Initial import of the CDE 2.1.30 sources from the Open Group.

cde/programs/dtinfo/DtMmdb/StyleSheet/Expression.h

@@ -0,0 +1,154 @@
+/* $XConsortium: Expression.h /main/4 1996/08/21 15:50:17 drk $ */
+#ifndef _Expression_h
+#define _Expression_h
+
+/* **************************************************************
+   Defines the tree for evaluating expressions given as feature values
+   in the Style Sheet
+ * ************************************************************** */
+
+
+
+#include "SymTab.h"
+
+#ifndef CDE_NEXT
+
+typedef dlist_array<Symbol> f_items_t;
+#else
+#include "dti_cc/cc_povec.h"
+typedef dlist_array<Symbol> f_items_t;
+#endif
+
+
+class FeatureValue;
+class TermNode;
+
+// /////////////////////////////////////////////////////////////////////////
+// 	class Expression
+//
+//	holds root of expression tree 
+// /////////////////////////////////////////////////////////////////////////
+
+
+class Expression
+{
+public:
+  Expression(TermNode *root);
+  Expression(const Expression&);
+  ~Expression();
+
+  virtual FeatureValue *evaluate() const;
+  ostream &print(ostream &) const; 
+
+private:
+  TermNode* f_root;
+};
+
+class TermNode
+{
+public:
+  virtual ~TermNode();
+  virtual FeatureValue *evaluate() const = 0;
+  virtual ostream &print(ostream &) const = 0;
+  virtual TermNode *clone() const = 0;
+};
+
+class VariableNode: public TermNode
+{
+  // for single name variables eg: "DEFAULT_FONT" 
+public:
+  VariableNode(const Symbol& name);
+
+  virtual FeatureValue *evaluate() const;
+  ostream &print(ostream &) const;
+
+  virtual TermNode *clone() const;
+
+private:
+  Symbol f_name;
+
+};
+
+class CompositeVariableNode : public TermNode
+{
+  // for feature path variables (font.size)
+  // eg: font: { size: font.size }
+public:
+  CompositeVariableNode();
+  CompositeVariableNode(size_t capac); /* if we know how many items to expect */
+  ~CompositeVariableNode();
+
+  virtual FeatureValue *evaluate() const ;
+  ostream &print(ostream &) const;
+
+  virtual TermNode *clone() const;
+
+  void prependItem(const Symbol& item);
+  void appendItem(const Symbol& item);
+
+  const Symbol* convertableToVariable();
+
+private:
+  //dlist_array<Symbol>	f_items;
+  f_items_t f_items;
+};
+
+
+class BinaryOperatorNode: public TermNode
+{
+public:
+  enum operatorType { PLUS, MINUS, TIMES, DIVIDE };
+
+  BinaryOperatorNode(operatorType, TermNode* left, TermNode* right);
+  ~BinaryOperatorNode();
+
+  virtual TermNode *clone() const;
+
+  virtual FeatureValue *evaluate() const;
+  ostream &print(ostream &) const;
+
+
+private:
+  operatorType	f_operator ;
+  TermNode     *f_left;
+  TermNode     *f_right;
+
+};
+
+class SgmlAttributeNode: public TermNode
+{
+public:
+  SgmlAttributeNode(const Symbol& name);
+  SgmlAttributeNode();
+
+  virtual FeatureValue	*evaluate() const ;
+  ostream &print(ostream &) const;
+
+  virtual TermNode *clone() const;
+
+
+private:
+  Symbol      f_name;
+};
+
+class ConstantNode: public TermNode
+{
+public:
+  ConstantNode(FeatureValue*);
+  ~ConstantNode();
+  virtual FeatureValue *evaluate() const;
+  ostream &print(ostream &) const;
+
+  virtual TermNode *clone() const;
+
+private:
+  FeatureValue *f_value;
+
+};
+
+ostream &operator <<(ostream &, const Expression &);
+ostream &operator <<(ostream &, const TermNode &);
+
+
+#endif /* _Expression_h */
+/* DO NOT ADD ANY LINES AFTER THIS #endif */