Introducing updates (yay!)

src/main/java/org/rumbledb/api/Item.java

@@ -558,6 +558,35 @@ default void putItem(Item item) {
         throw new UnsupportedOperationException("Operation not defined for type " + this.getDynamicType());
     }
 
+    /**
+     * Add an item at index i, if it is an array.
+     *
+     * @param item an item.
+     * @param i an integer.
+     */
+    default void putItemAt(Item item, int i) {
+        throw new UnsupportedOperationException("Operation not defined for type " + this.getDynamicType());
+    }
+
+    /**
+     * Add all items in items at index i, if it is an array.
+     *
+     * @param items a list of items.
+     * @param i an integer.
+     */
+    default void putItemsAt(List<Item> items, int i) {
+        throw new UnsupportedOperationException("Operation not defined for type " + this.getDynamicType());
+    }
+
+    /**
+     * Remove the item at index i, if it is an array.
+     *
+     * @param i an integer.
+     */
+    default void removeItemAt(int i) {
+        throw new UnsupportedOperationException("Operation not defined for type " + this.getDynamicType());
+    }
+
     /**
      * Adds a value pair, if it is an array item.
      *
@@ -577,6 +606,15 @@ default void putItemByKey(String key, Item value) {
         throw new UnsupportedOperationException("Operation not defined for type " + this.getDynamicType());
     }
 
+    /**
+     * Removes a key-value pair, if it is an object item.
+     *
+     * @param key a key.
+     */
+    default void removeItemByKey(String key) {
+        throw new UnsupportedOperationException("Operation not defined for type " + this.getDynamicType());
+    }
+
     /**
      * Adds a key-value pair, if it is an object item. The value is lazily computed.
      *
@@ -648,6 +686,23 @@ default boolean isNaN() {
         throw new UnsupportedOperationException("Operation not defined for type " + this.getDynamicType());
     }
 
+    /**
+     * Returns the mutability level of the item.
+     *
+     * @return an int representing nestedness of the item inside transform expressions.
+     */
+    default int getMutabilityLevel() {
+        return 0;
+    }
+
+    /**
+     * Sets the mutability level of the item.
+     *
+     * @param mutabilityLevel the new mutability level.
+     */
+    default void setMutabilityLevel(int mutabilityLevel) {
+    }
+
     /**
      * Tests for logical equality. The semantics are that of the eq operator.
      *

src/main/java/org/rumbledb/api/Rumble.java

@@ -8,6 +8,7 @@
 import org.rumbledb.context.DynamicContext;
 import org.rumbledb.expressions.module.MainModule;
 import org.rumbledb.runtime.RuntimeIterator;
+import org.rumbledb.runtime.update.PendingUpdateList;
 import sparksoniq.spark.SparkSessionManager;
 
 /**
@@ -50,6 +51,14 @@ public SequenceOfItems runQuery(String query) {
             mainModule,
             this.configuration
         );
+
+        if (iterator.isUpdating()) {
+            PendingUpdateList pul = iterator.getPendingUpdateList(dynamicContext);
+            pul.applyUpdates(iterator.getMetadata());
+        }
+
+        System.err.println("final iterator is: " + iterator.isUpdating());
+
         return new SequenceOfItems(iterator, dynamicContext, this.configuration);
     }
 
@@ -70,6 +79,14 @@ public SequenceOfItems runQuery(URI location) throws IOException {
             mainModule,
             this.configuration
         );
+
+        if (iterator.isUpdating()) {
+            PendingUpdateList pul = iterator.getPendingUpdateList(dynamicContext);
+            pul.applyUpdates(iterator.getMetadata());
+        }
+
+        System.err.println("final iterator is: " + iterator.isUpdating());
+
         return new SequenceOfItems(iterator, dynamicContext, this.configuration);
     }
 

src/main/java/org/rumbledb/compiler/DynamicContextVisitor.java

@@ -113,6 +113,23 @@ public DynamicContext visitFunctionDeclaration(FunctionDeclaration declaration,
         return defaultAction(expression, argument);
     }
 
+    // @Override
+    // public DynamicContext visitTransformExpression(TransformExpression expression, DynamicContext argument) {
+    //
+    // for (CopyDeclaration copyDecl : expression.getCopyDeclarations()) {
+    // Expression child = copyDecl.getSourceExpression();
+    // this.visit(child, argument);
+    // RuntimeIterator iterator = VisitorHelpers.generateRuntimeIterator(child, this.configuration);
+    // iterator.bindToVariableInDynamicContext(argument, copyDecl.getVariableName(), argument);
+    // }
+    //
+    // this.visit(expression.getModifyExpression(), argument);
+    //
+    // this.visit(expression.getReturnExpression(), argument);
+    //
+    // return argument;
+    // }
+
     @Override
     public DynamicContext visitVariableDeclaration(VariableDeclaration variableDeclaration, DynamicContext argument) {
         Name name = variableDeclaration.getVariableName();

src/main/java/org/rumbledb/compiler/ExecutionModeVisitor.java

@@ -75,6 +75,8 @@
 import org.rumbledb.expressions.primary.VariableReferenceExpression;
 import org.rumbledb.expressions.typing.TreatExpression;
 import org.rumbledb.expressions.typing.ValidateTypeExpression;
+import org.rumbledb.expressions.update.CopyDeclaration;
+import org.rumbledb.expressions.update.TransformExpression;
 import org.rumbledb.items.ItemFactory;
 import org.rumbledb.runtime.misc.RangeOperationIterator;
 import org.rumbledb.types.BuiltinTypesCatalogue;
@@ -611,6 +613,25 @@ public StaticContext visitVariableDeclaration(VariableDeclaration variableDeclar
         return argument;
     }
 
+    @Override
+    public StaticContext visitTransformExpression(TransformExpression expression, StaticContext argument) {
+        StaticContext innerContext = expression.getStaticContext();
+        for (CopyDeclaration copyDecl : expression.getCopyDeclarations()) {
+            this.visit(copyDecl.getSourceExpression(), copyDecl.getSourceExpression().getStaticContext());
+            // first pass.
+            innerContext.setVariableStorageMode(
+                copyDecl.getVariableName(),
+                ExecutionMode.LOCAL
+            );
+        }
+        expression.setHighestExecutionMode(ExecutionMode.LOCAL);
+
+        this.visit(expression.getModifyExpression(), innerContext);
+        this.visit(expression.getReturnExpression(), innerContext);
+
+        return argument;
+    }
+
     @Override
     public StaticContext visitProlog(Prolog prolog, StaticContext argument) {
         visitDescendants(prolog, argument);