updated for version 7.0001v7.0001

1 files changed, 3250 insertions, 0 deletions

diff --git a/src/fold.c b/src/fold.c
new file mode 100644
index 0000000000..ceac00bbf6
--- /dev/null
+++ b/src/fold.c
@@ -0,0 +1,3250 @@
+/* vim:set ts=8 sts=4 sw=4:
+ * vim600:fdm=marker fdl=1 fdc=3:
+ *
+ * VIM - Vi IMproved	by Bram Moolenaar
+ *
+ * Do ":help uganda"  in Vim to read copying and usage conditions.
+ * Do ":help credits" in Vim to see a list of people who contributed.
+ * See README.txt for an overview of the Vim source code.
+ */
+
+/*
+ * fold.c: code for folding
+ */
+
+#include "vim.h"
+
+#if defined(FEAT_FOLDING) || defined(PROTO)
+
+/* local declarations. {{{1 */
+/* typedef fold_T {{{2 */
+/*
+ * The toplevel folds for each window are stored in the w_folds growarray.
+ * Each toplevel fold can contain an array of second level folds in the
+ * fd_nested growarray.
+ * The info stored in both growarrays is the same: An array of fold_T.
+ */
+typedef struct
+{
+    linenr_T	fd_top;		/* first line of fold; for nested fold
+				 * relative to parent */
+    linenr_T	fd_len;		/* number of lines in the fold */
+    garray_T	fd_nested;	/* array of nested folds */
+    char	fd_flags;	/* see below */
+    char	fd_small;	/* TRUE, FALSE or MAYBE: fold smaller than
+				   'foldminlines'; MAYBE applies to nested
+				   folds too */
+} fold_T;
+
+#define FD_OPEN		0	/* fold is open (nested ones can be closed) */
+#define FD_CLOSED	1	/* fold is closed */
+#define FD_LEVEL	2	/* depends on 'foldlevel' (nested folds too) */
+
+#define MAX_LEVEL	20	/* maximum fold depth */
+
+/* static functions {{{2 */
+static void newFoldLevelWin __ARGS((win_T *wp));
+static int checkCloseRec __ARGS((garray_T *gap, linenr_T lnum, int level));
+static int foldFind __ARGS((garray_T *gap, linenr_T lnum, fold_T **fpp));
+static int foldLevelWin __ARGS((win_T *wp, linenr_T lnum));
+static void checkupdate __ARGS((win_T *wp));
+static void setFoldRepeat __ARGS((linenr_T lnum, long count, int open));
+static linenr_T setManualFold __ARGS((linenr_T lnum, int opening, int recurse, int *donep));
+static linenr_T setManualFoldWin __ARGS((win_T *wp, linenr_T lnum, int opening, int recurse, int *donep));
+static void foldOpenNested __ARGS((fold_T *fpr));
+static void deleteFoldEntry __ARGS((garray_T *gap, int idx, int recursive));
+static void foldMarkAdjustRecurse __ARGS((garray_T *gap, linenr_T line1, linenr_T line2, long amount, long amount_after));
+static int getDeepestNestingRecurse __ARGS((garray_T *gap));
+static int check_closed __ARGS((win_T *win, fold_T *fp, int *use_levelp, int level, int *maybe_smallp, linenr_T lnum_off));
+static void checkSmall __ARGS((win_T *wp, fold_T *fp, linenr_T lnum_off));
+static void setSmallMaybe __ARGS((garray_T *gap));
+static void foldCreateMarkers __ARGS((linenr_T start, linenr_T end));
+static void foldAddMarker __ARGS((linenr_T lnum, char_u *marker, int markerlen));
+static void deleteFoldMarkers __ARGS((fold_T *fp, int recursive, linenr_T lnum_off));
+static void foldDelMarker __ARGS((linenr_T lnum, char_u *marker, int markerlen));
+static void foldUpdateIEMS __ARGS((win_T *wp, linenr_T top, linenr_T bot));
+static void parseMarker __ARGS((win_T *wp));
+
+static char *e_nofold = N_("E490: No fold found");
+
+/*
+ * While updating the folds lines between invalid_top and invalid_bot have an
+ * undefined fold level.  Only used for the window currently being updated.
+ */
+static linenr_T invalid_top = (linenr_T)0;
+static linenr_T invalid_bot = (linenr_T)0;
+
+/*
+ * When using 'foldexpr' we sometimes get the level of the next line, which
+ * calls foldlevel() to get the level of the current line, which hasn't been
+ * stored yet.  To get around this chicken-egg problem the level of the
+ * previous line is stored here when available.  prev_lnum is zero when the
+ * level is not available.
+ */
+static linenr_T prev_lnum = 0;
+static int prev_lnum_lvl = -1;
+
+/* Flags used for "done" argument of setManualFold. */
+#define DONE_NOTHING	0
+#define DONE_ACTION	1	/* did close or open a fold */
+#define DONE_FOLD	2	/* did find a fold */
+
+static int foldstartmarkerlen;
+static char_u *foldendmarker;
+static int foldendmarkerlen;
+
+/* Exported folding functions. {{{1 */
+/* copyFoldingState() {{{2 */
+#if defined(FEAT_WINDOWS) || defined(PROTO)
+/*
+ * Copy that folding state from window "wp_from" to window "wp_to".
