Do not handle vertical lines as additional tbl(7) columns,

instead save their properties with the following column.
This simplifies layout parsing and saves a lot of code
related to column handling.

At output time, print all white space and vertical lines
separating columns before printing the following column,
and none after printing the preceding column, considerably
simplifying white space handling and width calculations.

No functional change, but it saves 150 lines of code,
and it allows the next patch to tbl_term.c, tbl_literal().

"Please check them in and I'll look into them later!" kristaps@

1 files changed, 35 insertions, 117 deletions

diff --git a/tbl_layout.c b/tbl_layout.c
index b2e7f3f3..618be8c6 100644
--- a/tbl_layout.c
+++ b/tbl_layout.c
@@ -1,6 +1,7 @@
 /*	$Id$ */
 /*
  * 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
@@ -51,8 +52,7 @@ static	const struct tbl_phrase keys[KEYS_MAX] = {
 	{ '^',		 TBL_CELL_DOWN },
 	{ '-',		 TBL_CELL_HORIZ },
 	{ '_',		 TBL_CELL_HORIZ },
-	{ '=',		 TBL_CELL_DHORIZ },
-	{ '|',		 TBL_CELL_VERT }
+	{ '=',		 TBL_CELL_DHORIZ }
 };
 
 static	int		 mods(struct tbl_node *, struct tbl_cell *, 
@@ -60,10 +60,8 @@ static	int		 mods(struct tbl_node *, struct tbl_cell *,
 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);
-static	void		 head_adjust(const struct tbl_cell *, 
-				struct tbl_head *);
+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, 
@@ -80,10 +78,6 @@ mods(struct tbl_node *tbl, struct tbl_cell *cp,
 	case (TBL_CELL_HORIZ):
 		/* FALLTHROUGH */
 	case (TBL_CELL_DHORIZ):
-		/* FALLTHROUGH */
-	case (TBL_CELL_VERT):
-		/* FALLTHROUGH */
-	case (TBL_CELL_DVERT):
 		return(1);
 	default:
 		break;
@@ -214,10 +208,17 @@ static int
 cell(struct tbl_node *tbl, struct tbl_row *rp, 
 		int ln, const char *p, int *pos)
 {
-	int		 i;
+	int		 vert, i;
 	enum tbl_cellt	 c;
 
-	/* Parse the column position (`r', `R', `|', ...). */
+	/* 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)
@@ -246,8 +247,6 @@ cell(struct tbl_node *tbl, struct tbl_row *rp,
 			return(0);
 		} else if (rp->last)
 			switch (rp->last->pos) {
-			case (TBL_CELL_VERT):
-			case (TBL_CELL_DVERT):
 			case (TBL_CELL_HORIZ):
 			case (TBL_CELL_DHORIZ):
 				mandoc_msg(MANDOCERR_TBLLAYOUT, tbl->parse,
@@ -270,25 +269,16 @@ cell(struct tbl_node *tbl, struct tbl_row *rp,
 
 	(*pos)++;
 
-	/* Extra check for the double-vertical. */
-
-	if (TBL_CELL_VERT == c && '|' == p[*pos]) {
-		(*pos)++;
-		c = TBL_CELL_DVERT;
-	} 
-	
 	/* Disallow adjacent spacers. */
 
-	if (rp->last && (TBL_CELL_VERT == c || TBL_CELL_DVERT == c) &&
-			(TBL_CELL_VERT == rp->last->pos || 
-			 TBL_CELL_DVERT == rp->last->pos)) {
+	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), ln, p, pos));
+	return(mods(tbl, cell_alloc(tbl, rp, c, vert), ln, p, pos));
 }
 
