source: trunk/third/nvi/vi/v_paragraph.c @ 14302

/*-
 * 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.
 *
 * See the LICENSE file for redistribution information.
 */

#include "config.h"

#ifndef lint
static const char sccsid[] = "@(#)v_paragraph.c 10.7 (Berkeley) 3/6/96";
#endif /* not lint */

#include <sys/types.h>
#include <sys/queue.h>
#include <sys/time.h>

#include <bitstring.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "../common/common.h"
#include "vi.h"

#define INTEXT_CHECK {                                                  \
        if (len == 0 || v_isempty(p, len)) {                            \
                if (!--cnt)                                             \
                        goto found;                                     \
                pstate = P_INBLANK;                                     \
        }                                                               \
        /*                                                              \
         * !!!                                                          \
         * Historic documentation (USD:15-11, 4.2) said that formfeed   \
         * characters (^L) in the first column delimited paragraphs.    \
         * The historic vi code mentions formfeed characters, but never \
         * implements them.  It seems reasonable, do it.                \
         */                                                             \
        if (p[0] == '\014') {                                           \
                if (!--cnt)                                             \
                        goto found;                                     \
                continue;                                               \
        }                                                               \
        if (p[0] != '.' || len < 2)                                     \
                continue;                                               \
        for (lp = VIP(sp)->ps; *lp != '\0'; lp += 2)                    \
                if (lp[0] == p[1] &&                                    \
                    (lp[1] == ' ' && len == 2 || lp[1] == p[2]) &&      \
                    !--cnt)                                             \
                        goto found;                                     \
}

/*
 * v_paragraphf -- [count]}
 *      Move forward count paragraphs.
 *
 * Paragraphs are empty lines after text, formfeed characters, or values
 * from the paragraph or section options.
 *
 * PUBLIC: int v_paragraphf __P((SCR *, VICMD *));
 */
int
v_paragraphf(sp, vp)
        SCR *sp;
        VICMD *vp;
{
        enum { P_INTEXT, P_INBLANK } pstate;
        size_t lastlen, len;
        recno_t cnt, lastlno, lno;
        int isempty;
        char *p, *lp;

        /*
         * !!!
         * If the starting cursor position is at or before any non-blank
         * characters in the line, i.e. the movement is cutting all of the
         * line's text, the buffer is in line mode.  It's a lot easier to
         * check here, because we know that the end is going to be the start
         * or end of a line.
         *
         * This was historical practice in vi, with a single exception.  If
         * the paragraph movement was from the start of the last line to EOF,
         * then all the characters were deleted from the last line, but the
         * line itself remained.  If somebody complains, don't pause, don't
         * hesitate, just hit them.
         */
        if (ISMOTION(vp))
                if (vp->m_start.cno == 0)
                        F_SET(vp, VM_LMODE);
                else {
                        vp->m_stop = vp->m_start;
                        vp->m_stop.cno = 0;
                        if (nonblank(sp, vp->m_stop.lno, &vp->m_stop.cno))
                                return (1);
                        if (vp->m_start.cno <= vp->m_stop.cno)
                                F_SET(vp, VM_LMODE);
                }

        /* Figure out what state we're currently in. */
        lno = vp->m_start.lno;
        if (db_get(sp, lno, 0, &p, &len))
                goto eof;

        /*
         * If we start in text, we want to switch states
         * (2 * N - 1) times, in non-text, (2 * N) times.
         */
        cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
        cnt *= 2;
        if (len == 0 || v_isempty(p, len))
                pstate = P_INBLANK;
        else {
                --cnt;
                pstate = P_INTEXT;
        }

        for (;;) {
                lastlno = lno;
                lastlen = len;
                if (db_get(sp, ++lno, 0, &p, &len))
                        goto eof;
                switch (pstate) {
                case P_INTEXT:
                        INTEXT_CHECK;
                        break;
                case P_INBLANK:
                        if (len == 0 || v_isempty(p, len))
                                break;
                        if (--cnt) {
                                pstate = P_INTEXT;
                                break;
                        }
                        /*
                         * !!!
                         * Non-motion commands move to the end of the range,
                         * delete and yank stay at the start.  Ignore others.
                         * Adjust the end of the range for motion commands;
                         * historically, a motion component was to the end of
                         * the previous line, whereas the movement command was
                         * to the start of the new "paragraph".
                         */
found:                  if (ISMOTION(vp)) {
                                vp->m_stop.lno = lastlno;
                                vp->m_stop.cno = lastlen ? lastlen - 1 : 0;
                                vp->m_final = vp->m_start;
                        } else {
                                vp->m_stop.lno = lno;
                                vp->m_stop.cno = 0;
                                vp->m_final = vp->m_stop;
                        }
                        return (0);
                default:
                        abort();
                }
        }