+ */
+    void
+copyFoldingState(wp_from, wp_to)
+    win_T	*wp_from;
+    win_T	*wp_to;
+{
+    wp_to->w_fold_manual = wp_from->w_fold_manual;
+    wp_to->w_foldinvalid = wp_from->w_foldinvalid;
+    cloneFoldGrowArray(&wp_from->w_folds, &wp_to->w_folds);
+}
+#endif
+
+/* hasAnyFolding() {{{2 */
+/*
+ * Return TRUE if there may be folded lines in the current window.
+ */
+    int
+hasAnyFolding(win)
+    win_T	*win;
+{
+    /* very simple now, but can become more complex later */
+    return (win->w_p_fen
+	    && (!foldmethodIsManual(win) || win->w_folds.ga_len > 0));
+}
+
+/* hasFolding() {{{2 */
+/*
+ * Return TRUE if line "lnum" in the current window is part of a closed
+ * fold.
+ * When returning TRUE, *firstp and *lastp are set to the first and last
+ * lnum of the sequence of folded lines (skipped when NULL).
+ */
+    int
+hasFolding(lnum, firstp, lastp)
+    linenr_T	lnum;
+    linenr_T	*firstp;
+    linenr_T	*lastp;
+{
+    return hasFoldingWin(curwin, lnum, firstp, lastp, TRUE, NULL);
+}
+
+/* hasFoldingWin() {{{2 */
+    int
+hasFoldingWin(win, lnum, firstp, lastp, cache, infop)
+    win_T	*win;
+    linenr_T	lnum;
+    linenr_T	*firstp;
+    linenr_T	*lastp;
+    int		cache;		/* when TRUE: use cached values of window */
+    foldinfo_T	*infop;		/* where to store fold info */
+{
+    int		had_folded = FALSE;
+    linenr_T	first = 0;
+    linenr_T	last = 0;
+    linenr_T	lnum_rel = lnum;
+    int		x;
+    fold_T	*fp;
+    int		level = 0;
+    int		use_level = FALSE;
+    int		maybe_small = FALSE;
+    garray_T	*gap;
+    int		low_level = 0;;
+
+    checkupdate(win);
+    /*
+     * Return quickly when there is no folding at all in this window.
+     */
+    if (!hasAnyFolding(win))
+    {
+	if (infop != NULL)
+	    infop->fi_level = 0;
+	return FALSE;
+    }
+
+    if (cache)
+    {
+	/*
+	 * First look in cached info for displayed lines.  This is probably
+	 * the fastest, but it can only be used if the entry is still valid.
+	 */
+	x = find_wl_entry(win, lnum);
+	if (x >= 0)
+	{
+	    first = win->w_lines[x].wl_lnum;
+	    last = win->w_lines[x].wl_lastlnum;
+	    had_folded = win->w_lines[x].wl_folded;
+	}
+    }
+
+    if (first == 0)
+    {
+	/*
+	 * Recursively search for a fold that contains "lnum".
+	 */
+	gap = &win->w_folds;
+	for (;;)
+	{
+	    if (!foldFind(gap, lnum_rel, &fp))
+		break;
+
+	    /* Remember lowest level of fold that starts in "lnum". */
+	    if (lnum_rel == fp->fd_top && low_level == 0)
+		low_level = level + 1;
+
+	    first += fp->fd_top;
+	    last += fp->fd_top;
+
+	    /* is this fold closed? */
+	    had_folded = check_closed(win, fp, &use_level, level,
+					       &maybe_small, lnum - lnum_rel);
+	    if (had_folded)
+	    {
+		/* Fold closed: Set last and quit loop. */
+		last += fp->fd_len - 1;
+		break;
+	    }
+
+	    /* Fold found, but it's open: Check nested folds.  Line number is
+	     * relative to containing fold. */
+	    gap = &fp->fd_nested;
+	    lnum_rel -= fp->fd_top;
+	    ++level;
+	}
+    }
+
+    if (!had_folded)
+    {
+	if (infop != NULL)
+	{
+	    infop->fi_level = level;
+	    infop->fi_lnum = lnum - lnum_rel;
+	    infop->fi_low_level = low_level == 0 ? level : low_level;
+	}
+	return FALSE;
+    }
+
+    if (lastp != NULL)
+	*lastp = last;
+    if (firstp != NULL)
+	*firstp = first;
+    if (infop != NULL)
+    {
+	infop->fi_level = level + 1;
+	infop->fi_lnum = first;
+	infop->fi_low_level = low_level == 0 ? level + 1 : low_level;
+    }
+    return TRUE;
+}
+
+/* foldLevel() {{{2 */
+/*
+ * Return fold level at line number "lnum" in the current window.
