cmd/mandoc/tbl_layout.c

	tbl_layout.c revision 698f87a48e2e945bfe5493ce168e0d0ae1cedd5c
/*  $Id: tbl_layout.c,v 1.23 2012/05/27 17:54:54 schwarze Exp $ */
/*
 * Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 * Copyright (c) 2012 Ingo Schwarze <schwarze@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <assert.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#include "mandoc.h"
#include "libmandoc.h"
#include "libroff.h"

struct  tbl_phrase {
    char         name;
    enum tbl_cellt   key;
};

/*
 * FIXME: we can make this parse a lot nicer by, when an error is
 * encountered in a layout key, bailing to the next key (i.e. to the
 * next whitespace then continuing).
 */

#define KEYS_MAX     11

static  const struct tbl_phrase keys[KEYS_MAX] = {
    { 'c',       TBL_CELL_CENTRE },
    { 'r',       TBL_CELL_RIGHT },
    { 'l',       TBL_CELL_LEFT },
    { 'n',       TBL_CELL_NUMBER },
    { 's',       TBL_CELL_SPAN },
    { 'a',       TBL_CELL_LONG },
    { '^',       TBL_CELL_DOWN },
    { '-',       TBL_CELL_HORIZ },
    { '_',       TBL_CELL_HORIZ },
    { '=',       TBL_CELL_DHORIZ }
};

static  int      mods(struct tbl_node *, struct tbl_cell *,
                int, const char *, int *);
static  int      cell(struct tbl_node *, struct tbl_row *,
                int, const char *, int *);
static  void         row(struct tbl_node *, int, const char *, int *);
static  struct tbl_cell *cell_alloc(struct tbl_node *, struct tbl_row *,
                enum tbl_cellt, int vert);

static int
mods(struct tbl_node *tbl, struct tbl_cell *cp,
        int ln, const char *p, int *pos)
{
    char         buf[5];
    int      i;

    /* Not all types accept modifiers. */

    switch (cp->pos) {
    case (TBL_CELL_DOWN):
        /* FALLTHROUGH */
    case (TBL_CELL_HORIZ):
        /* FALLTHROUGH */
    case (TBL_CELL_DHORIZ):
        return(1);
    default:
        break;
    }

mod:
    /*
     * XXX: since, at least for now, modifiers are non-conflicting
     * (are separable by value, regardless of position), we let
     * modifiers come in any order.  The existing tbl doesn't let
     * this happen.
     */
    switch (p[*pos]) {
    case ('\0'):
        /* FALLTHROUGH */
    case (' '):
        /* FALLTHROUGH */
    case ('\t'):
        /* FALLTHROUGH */
    case (','):
        /* FALLTHROUGH */
    case ('.'):
        return(1);
    default:
        break;
    }

    /* Throw away parenthesised expression. */

    if ('(' == p[*pos]) {
        (*pos)++;
        while (p[*pos] && ')' != p[*pos])
            (*pos)++;
        if (')' == p[*pos]) {
            (*pos)++;
            goto mod;
        }
        mandoc_msg(MANDOCERR_TBLLAYOUT,
                tbl->parse, ln, *pos, NULL);
        return(0);
    }

    /* Parse numerical spacing from modifier string. */

    if (isdigit((unsigned char)p[*pos])) {
        for (i = 0; i < 4; i++) {
            if ( ! isdigit((unsigned char)p[*pos + i]))
                break;
            buf[i] = p[*pos + i];
        }
        buf[i] = '\0';

        /* No greater than 4 digits. */

        if (4 == i) {
            mandoc_msg(MANDOCERR_TBLLAYOUT, tbl->parse,
                    ln, *pos, NULL);
            return(0);
        }

        *pos += i;
        cp->spacing = (size_t)atoi(buf);

        goto mod;
        /* NOTREACHED */
    }

    /* TODO: GNU has many more extensions. */

    switch (tolower((unsigned char)p[(*pos)++])) {
    case ('z'):
        cp->flags |= TBL_CELL_WIGN;
        goto mod;
    case ('u'):
        cp->flags |= TBL_CELL_UP;
        goto mod;
    case ('e'):
        cp->flags |= TBL_CELL_EQUAL;
        goto mod;
    case ('t'):
        cp->flags |= TBL_CELL_TALIGN;
        goto mod;
    case ('d'):
        cp->flags |= TBL_CELL_BALIGN;
        goto mod;
    case ('w'):  /* XXX for now, ignore minimal column width */
        goto mod;
    case ('f'):
        break;
    case ('r'):
        /* FALLTHROUGH */
    case ('b'):
        /* FALLTHROUGH */
    case ('i'):
        (*pos)--;
        break;
    default:
        mandoc_msg(MANDOCERR_TBLLAYOUT, tbl->parse,
                ln, *pos - 1, NULL);
        return(0);
    }

    switch (tolower((unsigned char)p[(*pos)++])) {
    case ('3'):
        /* FALLTHROUGH */
    case ('b'):
        cp->flags |= TBL_CELL_BOLD;
        goto mod;
    case ('2'):
        /* FALLTHROUGH */
    case ('i'):
        cp->flags |= TBL_CELL_ITALIC;
        goto mod;
    case ('1'):
        /* FALLTHROUGH */
    case ('r'):
        goto mod;
    default:
        break;
    }

    mandoc_msg(MANDOCERR_TBLLAYOUT, tbl->parse,
            ln, *pos - 1, NULL);
    return(0);
}

static int
cell(struct tbl_node *tbl, struct tbl_row *rp,
        int ln, const char *p, int *pos)
{
    int      vert, i;
    enum tbl_cellt   c;

