support lookups via language servers (LSP)HEADmaster-fmsbw-cimaster

* The main interface is the `FT` command.
  `FT` was an undocumented Video TECO command for etags/ctags lookups.
  I don't want to exactly copy its interface, though.
* `FT` allows looking up symbol names,
  definitions and references.
* ctags will be supported via ctags-lsp.
  LSP support is more powerful though and works without
  regenerating TAGS files all the time.
  The LSP will also allow you to customize auto-completions
  using SciTECO itself (i.e. by writing a language server
  in SciTECO).
* For multiple results, `FT$` can be used to cycle through
  results - this should mimic repeated `S$` or `N$`.
* `:FT...$` does a fuzzy search. IMHO it's not important
  to return a status integer instead. `FT` will only
  really be used in interactive mode.
* Document synchronization is supported via hooks from
  ring.c and via Scintilla notifications.
* Currently, the LSP communication is based on blocking
  GIOChannels. This means that a misbehaving hanging
  server could "lock up" the entire editor (FIXME).
  Only on ncurses you can always kill the subprocess by
  pressing CTRL+C.
  We need helper functions in spawn.c to read and write
  with interruptions.
* The textDocument/didChange notification transmits
  not only all edits, but all files' contents as well
  during initial synchronization.
  Therefore it is optimized to write and JSON-escape
  data without copying them around in memory and without
  destroying the buffer gap.
* Use $SCITECO_LSP to configure the language server.
  You can also use `tee` to capture stdin and stdout.
  Perhaps $SCITECO_LSP should be saved in .teco_session,
  so you can change it between projects?
* $SCITECO_LSP_ROOT is used to point to the project's
  root directory. session.tes will set it up automatically.

1 files changed, 35 insertions, 0 deletions

diff --git a/src/lsp.h b/src/lsp.h
new file mode 100644
index 0000000..325c204
--- /dev/null
+++ b/src/lsp.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2012-2026 Robin Haberkorn
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+
+#include <glib.h>
+
+#include "parser.h"
+#include "ring.h"
+
+gboolean teco_lsp_didopen(teco_buffer_t *buffer, GError **error);
+gboolean teco_lsp_didchange_insert(teco_buffer_t *buffer, gsize pos, gsize len,
+                                   const gchar *text, GError **error);
+gboolean teco_lsp_didchange_delete(teco_buffer_t *buffer, gsize pos, gsize len,
+                                   GError **error);
+gboolean teco_lsp_didclose(teco_buffer_t *buffer, GError **error);
+
+gboolean teco_lsp_sync(teco_buffer_t *buffer, GError **error);
+
+gboolean teco_lsp_symbol_auto_complete(const gchar *symbol, teco_string_t *insert);
+
+extern teco_state_t teco_state_lsp_lookup;