException("Not implemented");
+        this.iterator = aIter;
+        this.predicates = aPreds;
+        this.schema = this.iterator.schema;
+        this.isOpen = true;
+        this.currentTuple = null;
     }
 
     /**
-   * Gives a one-line explanation of the iterator, repeats the call on any
+     * Gives a one-line explanation of the iterator, repeats the call on any child
-   * child iterators, and increases the indent depth along the way.
+     * iterators, and increases the indent depth along the way.
      */
     public void explain(int depth) {
         throw new UnsupportedOperationException("Not implemented");
@@ -26,28 +34,50 @@ public class Selection extends Iterator {
      * Restarts the iterator, i.e. as if it were just constructed.
      */
     public void restart() {
-	  throw new UnsupportedOperationException("Not implemented");
+        this.isOpen = false;
+        this.iterator.restart();
+        this.isOpen = true;
     }
 
     /**
      * Returns true if the iterator is open; false otherwise.
      */
     public boolean isOpen() {
-	  throw new UnsupportedOperationException("Not implemented");
+        return this.isOpen;
     }
 
     /**
      * Closes the iterator, releasing any resources (i.e. pinned pages).
      */
     public void close() {
-	  throw new UnsupportedOperationException("Not implemented");
+        this.iterator.close();
+        this.isOpen = false;
     }
 
     /**
      * Returns true if there are more tuples, false otherwise.
      */
     public boolean hasNext() {
-	  throw new UnsupportedOperationException("Not implemented");
+        if (this.currentTuple != null) {
+            return true;
+        }
+
+        while (this.iterator.hasNext()) {
+            if (this.predicates.length == 0) {
+                return true;
+            }
+
+            this.currentTuple = iterator.getNext();
+
+            for (int i = 0; i < this.predicates.length; i++) {
+                if (this.predicates[i].evaluate(this.currentTuple)) {
+                    return true;
+                }
+            }
+        }
+
+        this.currentTuple = null;
+        return false;
     }
 
     /**
@@ -56,7 +86,28 @@ public class Selection extends Iterator {
      * @throws IllegalStateException if no more tuples
      */
     public Tuple getNext() {
-	  throw new UnsupportedOperationException("Not implemented");
+        if (this.currentTuple != null) {
+            Tuple tuple = this.currentTuple;
+            this.currentTuple = null;
+            return tuple;
+        }
+
+        while (this.iterator.hasNext()) {
+            Tuple tuple = this.iterator.getNext();
+            if (this.predicates.length == 0) {
+                return tuple;
+            }
+
+            this.currentTuple = iterator.getNext();
+
+            for (int i = 0; i < this.predicates.length; i++) {
+                if (this.predicates[i].evaluate(this.currentTuple)) {
+                    return tuple;
+                }
+            }
+        }
+
+        return null;
     }
 
 } // public class Selection extends Iterator

p3/src/relop/SimpleJoin.java

@@ -34,8 +34,8 @@ public class SimpleJoin extends Iterator {
     }
 
     /**
-	 * Gives a one-line explanation of the iterator, repeats the call on any
+     * Gives a one-line explanation of the iterator, repeats the call on any child
-	 * child iterators, and increases the indent depth along the way.
+     * iterators, and increases the indent depth along the way.
      */
     public void explain(int depth) {
 
@@ -109,15 +109,13 @@ public class SimpleJoin extends Iterator {
             if (outer.hasNext()) {
                 leftTuple = outer.getNext();
                 inner.restart();
-			}
+            } else
-			else
                 return false;
         }
     }
 
     /**
      * Gets the next tuple in the iteration.
-	 * 
      * @throws IllegalStateException if no more tuples
      */
     public Tuple getNext() {