regex/TRE/lib/tre-stack.h

   1 /*
   2   tre-stack.h: Stack definitions
   3
   4   This software is released under a BSD-style license.
   5   See the file LICENSE for details and copyright.
   6
   7 */
   8
   9
  10 #ifndef TRE_STACK_H
  11 #define TRE_STACK_H 1
  12
  13 #include "tre.h"
  14
  15 typedef struct tre_stack_rec tre_stack_t;
  16
  17 /* Creates a new stack object.  `size' is initial size in bytes, `max_size'
  18    is maximum size, and `increment' specifies how much more space will be
  19    allocated with realloc() if all space gets used up.  Returns the stack
  20    object or NULL if out of memory. */
  21 __private_extern__ tre_stack_t *
  22 tre_stack_new(int size, int max_size, int increment);
  23
  24 /* Frees the stack object. */
  25 __private_extern__ void
  26 tre_stack_destroy(tre_stack_t *s);
  27
  28 /* Returns the current number of objects in the stack. */
  29 __private_extern__ int
  30 tre_stack_num_objects(tre_stack_t *s);
  31
  32 /* Each tre_stack_push_*(tre_stack_t *s, <type> value) function pushes
  33    `value' on top of stack `s'.  Returns REG_ESPACE if out of memory.
  34    This tries to realloc() more space before failing if maximum size
  35    has not yet been reached.  Returns REG_OK if successful. */
  36 #define declare_pushf(typetag, type)                                          \
  37   __private_extern__ reg_errcode_t tre_stack_push_ ## typetag(tre_stack_t *s, \
  38                                                               type value)
  39
  40 declare_pushf(voidptr, void *);
  41 declare_pushf(int, int);
  42
  43 /* Each tre_stack_pop_*(tre_stack_t *s) function pops the topmost
  44    element off of stack `s' and returns it.  The stack must not be
  45    empty. */
  46 #define declare_popf(typetag, type)               \
  47   __private_extern__ type tre_stack_pop_ ## typetag(tre_stack_t *s)
  48
  49 declare_popf(voidptr, void *);
  50 declare_popf(int, int);
  51
  52 /* Just to save some typing. */
  53 #define STACK_PUSH(s, typetag, value)                                         \
  54   do                                                                          \
  55     {                                                                         \
  56       status = tre_stack_push_ ## typetag(s, value);                          \
  57     }                                                                         \
  58   while (/*CONSTCOND*/0)
  59
  60 #define STACK_PUSHX(s, typetag, value)                                        \
  61   {                                                                           \
  62     status = tre_stack_push_ ## typetag(s, value);                            \
  63     if (status != REG_OK)                                                     \
  64       break;                                                                  \
  65   }
  66
  67 #define STACK_PUSHR(s, typetag, value)                                        \
  68   {                                                                           \
  69     reg_errcode_t _status;                                                    \
  70     _status = tre_stack_push_ ## typetag(s, value);                           \
  71     if (_status != REG_OK)                                                    \
  72       return _status;                                                         \
  73   }
  74
  75 #endif /* TRE_STACK_H */
  76
  77 /* EOF */