+++ /dev/null
-/* -*-c-*-
- *
- * Symbol table management
- *
- * (c) 1998 Straylight/Edgeware
- */
-
-/*----- Licensing notice --------------------------------------------------*
- *
- * This file is part of the mLib utilities library.
- *
- * mLib is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Library General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or (at your option) any later version.
- *
- * mLib is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public
- * License along with mLib; if not, write to the Free
- * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
- * MA 02111-1307, USA.
- */
-
-#ifndef MLIB_SYM_H
-#define MLIB_SYM_H
-
-#ifdef __cplusplus
- extern "C" {
-#endif
-
-/*----- Required headers --------------------------------------------------*/
-
-#include <stddef.h>
-
-#ifndef MLIB_BITS_H
-# include "bits.h"
-#endif
-
-#ifndef MLIB_HASH_H
-# include "hash.h"
-#endif
-
-#ifndef MLIB_SUB_H
-# include "sub.h"
-#endif
-
-/*----- Tuning parameters -------------------------------------------------*/
-
-/* --- Initial hash table size --- *
- *
- * This is the initial @mask@ value. It must be of the form %$2^n - 1$%,
- * so that it can be used to mask of the bottom bits of a hash value.
- */
-
-#define SYM_INITSZ 32 /* Size of a new hash table */
-
-/* --- Maximum load factor --- *
- *
- * This parameter controls how much the table has to be loaded before the
- * table is extended. The number of elements %$n$%, the number of bins %$b$%
- * and the limit %$l$% satisfy the relation %$n < bl$%; if a new item is
- * added to the table and this relation is found to be false, the table is
- * doubled in size.
- */
-
-#define SYM_LIMIT(n) ((n) * 2) /* Load factor for growing table */
-
-/*----- Type definitions --------------------------------------------------*/
-
-/* --- Symbol table --- *
- *
- * A @sym_table@ contains the information needed to manage a symbol table.
- * Users shouldn't fiddle with this information directly, but it needs to be
- * here so that objects of the correct type can be created.
- */
-
-typedef struct sym_table {
- hash_table t;
- subarena *s;
- size_t load;
-} sym_table;
-
-/* --- A symbol table entry --- *
- *
- * I don't care what actually gets stored in symbol entries because I don't
- * create them: that's the responsibility of my client. All I care about
- * here is that whatever gets passed to me is a structure whose first member
- * is a @sym_base@. The ANSI guarantees about structure layout are
- * sufficient to allow me to manipulate such objects.
- */
-
-typedef struct sym_base {
- hash_base b; /* Base structure */
- char *name; /* Pointer to name string */
- size_t len; /* Length of the symbol's name */
-} sym_base;
-
-/* --- Macros for picking out useful information --- *
- *
- * Note that @SYM_LEN@ returns the size of the symbol key. For textual keys,
- * this will include the terminating null.
- */
-
-#define SYM_NAME(sy) ((const char *)(((sym_base *)(sy))->name))
-#define SYM_LEN(sy) (((sym_base *)(sy))->len + 0)
-#define SYM_HASH(sy) (((sym_base *)(sy))->b.hash + 0)
-
-/* --- An iterator block --- */
-
-typedef struct { hash_iter i; } sym_iter;
-
-/*----- External functions ------------------------------------------------*/
-
-/* --- @sym_create@ --- *
- *
- * Arguments: @sym_table *t@ = symbol table to initialize
- *
- * Returns: ---
- *
- * Use: Initializes the given symbol table. Raises @EXC_NOMEM@ if
- * there isn't enough memory.
- */
-
-extern void sym_create(sym_table */*t*/);
-
-/* --- @sym_destroy@ --- *
- *
- * Arguments: @sym_table *t@ = pointer to symbol table in question
- *
- * Returns: ---
- *
- * Use: Destroys a symbol table, freeing all the memory it used to
- * occupy.
- */
-
-extern void sym_destroy(sym_table */*t*/);
-
-/* --- @sym_find@ --- *
- *
- * Arguments: @sym_table *t@ = pointer to symbol table in question
- * @const char *n@ = pointer to symbol name to look up
- * @long l@ = length of the name string or negative to measure
- * @size_t sz@ = size of desired symbol object, or zero
- * @unsigned *f@ = pointer to a flag, or null.
- *
- * Returns: The address of a @sym_base@ structure, or null if not found
- * and @sz@ is zero.
- *
- * Use: Looks up a symbol in a given symbol table. The name is
- * passed by the address of its first character. The length
- * may be given, in which case the name may contain arbitrary
- * binary data, or it may be given as a negative number, in
- * which case the length of the name is calculated as
- * @strlen(n) + 1@.
- *
- * The return value is the address of a pointer to a @sym_base@
- * block (which may have other things on the end, as above). If
- * the symbol could be found, the return value points to the
- * symbol block. If the symbol wasn't there, then if @sz@ is
- * nonzero, a new symbol is created and its address is returned;
- * otherwise a null pointer is returned. The exception
- * @EXC_NOMEM@ is raised if the block can't be allocated.
- *
- * The value of @*f@ indicates whether a new symbol entry was
- * created: a nonzero value indicates that an old value was
- * found.
- */
-
-extern void *sym_find(sym_table */*t*/, const char */*n*/, long /*l*/,
- size_t /*sz*/, unsigned */*f*/);
-
-/* --- @sym_remove@ --- *
- *
- * Arguments: @sym_table *t@ = pointer to a symbol table object
- * @void *b@ = pointer to symbol table entry
- *
- * Returns: ---
- *
- * Use: Removes the object from the symbol table. The space occupied
- * by the object and its name is freed; anything else attached
- * to the entry should already be gone by this point.
- */
-
-extern void sym_remove(sym_table */*t*/, void */*b*/);
-
-/* --- @sym_mkiter@ --- *
- *
- * Arguments: @sym_iter *i@ = pointer to an iterator object
- * @sym_table *t@ = pointer to a symbol table object
- *
- * Returns: ---
- *
- * Use: Creates a new symbol table iterator which may be used to
- * iterate through a symbol table.
- */
-
-#define SYM_MKITER(i_, t_) HASH_MKITER(&(i_)->i, &(t_)->t)
-
-extern void sym_mkiter(sym_iter */*i*/, sym_table */*t*/);
-
-/* --- @sym_next@ --- *
- *
- * Arguments: @sym_iter *i@ = pointer to iterator object
- *
- * Returns: Pointer to the next symbol found, or null when finished.
- *
- * Use: Returns the next symbol from the table. Symbols are not
- * returned in any particular order.
- */
-
-#define SYM_NEXT(i_, p) do { \
- hash_base *_q; \
- HASH_NEXT(&(i_)->i, _q); \
- (p) = (void *)_q; \
-} while (0)
-
-extern void *sym_next(sym_iter */*i*/);
-
-/*----- That's all, folks -------------------------------------------------*/
-
-#ifdef __cplusplus
- }
-#endif
-
-#endif
~mdw / mLib / blobdiff