+ */
+    int
+foldLevel(lnum)
+    linenr_T	lnum;
+{
+    /* While updating the folds lines between invalid_top and invalid_bot have
+     * an undefined fold level.  Otherwise update the folds first. */
+    if (invalid_top == (linenr_T)0)
+	checkupdate(curwin);
+    else if (lnum == prev_lnum && prev_lnum_lvl >= 0)
+	return prev_lnum_lvl;
+    else if (lnum >= invalid_top && lnum <= invalid_bot)
+	return -1;
+
+    /* Return quickly when there is no folding at all in this window. */
+    if (!hasAnyFolding(curwin))
+	return 0;
+
+    return foldLevelWin(curwin, lnum);
+}
+
+/* lineFolded()	{{{2 */
+/*
+ * Low level function to check if a line is folded.  Doesn't use any caching.
+ * Return TRUE if line is folded.
+ * Return FALSE if line is not folded.
+ * Return MAYBE if the line is folded when next to a folded line.
+ */
+    int
+lineFolded(win, lnum)
+    win_T	*win;
+    linenr_T	lnum;
+{
+    return foldedCount(win, lnum, NULL) != 0;
+}
+
+/* foldedCount() {{{2 */
+/*
+ * Count the number of lines that are folded at line number "lnum".
+ * Normally "lnum" is the first line of a possible fold, and the returned
+ * number is the number of lines in the fold.
+ * Doesn't use caching from the displayed window.
+ * Returns number of folded lines from "lnum", or 0 if line is not folded.
+ * When "infop" is not NULL, fills *infop with the fold level info.
+ */
+    long
+foldedCount(win, lnum, infop)
+    win_T	*win;
+    linenr_T	lnum;
+    foldinfo_T	*infop;
+{
+    linenr_T	last;
+
+    if (hasFoldingWin(win, lnum, NULL, &last, FALSE, infop))
+	return (long)(last - lnum + 1);
+    return 0;
+}
+
+/* foldmethodIsManual() {{{2 */
+/*
+ * Return TRUE if 'foldmethod' is "manual"
+ */
+    int
+foldmethodIsManual(wp)
+    win_T	*wp;
+{
+    return (wp->w_p_fdm[3] == 'u');
+}
+
+/* foldmethodIsIndent() {{{2 */
+/*
+ * Return TRUE if 'foldmethod' is "indent"
+ */
+    int
+foldmethodIsIndent(wp)
+    win_T	*wp;
+{
+    return (wp->w_p_fdm[0] == 'i');
+}
+
+/* foldmethodIsExpr() {{{2 */
+/*
+ * Return TRUE if 'foldmethod' is "expr"
+ */
+    int
+foldmethodIsExpr(wp)
+    win_T	*wp;
+{
+    return (wp->w_p_fdm[1] == 'x');
+}
+
+/* foldmethodIsMarker() {{{2 */
+/*
+ * Return TRUE if 'foldmethod' is "marker"
+ */
+    int
+foldmethodIsMarker(wp)
+    win_T	*wp;
+{
+    return (wp->w_p_fdm[2] == 'r');
+}
+
+/* foldmethodIsSyntax() {{{2 */
+/*
+ * Return TRUE if 'foldmethod' is "syntax"
+ */
+    int
+foldmethodIsSyntax(wp)
+    win_T	*wp;
+{
+    return (wp->w_p_fdm[0] == 's');
+}
+
+/* foldmethodIsDiff() {{{2 */
+/*
+ * Return TRUE if 'foldmethod' is "diff"
+ */
+    int
+foldmethodIsDiff(wp)
+    win_T	*wp;
+{
+    return (wp->w_p_fdm[0] == 'd');
+}
+
+/* closeFold() {{{2 */
+/*
+ * Close fold for current window at line "lnum".
+ * Repeat "count" times.
+ */
+    void
+closeFold(lnum, count)
+    linenr_T	lnum;
+    long	count;
+{
+    setFoldRepeat(lnum, count, FALSE);
+}
+
+/* closeFoldRecurse() {{{2 */
+/*
+ * Close fold for current window at line "lnum" recursively.
+ */
+    void
+closeFoldRecurse(lnum)
+    linenr_T	lnum;
+{
+    (void)setManualFold(lnum, FALSE, TRUE, NULL);
+}
+
+/* opFoldRange() {{{2 */
+/*
+ * Open or Close folds for current window in lines "first" to "last".
+ * Used for "zo", "zO", "zc" and "zC" in Visual mode.
+ */
+    void
+opFoldRange(first, last, opening, recurse, had_visual)
+    linenr_T	first;
+    linenr_T	last;
+    int		opening;	/* TRUE to open, FALSE to close */
+    int		recurse;	/* TRUE to do it recursively */
+    int		had_visual;	/* TRUE when Visual selection used */
+{
+    int		done = DONE_NOTHING;	/* avoid error messages */
+    linenr_T	lnum;
+    linenr_T	lnum_next;
+
+    for (lnum = first; lnum <= last; lnum = lnum_next + 1)
+    {
+	lnum_next = lnum;
+	/* Opening one level only: next fold to open is after the one going to
+	 * be opened. */
+	if (opening && !recurse)
+	    (void)hasFolding(lnum, NULL, &lnum_next);
+	(void)setManualFold(lnum, opening, recurse, &done);
+	/* Closing one level only: next line to close a fold is after just
+	 * closed fold. */
+	if (!opening && !recurse)
+	    (void)hasFolding(lnum, NULL, &lnum_next);
+    }
+    if (done == DONE_NOTHING)
+	EMSG(_(e_nofold));
+#ifdef FEAT_VISUAL
+    /* Force a redraw to remove the Visual highlighting. */
+    if (had_visual)
+	redraw_curbuf_later(INVERTED);
+#endif
+}
+
+/* openFold() {{{2 */
+/*
+ * Open fold for current window at line "lnum".
