The QueryExpression class serves as an abstract base class for the abstract syntax tree nodes used in Filter expressions. More...

Classes
class	Visitor
	The QueryExpression visitor base class. More...

Public Types
enum	OpCode { Compare = 1, Not, And, Or, Equals, HasAnyTag, HasAllTags, HasTags, StringContains }
	The boolean expression OpCodes supported by StateServer's query expression (filter) evaluator. More...

Detailed Description

The QueryExpression class serves as an abstract base class for the abstract syntax tree nodes used in Filter expressions.

In particular, it hosts the QueryExpression::Visitor class which is used to implement a visitor pattern for walking the tree.

Member Enumeration Documentation

The boolean expression OpCodes supported by StateServer's query expression (filter) evaluator.

Enumerator
Compare	Compare a property spec value with a query spec value. The server expects that the Type of the query spec value is exactly the same as the property spec value. Any widening or narrowing type conversions required to convert the query spec value to match the type of the property spec value should be done on the client when constructing the query spec.
Not	Negate the boolean expression following the Not OpCode.
And	Perform the logical AND of the two boolean expressions that follow.
Or	Perform the logical OR of the two boolean expressions that follow.
Equals	Compare the result values of two boolean expressions for equality.
HasAnyTag	Return `true` if any query spec tag bits are in the property spec tag bits.
HasAllTags	Return `true` if all query spec tag bits are in property spec tag bits.
HasTags	Return `true` if the tag bits specified by a mask are identically set/not set in the property tags and query tags.
StringContains	Returns `true` if the first (string) operand contains the second (string) operand.

virtual void sosscli::QueryExpression::accept ( Visitor & v) const

pure virtual

Abstract member method.

QueryExpression subclasses each implement this method as

void accept(Visitor &v)
{
 v.visit(*this);
}

Thus, the appropriate overload of QueryExpression::Vistor::visit is called, passing the QueryExpression node to the visitor.

Parameters

v	The QueryExpression::Visitor visitor instance.

The documentation for this class was generated from the following file: