support lookups via language servers (LSP)master-fmsbw-ci

* 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, 52 insertions, 12 deletions

diff --git a/src/view.c b/src/view.c
index 7a9e0cc..43cdd3f 100644
--- a/src/view.c
+++ b/src/view.c
@@ -47,13 +47,24 @@
 #include "eol.h"
 #include "memory.h"
 #include "lexer.h"
+#include "ring.h"
+#include "lsp.h"
 #include "view.h"
 
+//#define DEBUG
+
 /** @memberof teco_view_t */
 void
 teco_view_setup(teco_view_t *ctx)
 {
 	/*
+	 * Avoid unnecessary notifications.
+	 */
+	teco_view_ssm(ctx, SCI_SETCOMMANDEVENTS, FALSE, 0);
+	teco_view_ssm(ctx, SCI_SETMODEVENTMASK,
+	              SC_MOD_INSERTTEXT | SC_MOD_BEFOREDELETE, 0);
+
+	/*
 	 * Start with or without undo collection,
 	 * depending on teco_undo_enabled.
 	 */
@@ -825,20 +836,49 @@ teco_view_get_character(teco_view_t *ctx, gsize pos, gsize len)
 }
 
 void
-teco_view_process_notify(teco_view_t *ctx, SCNotification *notify)
+teco_view_process_notify(teco_view_t *ctx, const SCNotification *notify)
 {
 #ifdef DEBUG
-	g_printf("SCINTILLA NOTIFY: code=%d\n", notify->nmhdr.code);
+	g_printf("SCINTILLA NOTIFY: code=%u\n", notify->nmhdr.code);
 #endif
 
-	/*
-	 * Lexing in the container: only used for SciTECO.
-	 *
-	 * The "identifier" is abused to enable/disable lexing.
-	 * It could be extended later on for several internal lexers.
-	 * The alternative would be an ILexer5 wrapper, written in C++.
-	 */
-	if (notify->nmhdr.code == SCN_STYLENEEDED &&
-	    teco_view_ssm(ctx, SCI_GETIDENTIFIER, 0, 0) != 0)
-		teco_lexer_style(ctx, notify->position);
+	switch (notify->nmhdr.code) {
+	case SCN_STYLENEEDED:
+		/*
+		 * Lexing in the container: only used for SciTECO.
+		 *
+		 * The "identifier" is abused to enable/disable lexing.
+		 * It could be extended later on for several internal lexers.
+		 * The alternative would be an ILexer5 wrapper, written in C++.
+		 */
+		if (teco_view_ssm(ctx, SCI_GETIDENTIFIER, 0, 0) != 0)
+			teco_lexer_style(ctx, notify->position);
+		break;
+
+	case SCN_MODIFIED:
+#ifdef DEBUG
+		g_printf("SCINTILLA NOTIFY: modification=0x%02X\n", notify->modificationType);
+#endif
+
+		if (!teco_ring_current || ctx != teco_ring_current->view)
+			break;
+
+		if (notify->modificationType & SC_MOD_INSERTTEXT) {
+#ifdef DEBUG
+			g_printf("SCINTILLA NOTIFY: INSERT: pos=%ld, text=\"%.*s\"\n",
+			         notify->position, (gint)notify->length, notify->text);
+#endif
+			teco_lsp_didchange_insert(teco_ring_current, notify->position,
+			                          notify->length, notify->text, NULL);
+		}
+		if (notify->modificationType & SC_MOD_BEFOREDELETE) {
+#ifdef DEBUG
+			g_printf("SCINTILLA NOTIFY: BEFORE DELETE: pos=%ld, len=%ld\n",
+			         notify->position, notify->length);
+#endif
+			teco_lsp_didchange_delete(teco_ring_current, notify->position,
+			                          notify->length, NULL);
+		}
+		break;
+	}
 }