+ * Repeat "count" times.
+ */
+    void
+openFold(lnum, count)
+    linenr_T	lnum;
+    long	count;
+{
+    setFoldRepeat(lnum, count, TRUE);
+}
+
+/* openFoldRecurse() {{{2 */
+/*
+ * Open fold for current window at line "lnum" recursively.
+ */
+    void
+openFoldRecurse(lnum)
+    linenr_T	lnum;
+{
+    (void)setManualFold(lnum, TRUE, TRUE, NULL);
+}
+
+/* foldOpenCursor() {{{2 */
+/*
+ * Open folds until the cursor line is not in a closed fold.
+ */
+    void
+foldOpenCursor()
+{
+    int		done;
+
+    checkupdate(curwin);
+    if (hasAnyFolding(curwin))
+	for (;;)
+	{
+	    done = DONE_NOTHING;
+	    (void)setManualFold(curwin->w_cursor.lnum, TRUE, FALSE, &done);
+	    if (!(done & DONE_ACTION))
+		break;
+	}
+}
+
+/* newFoldLevel() {{{2 */
+/*
+ * Set new foldlevel for current window.
+ */
+    void
+newFoldLevel()
+{
+    newFoldLevelWin(curwin);
+
+#ifdef FEAT_DIFF
+    if (foldmethodIsDiff(curwin) && curwin->w_p_scb)
+    {
+	win_T	    *wp;
+
+	/*
+	 * Set the same foldlevel in other windows in diff mode.
+	 */
+	FOR_ALL_WINDOWS(wp)
+	{
+	    if (wp != curwin && foldmethodIsDiff(wp) && wp->w_p_scb)
+	    {
+		wp->w_p_fdl = curwin->w_p_fdl;
+		newFoldLevelWin(wp);
+	    }
+	}
+    }
+#endif
+}
+
+    static void
+newFoldLevelWin(wp)
+    win_T	*wp;
+{
+    fold_T	*fp;
+    int		i;
+
+    checkupdate(wp);
+    if (wp->w_fold_manual)
+    {
+	/* Set all flags for the first level of folds to FD_LEVEL.  Following
+	 * manual open/close will then change the flags to FD_OPEN or
+	 * FD_CLOSED for those folds that don't use 'foldlevel'. */
+	fp = (fold_T *)wp->w_folds.ga_data;
+	for (i = 0; i < wp->w_folds.ga_len; ++i)
+	    fp[i].fd_flags = FD_LEVEL;
+	wp->w_fold_manual = FALSE;
+    }
+    changed_window_setting_win(wp);
+}
+
+/* foldCheckClose() {{{2 */
+/*
+ * Apply 'foldlevel' to all folds that don't contain the cursor.
+ */
+    void
+foldCheckClose()
+{
+    if (*p_fcl != NUL)	/* can only be "all" right now */
+    {
+	checkupdate(curwin);
+	if (checkCloseRec(&curwin->w_folds, curwin->w_cursor.lnum,
+							(int)curwin->w_p_fdl))
+	    changed_window_setting();
+    }
+}
+
+/* checkCloseRec() {{{2 */
+    static int
+checkCloseRec(gap, lnum, level)
+    garray_T	*gap;
+    linenr_T	lnum;
+    int		level;
+{
+    fold_T	*fp;
+    int		retval = FALSE;
+    int		i;
+
+    fp = (fold_T *)gap->ga_data;
+    for (i = 0; i < gap->ga_len; ++i)
+    {
+	/* Only manually opened folds may need to be closed. */
+	if (fp[i].fd_flags == FD_OPEN)
+	{
+	    if (level <= 0 && (lnum < fp[i].fd_top
+				      || lnum >= fp[i].fd_top + fp[i].fd_len))
+	    {
+		fp[i].fd_flags = FD_LEVEL;
+		retval = TRUE;
+	    }
+	    else
+		retval |= checkCloseRec(&fp[i].fd_nested, lnum - fp[i].fd_top,
+								   level - 1);
+	}
+    }
+    return retval;
+}
+
+/* foldCreateAllowed() {{{2 */
+/*
+ * Return TRUE if it's allowed to manually create or delete a fold.
+ * Give an error message and return FALSE if not.
+ */
+    int
+foldManualAllowed(create)
+    int		create;
+{
+    if (foldmethodIsManual(curwin) || foldmethodIsMarker(curwin))
+	return TRUE;
+    if (create)
+	EMSG(_("E350: Cannot create fold with current 'foldmethod'"));
+    else
+	EMSG(_("E351: Cannot delete fold with current 'foldmethod'"));
+    return FALSE;
+}
+
+/* foldCreate() {{{2 */
+/*
+ * Create a fold from line "start" to line "end" (inclusive) in the current
+ * window.