 
@@ -308,11 +298,11 @@ row:	/*
 	 */
 
 	rp = mandoc_calloc(1, sizeof(struct tbl_row));
-	if (tbl->last_row) {
+	if (tbl->last_row)
 		tbl->last_row->next = rp;
-		tbl->last_row = rp;
-	} else
-		tbl->last_row = tbl->first_row = rp;
+	else
+		tbl->first_row = rp;
+	tbl->last_row = rp;
 
 cell:
 	while (isspace((unsigned char)p[*pos]))
@@ -357,7 +347,8 @@ tbl_layout(struct tbl_node *tbl, int ln, const char *p)
 }
 
 static struct tbl_cell *
-cell_alloc(struct tbl_node *tbl, struct tbl_row *rp, enum tbl_cellt pos)
+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;
@@ -365,108 +356,35 @@ cell_alloc(struct tbl_node *tbl, struct tbl_row *rp, enum tbl_cellt pos)
 	p = mandoc_calloc(1, sizeof(struct tbl_cell));
 
 	if (NULL != (pp = rp->last)) {
-		rp->last->next = p;
-		rp->last = p;
-	} else
-		rp->last = rp->first = p;
+		pp->next = p;
+		h = pp->head->next;
+	} else {
+		rp->first = p;
+		h = tbl->first_head;
+	}
+	rp->last = p;
 
 	p->pos = pos;
+	p->vert = vert;
 
-	/*
-	 * This is a little bit complicated.  Here we determine the
-	 * header the corresponds to a cell.  We add headers dynamically
-	 * when need be or re-use them, otherwise.  As an example, given
-	 * the following:
-	 *
-	 * 	1  c || l 
-	 * 	2  | c | l
-	 * 	3  l l
-	 * 	3  || c | l |.
-	 *
-	 * We first add the new headers (as there are none) in (1); then
-	 * in (2) we insert the first spanner (as it doesn't match up
-	 * with the header); then we re-use the prior data headers,
-	 * skipping over the spanners; then we re-use everything and add
-	 * a last spanner.  Note that VERT headers are made into DVERT
-	 * ones.
-	 */
-
-	h = pp ? pp->head->next : tbl->first_head;
+	/* Re-use header. */
 
 	if (h) {
-		/* Re-use data header. */
-		if (TBL_HEAD_DATA == h->pos && 
-				(TBL_CELL_VERT != p->pos &&
-				 TBL_CELL_DVERT != p->pos)) {
-			p->head = h;
-			return(p);
-		}
-
-		/* Re-use spanner header. */
-		if (TBL_HEAD_DATA != h->pos && 
-				(TBL_CELL_VERT == p->pos ||
-				 TBL_CELL_DVERT == p->pos)) {
-			head_adjust(p, h);
-			p->head = h;
-			return(p);
-		}
-
-		/* Right-shift headers with a new spanner. */
-		if (TBL_HEAD_DATA == h->pos && 
-				(TBL_CELL_VERT == p->pos ||
-				 TBL_CELL_DVERT == p->pos)) {
-			hp = mandoc_calloc(1, sizeof(struct tbl_head));
-			hp->ident = tbl->opts.cols++;
-			hp->prev = h->prev;
-			if (h->prev)
-				h->prev->next = hp;
-			if (h == tbl->first_head)
-				tbl->first_head = hp;
-			h->prev = hp;
-			hp->next = h;
-			head_adjust(p, hp);
-			p->head = hp;
-			return(p);
-		}
-
-		if (NULL != (h = h->next)) {
-			head_adjust(p, h);
-			p->head = h;
-			return(p);
-		}
-
-		/* Fall through to default case... */
+		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;
-		tbl->last_head = hp;
 	} else
-		tbl->last_head = tbl->first_head = hp;
+		tbl->first_head = hp;
+	tbl->last_head = hp;
 
-	head_adjust(p, hp);
 	p->head = hp;
 	return(p);
 }
-
-static void
-head_adjust(const struct tbl_cell *cellp, struct tbl_head *head)
-{
-	if (TBL_CELL_VERT != cellp->pos &&
-			TBL_CELL_DVERT != cellp->pos) {
-		head->pos = TBL_HEAD_DATA;
-		return;
-	}
-
-	if (TBL_CELL_VERT == cellp->pos)
-		if (TBL_HEAD_DVERT != head->pos)
-			head->pos = TBL_HEAD_VERT;
-
-	if (TBL_CELL_DVERT == cellp->pos)
-		head->pos = TBL_HEAD_DVERT;
-}
-