/*----------------------------------------------------------------------
  File    : symtab.h
  Contents: symbol table management
  Author  : Christian Borgelt
  History : 22.10.1995 file created
            30.10.1995 functions made independent of symbol data
            26.11.1995 symbol types and visibility levels added
            04.01.1996 st_clear added
            27.02.1996 st_insert modified, st_name and st_type added
            26.03.1996 insertion into hash bucket simplified
            28.06.1996 dynamic bucket vector enlargement added
            01.04.1997 functions st_clear and st_remove combined
            31.05.1998 list of all symbols removed
            20.06.1998 deletion function moved to st_create
            28.09.1998 types ULONG and CCHAR removed, st_stats added
            04.02.1999 long int changed to int
----------------------------------------------------------------------*/
#ifndef __SYMTAB__
#define __SYMTAB__

/*----------------------------------------------------------------------
  Preprocessor Definitions
----------------------------------------------------------------------*/
#define EXISTS  ((void*)-1)     /* symbol exists already */

/*----------------------------------------------------------------------
  Type Definitions
----------------------------------------------------------------------*/
typedef unsigned int HASHFN (const char *s, int type);
typedef void         SYMFN  (void *data);

typedef struct _ste {           /* --- symbol table element --- */
  struct _ste *succ;            /* successor in hash bucket */
  char        *name;            /* symbol name */
  int         type;             /* symbol type */
  int         level;            /* visibility level */
} STE;                          /* (symbol table element) */

typedef struct {                /* --- symbol table --- */
  int         cnt;              /* current number of symbols */
  int         level;            /* current visibility level */
  int         size;             /* current hash table size */
  int         max;              /* maximal hash table size */
  HASHFN      *hash;            /* hash function */
  SYMFN       *delfn;           /* symbol deletion function */
  STE         **bvec;           /* bucket vector */
} SYMTAB;                       /* (symbol table) */

/*----------------------------------------------------------------------
  Functions
----------------------------------------------------------------------*/
extern SYMTAB*     st_create (int init, int max,
                              HASHFN hash, SYMFN delfn);
extern void        st_delete (SYMTAB *tab);
extern void*       st_insert (SYMTAB *tab, const char *name, int type,
                              unsigned int size);
extern int         st_remove (SYMTAB *tab, const char *name, int type);
extern void*       st_lookup (SYMTAB *tab, const char *name, int type);
extern void        st_begblk (SYMTAB *tab);
extern void        st_endblk (SYMTAB *tab);
extern int         st_symcnt (const SYMTAB *tab);
extern const char* st_name   (const void *data);
extern int         st_type   (const void *data);
#ifndef NDEBUG
extern void        st_stats  (const SYMTAB *tab);
#endif

/*----------------------------------------------------------------------
  Preprocessor Definitions
----------------------------------------------------------------------*/
#define st_begblk(t)     ((t)->level++)
#define st_symcnt(t)     ((t)->cnt)
#define st_name(d)       ((const char*)((STE*)(d)-1)->name)
#define st_type(d)       (((STE*)(d)-1)->type)

#endif