/*

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Copyright 1992, 1993, 1994 Sun Microsystems, Inc.  Printed in the United
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This product is protected by copyright and distributed under the following
license restricting its use.

The Interface Definition Language Compiler Front End (CFE) is made
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notice on all media and documentation and the software program in which
this product is incorporated in whole or part. You may copy and extend
functionality (but may not remove functionality) of the Interface
Definition Language CFE without charge, but you are not authorized to
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program developed by you or with the express written consent of Sun
Microsystems, Inc. ("Sun").

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distribution of Interface Definition Language CFE as permitted herein.

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INTERFACE DEFINITION LANGUAGE CFE IS PROVIDED AS IS WITH NO WARRANTIES OF
ANY KIND INCLUDING THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS
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*/

#ifndef _AST_EXPRESSION_AST_EXPRESSION_HH
#define _AST_EXPRESSION_AST_EXPRESSION_HH

#include "StdString.h"

// Representation of expression values

class AST_Expression
{
public:

   // Enum to define all the different operators to combine expressions

   enum ExprComb 
   {
      EC_add  // '+'
      , EC_minus  // '-'
      , EC_mul  // '*'
      , EC_div  // '/'
      , EC_mod  // '%'
      , EC_or  // '|'
      , EC_xor  // '^'
      , EC_and  // '&'
      , EC_left  // '<<'
      , EC_right  // '>>'
      , EC_u_plus  // unary '+'
      , EC_u_minus // unary '-'
      , EC_bit_neg // '~'
      , EC_none  // No operator (missing)
      , EC_symbol  // a symbol (function or constant name)
   };

   // Enum to define the different kinds of evaluation possible
   // Extend this for more kinds of evaluation as required

   enum EvalKind 
   {
      EK_const,        // Must evaluate to constant
      EK_positive_int  // Must evaluate to positive integer
   };

   // Enum to define expression type

   enum ExprType 
   {
      EV_short   // Expression value is short
      , EV_ushort   // Expression value is unsigned short
      , EV_long   // Expression value is long
      , EV_ulong   // Expression value is unsigned long
      , EV_longlong  // Expression value is long long
      , EV_ulonglong  // Expression value is unsigned long long
      , EV_float   // Expression value is 32-bit float
      , EV_double   // Expression value is 64-bit float
      , EV_longdouble  // Expression value is 128-bit float
      , EV_char   // Expression value is char
      , EV_wchar   // Expression value is wide char
      , EV_octet   // Expression value is unsigned char
      , EV_bool   // Expression value is boolean
      , EV_string   // Expression value is char *
      , EV_wstring  // Expression value is wchar *
      , EV_any   // Expression value is any of above
      , EV_void   // Expression value is void (absent)
      , EV_none   // Expression value is missing
   };

   // Structure to describe value of constant expression and its type

   struct AST_ExprValue
   {
      union 
      {
         short sval; // Contains short expression value
         unsigned short usval; // Contains unsigned short expr value
         long lval; // Contains long expression value
         unsigned long ulval; // Contains unsigned long expr value
         unsigned long bval; // Contains boolean expression value
         float fval; // Contains 32-bit float expr value
         double dval; // Contains 64-bit float expr value
         char cval; // Contains char expression value
         wchar_t cwval; // Contains wchar expression value
         unsigned char oval; // Contains unsigned char expr value
         UTL_String *strval; // Contains String * expr value
         UTL_WString *wstrval; // Contains Wide String * expr value
         unsigned long eval; // Contains enumeration value
      } u;
      ExprType et;
   };

   // Constructors

   AST_Expression (AST_Expression *v, ExprType t);
   AST_Expression (ExprComb c, AST_Expression *v1, AST_Expression *v2);
   AST_Expression (short s);
   AST_Expression (unsigned short us);
   AST_Expression (long l);
   AST_Expression (long l, ExprType t);
   AST_Expression (unsigned long ul);
   AST_Expression (float f);
   AST_Expression (double d, const char * str);
   AST_Expression (char c);
   AST_Expression (unsigned char uc);
   AST_Expression (UTL_String *s);
   AST_Expression (UTL_WString *s);
   AST_Expression (UTL_ScopedName *n);

   virtual ~AST_Expression () {};

   // Data Accessors

   UTL_Scope *defined_in();
   void set_defined_in(UTL_Scope *d);
   long line();
   void set_line(long l);
   UTL_String *file_name();
   void set_file_name(UTL_String *f);
   ExprComb ec();
   void set_ec(ExprComb new_ec);
   AST_ExprValue *ev();
   void set_ev(AST_ExprValue *new_ev);
   AST_Expression *v1();
   void set_v1(AST_Expression *e);
   AST_Expression *v2();
   void set_v2(AST_Expression *e);
   UTL_ScopedName *n();
   void set_n(UTL_ScopedName *new_n);

   // AST Dumping

   virtual void dump(ostream &o);

   // Evaluation and value coercion

   virtual AST_ExprValue *eval(EvalKind ek);
   virtual AST_ExprValue *coerce(ExprType t);

   // Evaluate then store value inside this AST_Expression

   virtual void evaluate(EvalKind ek);

   // Compare to AST_Expressions

   virtual long operator==(AST_Expression *vc);
   virtual long compare(AST_Expression *vc);

   const char * expr_str ()
   {
      return (const char*) pd_expr;
   }

protected:

   // Evaluate different sets of operators

   virtual AST_ExprValue *eval_bin_op(EvalKind ek);
   virtual AST_ExprValue *eval_bit_op(EvalKind ek);
   virtual AST_ExprValue *eval_un_op(EvalKind ek);
   virtual AST_ExprValue *eval_symbol(EvalKind ek);

private:

   DDS_StdString pd_expr;
   UTL_Scope *pd_defined_in; // Scope
   long pd_line; // Line defined in
   UTL_String *pd_file_name; // What file defined in

   ExprComb pd_ec;  // What combinator
   AST_ExprValue *pd_ev;  // computed value
   AST_Expression *pd_v1;  // 1st sub-expression
   AST_Expression *pd_v2;  // 2nd sub-expression
   UTL_ScopedName *pd_n;  // symbolic name (if any)

   // Fill out the lineno, filename and definition scope details

   void fill_definition_details();

   // Internal evaluation

   virtual AST_ExprValue *eval_internal(EvalKind ek);
};

#endif           // _AST_EXPR_VAL_AST_EXPR_VAL_HH


