text: #ifndef _COMMON_H
  #define _COMMON_H 1
  
  #include <collections/stack.h>
  
  #include <stack_machine/context.h>
  
  #define DELIMITERS " \t\n"
  
  #define BUCKETS 256
  #define READLINE_BUFSIZ 256
  #define READLINE_HISTSIZ 100
  #define MEMSIZ 16384
  
  #define DEFAULT_BASE 10
  #define DEFAULT_ECHO 0
  #define CELL sizeof(int)
  
  #define true 1
  #define false 0
  
  #define align(x) (((int)x + (CELL - 1)) & ~(CELL - 1))
  extern int popnum(stack_t *stack, int *num);
  extern int peeknum(stack_t *stack, int *num);
  extern int pushnum(stack_t *stack, int num);
  extern int printnum(int num, int base);
  extern int parsenum(char *str, int *num, int base);
  #endif
  