feat(extmarks,ts,spell): full support for spelling

- Added 'spell' option to extmarks:

  Extmarks with this set will have the region spellchecked.

- Added 'noplainbuffer' option to 'spelloptions':

  This is used to tell Neovim not to spellcheck the buffer. The old
  behaviour was to spell check the whole buffer unless :syntax was set.

- Added spelling support to the treesitter highlighter:

  @spell captures in highlights.scm are used to define regions which
  should be spell checked.

- Added support for navigating spell errors for extmarks:

  Works for both ephemeral and static extmarks

- Added '_on_spell_nav' callback for decoration providers:

  Since ephemeral callbacks are only drawn for the visible screen,
  providers must implement this callback to instruct Neovim which
  regions in the buffer need can be spell checked.

  The callback takes a start position and an end position.

  Note: this callback is subject to change hence the _ prefix.

- Added spell captures for built-in support languages

Co-authored-by: Lewis Russell <lewis6991@gmail.com>
Co-authored-by: Björn Linse <bjorn.linse@gmail.com>

1 files changed, 30 insertions, 23 deletions

diff --git a/src/nvim/drawline.c b/src/nvim/drawline.c
index 85a0bf2f5f..7846510ad9 100644
--- a/src/nvim/drawline.c
+++ b/src/nvim/drawline.c
@@ -11,9 +11,11 @@
 
 #include "nvim/arabic.h"
 #include "nvim/buffer.h"
+#include "nvim/buffer_defs.h"
 #include "nvim/charset.h"
 #include "nvim/cursor.h"
 #include "nvim/cursor_shape.h"
+#include "nvim/decoration.h"
 #include "nvim/diff.h"
 #include "nvim/drawline.h"
 #include "nvim/fold.h"
@@ -654,7 +656,7 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool nochange,
 
     has_decor = decor_redraw_line(buf, lnum - 1, &decor_state);
 
-    providers_invoke_line(wp, providers, lnum - 1, &has_decor, provider_err);
+    decor_providers_invoke_line(wp, providers, lnum - 1, &has_decor, provider_err);
 
     if (*provider_err) {
       provider_err_virt_text(lnum, *provider_err);
@@ -1646,7 +1648,8 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool nochange,
       ptr++;
 
       if (extra_check) {
-        bool can_spell = true;
+        bool no_plain_buffer = (wp->w_s->b_p_spo_flags & SPO_NPBUFFER) != 0;
+        bool can_spell = !no_plain_buffer;
 
         // Get syntax attribute, unless still at the start of the line
         // (double-wide char that doesn't fit).
@@ -1698,6 +1701,29 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool nochange,
           char_attr = 0;
         }
 
+        if (has_decor && v > 0) {
+          bool selected = (area_active || (area_highlighting && noinvcur
+                                           && (colnr_T)vcol == wp->w_virtcol));
+          int extmark_attr = decor_redraw_col(wp->w_buffer, (colnr_T)v - 1, off,
+                                              selected, &decor_state);
+          if (extmark_attr != 0) {
+            if (!attr_pri) {
+              char_attr = hl_combine_attr(char_attr, extmark_attr);
+            } else {
+              char_attr = hl_combine_attr(extmark_attr, char_attr);
+            }
+          }
+
+          decor_conceal = decor_state.conceal;
+          if (decor_conceal && decor_state.conceal_char) {
+            decor_conceal = 2;  // really??
+          }
+
+          if (decor_state.spell) {
+            can_spell = true;
+          }
+        }
+
         // Check spelling (unless at the end of the line).
         // Only do this when there is no syntax highlighting, the
         // @Spell cluster is not used or the current syntax item
@@ -1706,9 +1732,9 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool nochange,
         if (has_spell && v >= word_end && v > cur_checked_col) {
           spell_attr = 0;
           if (!attr_pri) {
-            char_attr = syntax_attr;
+            char_attr = hl_combine_attr(char_attr, syntax_attr);
           }
-          if (c != 0 && (!has_syntax || can_spell)) {
+          if (c != 0 && ((!has_syntax && !no_plain_buffer) || can_spell)) {
             char_u *prev_ptr;
             char_u *p;
             int len;
@@ -1781,25 +1807,6 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool nochange,
           char_attr = hl_combine_attr(term_attrs[vcol], char_attr);
         }
 
-        if (has_decor && v > 0) {
-          bool selected = (area_active || (area_highlighting && noinvcur
-                                           && (colnr_T)vcol == wp->w_virtcol));
-          int extmark_attr = decor_redraw_col(wp->w_buffer, (colnr_T)v - 1, off,
-                                              selected, &decor_state);
-          if (extmark_attr != 0) {
-            if (!attr_pri) {
-              char_attr = hl_combine_attr(char_attr, extmark_attr);
-            } else {
-              char_attr = hl_combine_attr(extmark_attr, char_attr);
-            }
-          }
-
-          decor_conceal = decor_state.conceal;
-          if (decor_conceal && decor_state.conceal_char) {
-            decor_conceal = 2;  // really??
-          }
-        }
-
         // Found last space before word: check for line break.
         if (wp->w_p_lbr && c0 == c && vim_isbreak(c)
             && !vim_isbreak((int)(*ptr))) {