+ */
+    void
+foldCreate(start, end)
+    linenr_T	start;
+    linenr_T	end;
+{
+    fold_T	*fp;
+    garray_T	*gap;
+    garray_T	fold_ga;
+    int		i, j;
+    int		cont;
+    int		use_level = FALSE;
+    int		closed = FALSE;
+    int		level = 0;
+    linenr_T	start_rel = start;
+    linenr_T	end_rel = end;
+
+    if (start > end)
+    {
+	/* reverse the range */
+	end = start_rel;
+	start = end_rel;
+	start_rel = start;
+	end_rel = end;
+    }
+
+    /* When 'foldmethod' is "marker" add markers, which creates the folds. */
+    if (foldmethodIsMarker(curwin))
+    {
+	foldCreateMarkers(start, end);
+	return;
+    }
+
+    checkupdate(curwin);
+
+    /* Find the place to insert the new fold. */
+    gap = &curwin->w_folds;
+    for (;;)
+    {
+	if (!foldFind(gap, start_rel, &fp))
+	    break;
+	if (fp->fd_top + fp->fd_len > end_rel)
+	{
+	    /* New fold is completely inside this fold: Go one level deeper. */
+	    gap = &fp->fd_nested;
+	    start_rel -= fp->fd_top;
+	    end_rel -= fp->fd_top;
+	    if (use_level || fp->fd_flags == FD_LEVEL)
+	    {
+		use_level = TRUE;
+		if (level >= curwin->w_p_fdl)
+		    closed = TRUE;
+	    }
+	    else if (fp->fd_flags == FD_CLOSED)
+		closed = TRUE;
+	    ++level;
+	}
+	else
+	{
+	    /* This fold and new fold overlap: Insert here and move some folds
+	     * inside the new fold. */
+	    break;
+	}
+    }
+
+    i = (int)(fp - (fold_T *)gap->ga_data);
+    if (ga_grow(gap, 1) == OK)
+    {
+	fp = (fold_T *)gap->ga_data + i;
+	ga_init2(&fold_ga, (int)sizeof(fold_T), 10);
+
+	/* Count number of folds that will be contained in the new fold. */
+	for (cont = 0; i + cont < gap->ga_len; ++cont)
+	    if (fp[cont].fd_top > end_rel)
+		break;
+	if (cont > 0 && ga_grow(&fold_ga, cont) == OK)
+	{
+	    /* If the first fold starts before the new fold, let the new fold
+	     * start there.  Otherwise the existing fold would change. */
+	    if (start_rel > fp->fd_top)
+		start_rel = fp->fd_top;
+
+	    /* When last contained fold isn't completely contained, adjust end
+	     * of new fold. */
+	    if (end_rel < fp[cont - 1].fd_top + fp[cont - 1].fd_len - 1)
+		end_rel = fp[cont - 1].fd_top + fp[cont - 1].fd_len - 1;
+	    /* Move contained folds to inside new fold. */
+	    mch_memmove(fold_ga.ga_data, fp, sizeof(fold_T) * cont);
+	    fold_ga.ga_len += cont;
+	    fold_ga.ga_room -= cont;
+	    i += cont;
+
+	    /* Adjust line numbers in contained folds to be relative to the
+	     * new fold. */
+	    for (j = 0; j < cont; ++j)
+		((fold_T *)fold_ga.ga_data)[j].fd_top -= start_rel;
+	}
+	/* Move remaining entries to after the new fold. */
+	if (i < gap->ga_len)
+	    mch_memmove(fp + 1, (fold_T *)gap->ga_data + i,
+				     sizeof(fold_T) * (gap->ga_len - i));
+	gap->ga_len = gap->ga_len + 1 - cont;
+	gap->ga_room = gap->ga_room - 1 + cont;
+
+	/* insert new fold */
+	fp->fd_nested = fold_ga;
+	fp->fd_top = start_rel;
+	fp->fd_len = end_rel - start_rel + 1;
+
+	/* We want the new fold to be closed.  If it would remain open because
+	 * of using 'foldlevel', need to adjust fd_flags of containing folds.
+	 */
+	if (use_level && !closed && level < curwin->w_p_fdl)
+	    closeFold(start, 1L);
+	if (!use_level)
+	    curwin->w_fold_manual = TRUE;
+	fp->fd_flags = FD_CLOSED;
+	fp->fd_small = MAYBE;
+
+	/* redraw */
+	changed_window_setting();
+    }
+}
+
+/* deleteFold() {{{2 */
+/*
+ * Delete a fold at line "start" in the current window.
+ * When "end" is not 0, delete all folds from "start" to "end".
+ * When "recursive" is TRUE delete recursively.
