1
Fork 0
mirror of git://git.sv.gnu.org/emacs.git synced 2025-12-15 18:40:39 -08:00

Add line-column tracking for tree-sitter

Add line-column tracking for tree-sitter parsers.  Copied from
comments in treesit.c:

   Technically we had to send tree-sitter the line and column
   position of each edit.  But in practice we just send it dummy
   values, because tree-sitter doesn't use it for parsing and
   mostly just carries the line and column positions around and
   return it when e.g. reporting node positions[1].  This has
   been working fine until we encountered grammars that actually
   utilizes the line and column information for
   parsing (Haskell)[2].

   [1] https://github.com/tree-sitter/tree-sitter/issues/445
   [2] https://github.com/tree-sitter/tree-sitter/issues/4001

   So now we have to keep track of line and column positions and
   pass valid values to tree-sitter.  (It adds quite some
   complexity, but only linearly; one can ignore all the linecol
   stuff when trying to understand treesit code and then come
   back to it later.)  Eli convinced me to disable tracking by
   default, and only enable it for languages that needs it.  So
   the buffer starts out not tracking linecol.  And when a
   parser is created, if the language is in
   treesit-languages-require-line-column-tracking, we enable
   tracking in the buffer, and enable tracking for the parser.
   To simplify things, once a buffer starts tracking linecol, it
   never disables tracking, even if parsers that need tracking
   are all deleted; and for parsers, tracking is determined at
   creation time, if it starts out tracking/non-tracking, it
   stays that way, regardless of later changes to
   treesit-languages-require-line-column-tracking.

   To make calculating line/column positons fast, we store
   linecol caches for begv, point, and zv in the
   buffer (buf->ts_linecol_cache_xxx); and in the parser object,
   we store linecol cache for visible beg/end of that parser.

   In buffer editing functions, we need the linecol for
   start/old_end/new_end, those can be calculated by scanning
   newlines (treesit_linecol_of_pos) from the buffer point
   cache, which should be always near the point.  And we usually
   set the calculated linecol of new_end back to the buffer
   point cache.

   We also need to calculate linecol for the visible_beg/end for
   each parser, and linecol for the buffer's begv/zv, these
   positions are usually far from point, so we have caches for
   all of them (in either the parser object or the buffer).
   These positions are far from point, so it's inefficient to
   scan newlines from point to there to get up-to-date linecol
   for them; but in the same time, because they're far and
   outside the changed region, we can calculate their change in
   line and column number by simply counting how much newlines
   are added/removed in the changed
   region (compute_new_linecol_by_change).

* doc/lispref/parsing.texi (Using Parser): Mention line-column
tracking in manual.
* etc/NEWS: Add news.
* lisp/treesit.el:
(treesit-languages-need-line-column-tracking): New variable.
* src/buffer.c: Include treesit.h (for TREESIT_EMPTY_LINECOL).
(Fget_buffer_create):
(Fmake_indirect_buffer): Initialize new buffer fields.
(Fbuffer_swap_text): Add new buffer fields.
* src/buffer.h (ts_linecol): New struct.
(buffer): New buffer fields.
(BUF_TS_LINECOL_BEGV):
(BUF_TS_LINECOL_POINT):
(BUF_TS_LINECOL_ZV):
(SET_BUF_TS_LINECOL_BEGV):
(SET_BUF_TS_LINECOL_POINT):
(SET_BUF_TS_LINECOL_ZV): New inline functions.
* src/casefiddle.c (casify_region): Record linecol info.
* src/editfns.c (Fsubst_char_in_region):
(Ftranslate_region_internal):
(Ftranspose_regions): Record linecol info.
* src/insdel.c (insert_1_both):
(insert_from_string_1):
(insert_from_gap_1):
(insert_from_buffer):
(replace_range):
(del_range_2): Record linecol info.
* src/treesit.c (TREESIT_BOB_LINECOL):
(TREESIT_EMPTY_LINECOL):
(TREESIT_TS_POINT_1_0): New constants.
(treesit_debug_print_linecol):
(treesit_buf_tracks_linecol_p):
(restore_restriction_and_selective_display):
(treesit_count_lines):
(treesit_debug_validate_linecol):
(treesit_linecol_of_pos):
(treesit_make_ts_point):
(Ftreesit_tracking_line_column_p):
(Ftreesit_parser_tracking_line_column_p): New functions.
(treesit_tree_edit_1): Accept real TSPoint and pass to
tree-sitter.
(compute_new_linecol_by_change): New function.
(treesit_record_change_1): Rename from treesit_record_change,
handle linecol if tracking is enabled.
(treesit_linecol_maybe): New function.
(treesit_record_change): New wrapper around
treesit_record_change_1 that handles some boilerplate and sets
buffer state.
(treesit_sync_visible_region): Handle linecol if tracking is
enabled.
(make_treesit_parser): Setup parser's linecol cache if tracking
is enabled.
(Ftreesit_parser_create): Enable tracking if the parser's
language requires it.
(Ftreesit__linecol_at):
(Ftreesit__linecol_cache_set):
(Ftreesit__linecol_cache): New functions for debugging and
testing.
(syms_of_treesit): New variable
Vtreesit_languages_require_line_column_tracking.
* src/treesit.h (Lisp_TS_Parser): New fields.
(TREESIT_BOB_LINECOL):
(TREESIT_EMPTY_LINECOL): New constants.
* test/src/treesit-tests.el (treesit-linecol-basic):
(treesit-linecol-search-back-across-newline):
(treesit-linecol-col-same-line):
(treesit-linecol-enable-disable): New tests.
* src/lisp.h: Declare display_count_lines.
* src/xdisp.c (display_count_lines): Remove static keyword.
This commit is contained in:
Yuan Fu 2025-03-18 17:26:26 -07:00
parent 159e3a981e
commit 1897da0b59
No known key found for this signature in database
GPG key ID: 56E19BC57664A442
13 changed files with 1086 additions and 69 deletions

View file

@ -4415,6 +4415,10 @@ extern void update_echo_area (void);
extern void truncate_echo_area (ptrdiff_t);
extern void redisplay (void);
extern ptrdiff_t count_lines (ptrdiff_t start_byte, ptrdiff_t end_byte);
extern ptrdiff_t display_count_lines (ptrdiff_t start_byte,
ptrdiff_t limit_byte,
ptrdiff_t count,
ptrdiff_t *byte_pos_ptr);
void set_frame_cursor_types (struct frame *, Lisp_Object);
extern void syms_of_xdisp (void);