        /*
         * !!!
         * Adjust end of the range for motion commands; EOF is a movement
         * sink.  The } command historically moved to the end of the last
         * line, not the beginning, from any position before the end of the
         * last line.  It also historically worked on empty files, so we
         * have to make it okay.
         */
eof:    if (vp->m_start.lno == lno || vp->m_start.lno == lno - 1) {
                if (db_eget(sp, vp->m_start.lno, &p, &len, &isempty)) {
                        if (!isempty)
                                return (1);
                        vp->m_start.cno = 0;
                        return (0);
                }
                if (vp->m_start.cno == (len ? len - 1 : 0)) {
                        v_eof(sp, NULL);
                        return (1);
                }
        }
        /*
         * !!!
         * Non-motion commands move to the end of the range, delete
         * and yank stay at the start.  Ignore others.
         *
         * If deleting the line (which happens if deleting to EOF), then
         * cursor movement is to the first nonblank.
         */
        if (ISMOTION(vp) && ISCMD(vp->rkp, 'd')) {
                F_CLR(vp, VM_RCM_MASK);
                F_SET(vp, VM_RCM_SETFNB);
        }
        vp->m_stop.lno = lno - 1;
        vp->m_stop.cno = len ? len - 1 : 0;
        vp->m_final = ISMOTION(vp) ? vp->m_start : vp->m_stop;
        return (0);
}

/*
 * v_paragraphb -- [count]{
 *      Move backward count paragraphs.
 *
 * PUBLIC: int v_paragraphb __P((SCR *, VICMD *));
 */
int
v_paragraphb(sp, vp)
        SCR *sp;
        VICMD *vp;
{
        enum { P_INTEXT, P_INBLANK } pstate;
        size_t len;
        recno_t cnt, lno;
        char *p, *lp;

        /*
         * !!!
         * Check for SOF.  The historic vi didn't complain if users hit SOF
         * repeatedly, unless it was part of a motion command.  There is no
         * question but that Emerson's editor of choice was vi.
         *
         * The { command historically moved to the beginning of the first
         * line if invoked on the first line.
         *
         * !!!
         * If the starting cursor position is in the first column (backward
         * paragraph movements did NOT historically pay attention to non-blank
         * characters) i.e. the movement is cutting the entire line, the buffer
         * is in line mode.  Cuts from the beginning of the line also did not
         * cut the current line, but started at the previous EOL.
         *
         * Correct for a left motion component while we're thinking about it.
         */
        lno = vp->m_start.lno;

        if (ISMOTION(vp))
                if (vp->m_start.cno == 0) {
                        if (vp->m_start.lno == 1) {
                                v_sof(sp, &vp->m_start);
                                return (1);
                        } else
                                --vp->m_start.lno;
                        F_SET(vp, VM_LMODE);
                } else
                        --vp->m_start.cno;

        if (vp->m_start.lno <= 1)
                goto sof;

        /* Figure out what state we're currently in. */
        if (db_get(sp, lno, 0, &p, &len))
                goto sof;

        /*
         * If we start in text, we want to switch states
         * (2 * N - 1) times, in non-text, (2 * N) times.
         */
        cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
        cnt *= 2;
        if (len == 0 || v_isempty(p, len))
                pstate = P_INBLANK;
        else {
                --cnt;
                pstate = P_INTEXT;

                /*
                 * !!!
                 * If the starting cursor is past the first column,
                 * the current line is checked for a paragraph.
                 */
                if (vp->m_start.cno > 0)
                        ++lno;
        }

        for (;;) {
                if (db_get(sp, --lno, 0, &p, &len))
                        goto sof;
                switch (pstate) {
                case P_INTEXT:
                        INTEXT_CHECK;
                        break;
                case P_INBLANK:
                        if (len != 0 && !v_isempty(p, len)) {
                                if (!--cnt)
                                        goto found;
                                pstate = P_INTEXT;
                        }
                        break;
                default:
                        abort();
                }
        }

        /* SOF is a movement sink. */
sof:    lno = 1;

found:  vp->m_stop.lno = lno;
        vp->m_stop.cno = 0;

        /*
         * All commands move to the end of the range.  (We already
         * adjusted the start of the range for motion commands).
         */
        vp->m_final = vp->m_stop;
        return (0);
}

/*
 * v_buildps --
 *      Build the paragraph command search pattern.
 *
 * PUBLIC: int v_buildps __P((SCR *, char *, char *));
 */
int
v_buildps(sp, p_p, s_p)
        SCR *sp;
        char *p_p, *s_p;
{
        VI_PRIVATE *vip;
        size_t p_len, s_len;
        char *p;

        /*
         * The vi paragraph command searches for either a paragraph or
         * section option macro.
         */
        p_len = p_p == NULL ? 0 : strlen(p_p);
        s_len = s_p == NULL ? 0 : strlen(s_p);

        if (p_len == 0 && s_len == 0)
                return (0);

        MALLOC_RET(sp, p, char *, p_len + s_len + 1);

        vip = VIP(sp);
        if (vip->ps != NULL)
                free(vip->ps);

        if (p_p != NULL)
                memmove(p, p_p, p_len + 1);
        if (s_p != NULL)
                memmove(p + p_len, s_p, s_len + 1);
        vip->ps = p;
        return (0);
}