+ */
+    void
+deleteFold(start, end, recursive, had_visual)
+    linenr_T	start;
+    linenr_T	end;
+    int		recursive;
+    int		had_visual;	/* TRUE when Visual selection used */
+{
+    garray_T	*gap;
+    fold_T	*fp;
+    garray_T	*found_ga;
+    fold_T	*found_fp = NULL;
+    linenr_T	found_off = 0;
+    int		use_level = FALSE;
+    int		maybe_small = FALSE;
+    int		level = 0;
+    linenr_T	lnum = start;
+    linenr_T	lnum_off;
+    int		did_one = FALSE;
+    linenr_T	first_lnum = MAXLNUM;
+    linenr_T	last_lnum = 0;
+
+    checkupdate(curwin);
+
+    while (lnum <= end)
+    {
+	/* Find the deepest fold for "start". */
+	gap = &curwin->w_folds;
+	found_ga = NULL;
+	lnum_off = 0;
+	for (;;)
+	{
+	    if (!foldFind(gap, lnum - lnum_off, &fp))
+		break;
+	    /* lnum is inside this fold, remember info */
+	    found_ga = gap;
+	    found_fp = fp;
+	    found_off = lnum_off;
+
+	    /* if "lnum" is folded, don't check nesting */
+	    if (check_closed(curwin, fp, &use_level, level,
+						      &maybe_small, lnum_off))
+		break;
+
+	    /* check nested folds */
+	    gap = &fp->fd_nested;
+	    lnum_off += fp->fd_top;
+	    ++level;
+	}
+	if (found_ga == NULL)
+	{
+	    ++lnum;
+	}
+	else
+	{
+	    lnum = found_fp->fd_top + found_fp->fd_len + found_off;
+	    did_one = TRUE;
+
+	    if (foldmethodIsManual(curwin))
+		deleteFoldEntry(found_ga,
+		    (int)(found_fp - (fold_T *)found_ga->ga_data), recursive);
+	    else
+	    {
+		if (found_fp->fd_top + found_off < first_lnum)
+		    first_lnum = found_fp->fd_top;
+		if (lnum > last_lnum)
+		    last_lnum = lnum;
+		parseMarker(curwin);
+		deleteFoldMarkers(found_fp, recursive, found_off);
+	    }
+
+	    /* redraw window */
+	    changed_window_setting();
+	}
+    }
+    if (!did_one)
+    {
+	EMSG(_(e_nofold));
+#ifdef FEAT_VISUAL
+	/* Force a redraw to remove the Visual highlighting. */
+	if (had_visual)
+	    redraw_curbuf_later(INVERTED);
+#endif
+    }
+    if (last_lnum > 0)
+	changed_lines(first_lnum, (colnr_T)0, last_lnum, 0L);
+}
+
+/* clearFolding() {{{2 */
+/*
+ * Remove all folding for window "win".
+ */
+    void
+clearFolding(win)
+    win_T	*win;
+{
+    deleteFoldRecurse(&win->w_folds);
+    win->w_foldinvalid = FALSE;
+}
+
+/* foldUpdate() {{{2 */
+/*
+ * Update folds for changes in the buffer of a window.
+ * Note that inserted/deleted lines must have already been taken care of by
+ * calling foldMarkAdjust().
+ * The changes in lines from top to bot (inclusive).
+ */
+    void
+foldUpdate(wp, top, bot)
+    win_T	*wp;
+    linenr_T	top;
+    linenr_T	bot;
+{
+    fold_T	*fp;
+
+    /* Mark all folds from top to bot as maybe-small. */
+    (void)foldFind(&curwin->w_folds, curwin->w_cursor.lnum, &fp);
+    while (fp < (fold_T *)curwin->w_folds.ga_data + curwin->w_folds.ga_len
+	    && fp->fd_top < bot)
+    {
+	fp->fd_small = MAYBE;
+	++fp;
+    }
+
+    if (foldmethodIsIndent(wp)
+	    || foldmethodIsExpr(wp)
+	    || foldmethodIsMarker(wp)
+#ifdef FEAT_DIFF
+	    || foldmethodIsDiff(wp)
+#endif
+	    || foldmethodIsSyntax(wp))
+	foldUpdateIEMS(wp, top, bot);
+}
+
+/* foldUpdateAll() {{{2 */
+/*
+ * Update all lines in a window for folding.
+ * Used when a fold setting changes or after reloading the buffer.
+ * The actual updating is postponed until fold info is used, to avoid doing
+ * every time a setting is changed or a syntax item is added.
+ */
+    void
+foldUpdateAll(win)
+    win_T	*win;
+{
+    win->w_foldinvalid = TRUE;
+    redraw_win_later(win, NOT_VALID);
+}
+
+/* foldMoveTo() {{{2 */
+/*
+ * If "updown" is FALSE: Move to the start or end of the fold.
+ * If "updown" is TRUE: move to fold at the same level.
+ * If not moved return FAIL.
