+struct CYExpression;
+
+enum CYNeeded {
+ CYNever = -1,
+ CYSometimes = 0,
+ CYAlways = 1,
+};
+
+enum CYFlags {
+ CYNoFlags = 0,
+ CYNoBrace = (1 << 0),
+ CYNoFunction = (1 << 1),
+ CYNoIn = (1 << 2),
+ CYNoCall = (1 << 3),
+ CYNoRightHand = (1 << 4),
+ CYNoDangle = (1 << 5),
+ CYNoBF = (CYNoBrace | CYNoFunction),
+};
+
+struct CYContext {
+ apr_pool_t *pool_;
+
+ CYContext(apr_pool_t *pool) :
+ pool_(pool)
+ {
+ }
+
+ template <typename Type_>
+ void Replace(Type_ *&value) {
+ if (value != NULL)
+ while (Type_ *replace = value->Replace(*this))
+ value = replace;
+ }
+};
+
+struct CYStatement :
+ CYNext<CYStatement>
+{
+ void Single(CYOutput &out, CYFlags flags) const;
+ void Multiple(CYOutput &out, CYFlags flags = CYNoFlags) const;
+
+ CYStatement *ReplaceAll(CYContext &context);
+
+ virtual CYStatement *Replace(CYContext &context) = 0;
+
+ private:
+ virtual void Output(CYOutput &out, CYFlags flags) const = 0;
+};
+
+struct CYStatements {
+ CYStatement *first_;
+ CYStatement *last_;
+
+ CYStatements() :
+ first_(NULL),
+ last_(NULL)
+ {
+ }
+
+ operator CYStatement *() const {
+ return first_;
+ }
+
+ CYStatements &operator ->*(CYStatement *next) {
+ if (next != NULL)
+ if (first_ == NULL) {
+ first_ = next;
+ last_ = next;
+ } else for (;; last_ = last_->next_)
+ if (last_->next_ == NULL) {
+ last_->next_ = next;
+ last_ = next;
+ break;
+ }
+ return *this;
+ }
+};
+