private void consumeListExpression() {
	this.expressionPtr--;
	this.expressionLengthPtr--;
	Expression expr1 = this.expressionStack[this.expressionPtr];
	Expression expr2 = this.expressionStack[this.expressionPtr + 1];
			this.expressionStack[this.expressionPtr] =
				new ListExpression(
					expr1,
					expr2);

}