/*      $OpenBSD: tag.h,v 1.7 2015/11/19 07:53:31 bentley Exp $ */

/*-
 * Copyright (c) 1992, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1992, 1993, 1994, 1995, 1996
 *      Keith Bostic.  All rights reserved.
 * Copyright (c) 1994, 1996
 *      Rob Mayoff.  All rights reserved.
 *
 * See the LICENSE file for redistribution information.
 *
 *      @(#)tag.h       10.5 (Berkeley) 5/15/96
 */

/*
 * Tag file information.  One of these is maintained per tag file, linked
 * from the EXPRIVATE structure.
 */
struct _tagf {                  /* Tag files. */
        TAILQ_ENTRY(_tagf) q;   /* Linked list of tag files. */
        char    *name;          /* Tag file name. */
        int      errnum;        /* Errno. */

#define TAGF_ERR        0x01    /* Error occurred. */
#define TAGF_ERR_WARN   0x02    /* Error reported. */
        u_int8_t flags;
};

/*
 * Tags are structured internally as follows:
 *
 * +----+    +----+     +----+     +----+
 * | EP | -> | Q1 | <-- | T1 | <-- | T2 |
 * +----+    +----+ --> +----+ --> +----+
 *           |
 *           +----+     +----+
 *           | Q2 | <-- | T1 |
 *           +----+ --> +----+
 *           |
 *           +----+     +----+
 *           | Q3 | <-- | T1 |
 *           +----+ --> +----+
 *
 * Each Q is a TAGQ, or tag "query", which is the result of one tag.
 * Each Q references one or more TAG's, or tagged file locations.
 *
 * tag:         put a new Q at the head (^])
 * tagnext:     T1 -> T2 inside Q       (^N)
 * tagprev:     T2 -> T1 inside Q       (^P)
 * tagpop:      discard Q               (^T)
 * tagtop:      discard all Q
 */
struct _tag {                   /* Tag list. */
        TAILQ_ENTRY(_tag) q;    /* Linked list of tags. */

                                /* Tag pop/return information. */
        FREF    *frp;           /* Saved file. */
        recno_t  lno;           /* Saved line number. */
        size_t   cno;           /* Saved column number. */

        char    *fname;         /* Filename. */
        size_t   fnlen;         /* Filename length. */
        recno_t  slno;          /* Search line number. */
        char    *search;        /* Search string. */
        size_t   slen;          /* Search string length. */

        char     buf[1];        /* Variable length buffer. */
};

struct _tagq {                  /* Tag queue. */
        TAILQ_ENTRY(_tagq) q;   /* Linked list of tag queues. */
                                /* This queue's tag list. */
        TAILQ_HEAD(_tagqh, _tag) tagq;

        TAG     *current;       /* Current TAG within the queue. */

        char    *tag;           /* Tag string. */
        size_t   tlen;          /* Tag string length. */

        u_int8_t flags;

        char     buf[1];        /* Variable length buffer. */
};