expression.h

   1 #ifndef _EXPR_H
   2 #define _EXPR_H
   3
   4 #define DEBUG 1
   5
   6 enum {
   7     CONSTANT = 1,
   8     EVALUATED = 2
   9 };
  10
  11 typedef struct expression {
  12     char flags;
  13     double value;
  14     unsigned char op;
  15     struct expression *prev;
  16     struct expression *next;
  17     int precedence;
  18 } Expression;
  19
  20 int get_precedence(unsigned char op);
  21 double apply_operator(unsigned char op, double value1, double value2);
  22 double get_value(char *string);
  23
  24 void evaluate(Expression *expr);
  25 void finish_expression(Expression *expr, char *expression, unsigned char op, int precedence_factor);
  26 void print_expression(Expression *expr);
  27 #endif