CommonQuantifiedExpressionNode.java

package edu.udel.cis.vsl.abc.ast.node.common.expression;

import java.io.PrintStream;

import edu.udel.cis.vsl.abc.ast.IF.ASTException;
import edu.udel.cis.vsl.abc.ast.IF.DifferenceObject;
import edu.udel.cis.vsl.abc.ast.IF.DifferenceObject.DiffKind;
import edu.udel.cis.vsl.abc.ast.node.IF.ASTNode;
import edu.udel.cis.vsl.abc.ast.node.IF.PairNode;
import edu.udel.cis.vsl.abc.ast.node.IF.SequenceNode;
import edu.udel.cis.vsl.abc.ast.node.IF.declaration.VariableDeclarationNode;
import edu.udel.cis.vsl.abc.ast.node.IF.expression.ExpressionNode;
import edu.udel.cis.vsl.abc.ast.node.IF.expression.QuantifiedExpressionNode;
import edu.udel.cis.vsl.abc.token.IF.Source;

/**
 * A quantified expression consists of a quantifier, a variable bound by the
 * quantifier, an expression restricting the values of the quantified variable,
 * and a quantified expression. e.g. forall {int x | x > 1} x > 0;
 * 
 * @author zirkel
 * 
 */
public class CommonQuantifiedExpressionNode extends CommonExpressionNode
		implements
			QuantifiedExpressionNode {

	private Quantifier quantifier;

	/**
	 * @param source
	 *            The source code information for this expression.
	 * @param quantifier
	 *            The quantifier for this expression. One of {FORALL, EXISTS,
	 *            UNIFORM}.
	 * @param variableList
	 *            The list of bound variable declarations.
	 * @param restriction
	 *            Boolean-valued expression
	 * @param expression
	 *            the expression that is quantified
	 * @param intervalSequence
	 *            optional sequence of intervals used to specify domain of
	 *            uniform convergence for a $uniform expression; may be
	 *            <code>null</code>
	 */
	public CommonQuantifiedExpressionNode(Source source, Quantifier quantifier,
			SequenceNode<PairNode<SequenceNode<VariableDeclarationNode>, ExpressionNode>> variableList,
			ExpressionNode restriction, ExpressionNode expression,
			SequenceNode<PairNode<ExpressionNode, ExpressionNode>> intervalSequence) {
		super(source, variableList, restriction, expression, intervalSequence);
		this.quantifier = quantifier;
	}

	@Override
	public boolean isConstantExpression() {
		return false;
	}

	@Override
	public ExpressionNode copy() {
		return new CommonQuantifiedExpressionNode(this.getSource(), quantifier,
				duplicate(boundVariableList()), duplicate(restriction()),
				duplicate(expression()), duplicate(intervalSequence()));
	}

	@Override
	public Quantifier quantifier() {
		return quantifier;
	}

	@SuppressWarnings("unchecked")
	@Override
	public SequenceNode<PairNode<SequenceNode<VariableDeclarationNode>, ExpressionNode>> boundVariableList() {
		return (SequenceNode<PairNode<SequenceNode<VariableDeclarationNode>, ExpressionNode>>) this
				.child(0);
	}

	@Override
	public ExpressionNode restriction() {
		return (ExpressionNode) this.child(1);
	}

	@Override
	public ExpressionNode expression() {
		return (ExpressionNode) this.child(2);
	}

	@Override
	protected void printBody(PrintStream out) {
		String output = "";

		switch (quantifier) {
			case FORALL :
				output = "forall";
				break;
			case EXISTS :
				output = "exists";
				break;
			case UNIFORM :
				output = "uniform";
				break;
		}
		out.print(output);
	}

	@Override
	public ExpressionKind expressionKind() {
		return ExpressionKind.QUANTIFIED_EXPRESSION;
	}

	@Override
	public boolean isSideEffectFree(boolean errorsAreSideEffects) {
		boolean result = expression().isSideEffectFree(errorsAreSideEffects);

		if (restriction() != null)
			result = result && this.restriction()
					.isSideEffectFree(errorsAreSideEffects);
		return result;
	}

	@Override
	protected DifferenceObject diffWork(ASTNode that) {
		if (that instanceof QuantifiedExpressionNode) {
			QuantifiedExpressionNode thatQuan = (QuantifiedExpressionNode) that;

			if (this.quantifier == thatQuan.quantifier())
				return null;
			else
				return new DifferenceObject(this, that, DiffKind.OTHER,
						"different quantifier");
		}
		return new DifferenceObject(this, that);
	}

	@SuppressWarnings("unchecked")
	@Override
	public SequenceNode<PairNode<ExpressionNode, ExpressionNode>> intervalSequence() {
		return (SequenceNode<PairNode<ExpressionNode, ExpressionNode>>) this
				.child(3);
	}

	@Override
	public ASTNode setChild(int index, ASTNode child) {
		if (index >= 4)
			throw new ASTException(
					"CommonQuantifiedExpressionNode has four children, but saw index "
							+ index);
		switch (index) {
			case 0 :
				if (!(child == null || child instanceof SequenceNode))
					throw new ASTException(
							"Child of CommonQuantifiedExpressionNode at index "
									+ index
									+ " must be a SequenceNode, but saw "
									+ child + " with type " + child.nodeKind());
				break;
			case 1 :
				if (!(child == null || child instanceof ExpressionNode))
					throw new ASTException(
							"Child of CommonQuantifiedExpressionNode at index "
									+ index
									+ " must be a ExpressionNode, but saw "
									+ child + " with type " + child.nodeKind());
				break;
			case 2 :
				if (!(child == null || child instanceof ExpressionNode))
					throw new ASTException(
							"Child of CommonQuantifiedExpressionNode at index "
									+ index
									+ " must be a ExpressionNode, but saw "
									+ child + " with type " + child.nodeKind());
				break;
			case 3 :
				if (!(child == null || child instanceof SequenceNode))
					throw new ASTException(
							"Child of CommonQuantifiedExpressionNode at index "
									+ index
									+ " must be a SequenceNode, but saw "
									+ child + " with type " + child.nodeKind());
				break;
			default :
				break;
		}
		return super.setChild(index, child);
	}
}