+ */
+    int
+foldMoveTo(updown, dir, count)
+    int		updown;
+    int		dir;	    /* FORWARD or BACKWARD */
+    long	count;
+{
+    long	n;
+    int		retval = FAIL;
+    linenr_T	lnum_off;
+    linenr_T	lnum_found;
+    linenr_T	lnum;
+    int		use_level;
+    int		maybe_small;
+    garray_T	*gap;
+    fold_T	*fp;
+    int		level;
+    int		last;
+
+    /* Repeat "count" times. */
+    for (n = 0; n < count; ++n)
+    {
+	/* Find nested folds.  Stop when a fold is closed.  The deepest fold
+	 * that moves the cursor is used. */
+	lnum_off = 0;
+	gap = &curwin->w_folds;
+	use_level = FALSE;
+	maybe_small = FALSE;
+	lnum_found = curwin->w_cursor.lnum;
+	level = 0;
+	last = FALSE;
+	for (;;)
+	{
+	    if (!foldFind(gap, curwin->w_cursor.lnum - lnum_off, &fp))
+	    {
+		if (!updown)
+		    break;
+
+		/* When moving up, consider a fold above the cursor; when
+		 * moving down consider a fold below the cursor. */
+		if (dir == FORWARD)
+		{
+		    if (fp - (fold_T *)gap->ga_data >= gap->ga_len)
+			break;
+		    --fp;
+		}
+		else
+		{
+		    if (fp == (fold_T *)gap->ga_data)
+			break;
+		}
+		/* don't look for contained folds, they will always move
+		 * the cursor too far. */
+		last = TRUE;
+	    }
+
+	    if (!last)
+	    {
+		/* Check if this fold is closed. */
+		if (check_closed(curwin, fp, &use_level, level,
+						      &maybe_small, lnum_off))
+		    last = TRUE;
+
+		/* "[z" and "]z" stop at closed fold */
+		if (last && !updown)
+		    break;
+	    }
+
+	    if (updown)
+	    {
+		if (dir == FORWARD)
+		{
+		    /* to start of next fold if there is one */
+		    if (fp + 1 - (fold_T *)gap->ga_data < gap->ga_len)
+		    {
+			lnum = fp[1].fd_top + lnum_off;
+			if (lnum > curwin->w_cursor.lnum)
+			    lnum_found = lnum;
+		    }
+		}
+		else
+		{
+		    /* to end of previous fold if there is one */
+		    if (fp > (fold_T *)gap->ga_data)
+		    {
+			lnum = fp[-1].fd_top + lnum_off + fp[-1].fd_len - 1;
+			if (lnum < curwin->w_cursor.lnum)
+			    lnum_found = lnum;
+		    }
+		}
+	    }
+	    else
+	    {
+		/* Open fold found, set cursor to its start/end and then check
+		 * nested folds. */
+		if (dir == FORWARD)
+		{
+		    lnum = fp->fd_top + lnum_off + fp->fd_len - 1;
+		    if (lnum > curwin->w_cursor.lnum)
+			lnum_found = lnum;
+		}
+		else
+		{
+		    lnum = fp->fd_top + lnum_off;
+		    if (lnum < curwin->w_cursor.lnum)
+			lnum_found = lnum;
+		}
+	    }
+
+	    if (last)
+		break;
+
+	    /* Check nested folds (if any). */
+	    gap = &fp->fd_nested;
+	    lnum_off += fp->fd_top;
+	    ++level;
+	}
+	if (lnum_found != curwin->w_cursor.lnum)
+	{
+	    if (retval == FAIL)
+		setpcmark();
+	    curwin->w_cursor.lnum = lnum_found;
+	    curwin->w_cursor.col = 0;
+	    retval = OK;
+	}
+	else
+	    break;
+    }
+
+    return retval;
+}
+
+/* foldInitWin() {{{2 */
+/*
+ * Init the fold info in a new window.
+ */
+    void
+foldInitWin(newwin)
+    win_T	*newwin;
+{
+    ga_init2(&newwin->w_folds, (int)sizeof(fold_T), 10);
+}
+
+/* find_wl_entry() {{{2 */
+/*
+ * Find an entry in the win->w_lines[] array for buffer line "lnum".
+ * Only valid entries are considered (for entries where wl_valid is FALSE the
+ * line number can be wrong).
+ * Returns index of entry or -1 if not found.
+ */
+    int
+find_wl_entry(win, lnum)
+    win_T	*win;
+    linenr_T	lnum;
+{
+    int		i;
+
+    if (win->w_lines_valid > 0)
+	for (i = 0; i < win->w_lines_valid; ++i)
+	    if (win->w_lines[i].wl_valid)
+	    {
+		if (lnum < win->w_lines[i].wl_lnum)
+		    return -1;
+		if (lnum <= win->w_lines[i].wl_lastlnum)
+		    return i;
+	    }
+    return -1;
+}
+
+/* foldAdjustVisual() {{{2 */
+#ifdef FEAT_VISUAL
+/*
+ * Adjust the Visual area to include any fold at the start or end completely.
