private IFilterNode ParseFunctionExpression()
{
FilterToken function = Expect(FilterTokenType.Function);
var functionNode = new FunctionNode
{
FilterOperator = function.ToFilterOperator()
};
Expect(FilterTokenType.LeftParenthesis);
functionNode.Arguments.Add(Expression());
while (Is(FilterTokenType.Comma))
{
Expect(FilterTokenType.Comma);
functionNode.Arguments.Add(Expression());
}
Expect(FilterTokenType.RightParenthesis);
return functionNode;
}
private IFilterNode ParseComparisonExpression(IFilterNode firstArgument)
{
if (Is(FilterTokenType.ComparisonOperator))
{
FilterToken comparison = Expect(FilterTokenType.ComparisonOperator);
IFilterNode secondArgument = PrimaryExpression();
return new ComparisonNode
{
First = firstArgument,
FilterOperator = comparison.ToFilterOperator(),
Second = secondArgument
};
}
FilterToken function = Expect(FilterTokenType.Function);
var functionNode = new FunctionNode
{
FilterOperator = function.ToFilterOperator()
};
functionNode.Arguments.Add(firstArgument);
functionNode.Arguments.Add(PrimaryExpression());
return functionNode;
}