    /* Handle vertical lines. */

    for (vert = 0; '|' == p[*pos]; ++*pos)
        vert++;
    while (' ' == p[*pos])
        (*pos)++;

    /* Parse the column position (`c', `l', `r', ...). */

    for (i = 0; i < KEYS_MAX; i++)
        if (tolower((unsigned char)p[*pos]) == keys[i].name)
            break;

    if (KEYS_MAX == i) {
        mandoc_msg(MANDOCERR_TBLLAYOUT, tbl->parse,
                ln, *pos, NULL);
        return(0);
    }

    c = keys[i].key;

    /*
     * If a span cell is found first, raise a warning and abort the
     * parse.  If a span cell is found and the last layout element
     * isn't a "normal" layout, bail.
     *
     * FIXME: recover from this somehow?
     */

    if (TBL_CELL_SPAN == c) {
        if (NULL == rp->first) {
            mandoc_msg(MANDOCERR_TBLLAYOUT, tbl->parse,
                    ln, *pos, NULL);
            return(0);
        } else if (rp->last)
            switch (rp->last->pos) {
            case (TBL_CELL_HORIZ):
            case (TBL_CELL_DHORIZ):
                mandoc_msg(MANDOCERR_TBLLAYOUT, tbl->parse,
                        ln, *pos, NULL);
                return(0);
            default:
                break;
            }
    }

    /*
     * If a vertical spanner is found, we may not be in the first
     * row.
     */

    if (TBL_CELL_DOWN == c && rp == tbl->first_row) {
        mandoc_msg(MANDOCERR_TBLLAYOUT, tbl->parse, ln, *pos, NULL);
        return(0);
    }

    (*pos)++;

    /* Disallow adjacent spacers. */

    if (vert > 2) {
        mandoc_msg(MANDOCERR_TBLLAYOUT, tbl->parse, ln, *pos - 1, NULL);
        return(0);
    }

    /* Allocate cell then parse its modifiers. */

    return(mods(tbl, cell_alloc(tbl, rp, c, vert), ln, p, pos));
}


static void
row(struct tbl_node *tbl, int ln, const char *p, int *pos)
{
    struct tbl_row  *rp;

row:    /*
     * EBNF describing this section:
     *
     * row      ::= row_list [:space:]* [.]?[\n]
     * row_list ::= [:space:]* row_elem row_tail
     * row_tail ::= [:space:]*[,] row_list |
     *                  epsilon
     * row_elem ::= [\t\ ]*[:alpha:]+
     */

    rp = mandoc_calloc(1, sizeof(struct tbl_row));
    if (tbl->last_row)
        tbl->last_row->next = rp;
    else
        tbl->first_row = rp;
    tbl->last_row = rp;

cell:
    while (isspace((unsigned char)p[*pos]))
        (*pos)++;

    /* Safely exit layout context. */

    if ('.' == p[*pos]) {
        tbl->part = TBL_PART_DATA;
        if (NULL == tbl->first_row)
            mandoc_msg(MANDOCERR_TBLNOLAYOUT, tbl->parse,
                    ln, *pos, NULL);
        (*pos)++;
        return;
    }

    /* End (and possibly restart) a row. */

    if (',' == p[*pos]) {
        (*pos)++;
        goto row;
    } else if ('\0' == p[*pos])
        return;

    if ( ! cell(tbl, rp, ln, p, pos))
        return;

    goto cell;
    /* NOTREACHED */
}

int
tbl_layout(struct tbl_node *tbl, int ln, const char *p)
{
    int      pos;

    pos = 0;
    row(tbl, ln, p, &pos);

    /* Always succeed. */
    return(1);
}

static struct tbl_cell *
cell_alloc(struct tbl_node *tbl, struct tbl_row *rp, enum tbl_cellt pos,
        int vert)
{
    struct tbl_cell *p, *pp;
    struct tbl_head *h, *hp;

    p = mandoc_calloc(1, sizeof(struct tbl_cell));

    if (NULL != (pp = rp->last)) {
        pp->next = p;
        h = pp->head->next;
    } else {
        rp->first = p;
        h = tbl->first_head;
    }
    rp->last = p;

    p->pos = pos;
    p->vert = vert;

    /* Re-use header. */

    if (h) {
        p->head = h;
        return(p);
    }

    hp = mandoc_calloc(1, sizeof(struct tbl_head));
    hp->ident = tbl->opts.cols++;
    hp->vert = vert;

    if (tbl->last_head) {
        hp->prev = tbl->last_head;
        tbl->last_head->next = hp;
    } else
        tbl->first_head = hp;
    tbl->last_head = hp;

    p->head = hp;
    return(p);
}