+ */
+    void
+foldAdjustVisual()
+{
+    pos_T	*start, *end;
+    char_u	*ptr;
+
+    if (!VIsual_active || !hasAnyFolding(curwin))
+	return;
+
+    if (ltoreq(VIsual, curwin->w_cursor))
+    {
+	start = &VIsual;
+	end = &curwin->w_cursor;
+    }
+    else
+    {
+	start = &curwin->w_cursor;
+	end = &VIsual;
+    }
+    if (hasFolding(start->lnum, &start->lnum, NULL))
+	start->col = 0;
+    if (hasFolding(end->lnum, NULL, &end->lnum))
+    {
+	ptr = ml_get(end->lnum);
+	end->col = (colnr_T)STRLEN(ptr);
+	if (end->col > 0 && *p_sel == 'o')
+	    --end->col;
+#ifdef FEAT_MBYTE
+	/* prevent cursor from moving on the trail byte */
+	if (has_mbyte)
+	    mb_adjust_cursor();
+#endif
+    }
+}
+#endif
+
+/* cursor_foldstart() {{{2 */
+/*
+ * Move the cursor to the first line of a closed fold.
+ */
+    void
+foldAdjustCursor()
+{
+    (void)hasFolding(curwin->w_cursor.lnum, &curwin->w_cursor.lnum, NULL);
+}
+
+/* Internal functions for "fold_T" {{{1 */
+/* cloneFoldGrowArray() {{{2 */
+/*
+ * Will "clone" (i.e deep copy) a garray_T of folds.
+ *
+ * Return FAIL if the operation cannot be completed, otherwise OK.
+ */
+    void
+cloneFoldGrowArray(from, to)
+    garray_T	*from;
+    garray_T	*to;
+{
+    int		i;
+    fold_T	*from_p;
+    fold_T	*to_p;
+
+    ga_init2(to, from->ga_itemsize, from->ga_growsize);
+    if (from->ga_len == 0 || ga_grow(to, from->ga_len) == FAIL)
+	return;
+
+    from_p = (fold_T *)from->ga_data;
+    to_p = (fold_T *)to->ga_data;
+
+    for (i = 0; i < from->ga_len; i++)
+    {
+	to_p->fd_top = from_p->fd_top;
+	to_p->fd_len = from_p->fd_len;
+	to_p->fd_flags = from_p->fd_flags;
+	to_p->fd_small = from_p->fd_small;
+	cloneFoldGrowArray(&from_p->fd_nested, &to_p->fd_nested);
+	++to->ga_len;
+	--to->ga_room;
+	++from_p;
+	++to_p;
+    }
+}
+
+/* foldFind() {{{2 */
+/*
+ * Search for line "lnum" in folds of growarray "gap".
+ * Set *fpp to the fold struct for the fold that contains "lnum" or
+ * the first fold below it (careful: it can be beyond the end of the array!).
+ * Returns FALSE when there is no fold that contains "lnum".
+ */
+    static int
+foldFind(gap, lnum, fpp)
+    garray_T	*gap;
+    linenr_T	lnum;
+    fold_T	**fpp;
+{
+    linenr_T	low, high;
+    fold_T	*fp;
+    int		i;
+
+    /*
+     * Perform a binary search.
+     * "low" is lowest index of possible match.
+     * "high" is highest index of possible match.
+     */
+    fp = (fold_T *)gap->ga_data;
+    low = 0;
+    high = gap->ga_len - 1;
+    while (low <= high)
+    {
+	i = (low + high) / 2;
+	if (fp[i].fd_top > lnum)
+	    /* fold below lnum, adjust high */
+	    high = i - 1;
+	else if (fp[i].fd_top + fp[i].fd_len <= lnum)
+	    /* fold above lnum, adjust low */
+	    low = i + 1;
+	else
+	{
+	    /* lnum is inside this fold */
+	    *fpp = fp + i;
+	    return TRUE;
+	}
+    }
+    *fpp = fp + low;
+    return FALSE;
+}
+
+/* foldLevelWin() {{{2 */
+/*
+ * Return fold level at line number "lnum" in window "wp".
+ */
+    static int
+foldLevelWin(wp, lnum)
+    win_T	*wp;
+    linenr_T	lnum;
+{
+    fold_T	*fp;
+    linenr_T	lnum_rel = lnum;
+    int		level =  0;
+    garray_T	*gap;
+
+    /* Recursively search for a fold that contains "lnum". */
+    gap = &wp->w_folds;
+    for (;;)
+    {
+	if (!foldFind(gap, lnum_rel, &fp))
+	    break;
+	/* Check nested folds.  Line number is relative to containing fold. */
+	gap = &fp->fd_nested;
+	lnum_rel -= fp->fd_top;
+	++level;
+    }
+
+    return level;
+}
+
+/* checkupdate() {{{2 */
+/*
+ * Check if the folds in window "wp" are invalid and update them if needed.
+ */
+    static void
+checkupdate(wp)
+    win_T	*wp;
+{
+    if (wp->w_foldinvalid)
+    {
+	foldUpdate(wp, (linenr_T)1, (linenr_T)MAXLNUM); /* will update all */
+	wp->w_foldinvalid = FALSE;
+    }
+}
+
+/* setFoldRepeat() {{{2 */
+/*
+ * Open or close fold for current window at line "lnum".
+ * Repeat "count" times.
+ */
+    static void
+setFoldRepeat(lnum, count, open)
+    linenr_T	lnum;
+    long	count;
+    int		open;
+{
+    int		done;
+    long	n;
+
+    for (n = 0; n < count; ++n)
+    {
+	done = DONE_NOT