implemented Scintilla lexer for SciTECO code, i.e. TECO syntax highlighting

* this works by embedding the SciTECO parser and driving it always (exclusively)
  in parse-only mode.
* A new teco_state_t::style determines the Scintilla style for any character
  accepted in the given state.
* Therefore, the SciTECO lexer is always 100% exact and corresponds to the current
  SciTECO grammer - it does not have to be maintained separately.
  There are a few exceptions and tweaks, though.
* The contents of curly-brace escapes (`@^Uq{...}`) are rendered as ordinary
  code using a separate parser instance.
  This can be disabled with the lexer.sciteco.macrodef property.
  Unfortunately, SciTECO does not currently allow setting lexer properties (FIXME).
* Labels and comments are currently styled the same.
  This could change in the future once we introduce real comments.
* Lexers are usually implemented in C++, but I did not want to draw in C++.
  Especially not since we'd have to include parser.h and other SciTECO headers,
  that really do not want to keep C++-compatible.
  Instead, the lexer is implemented "in the container".
  @ES/SCI_SETILEXER/sciteco/ is internally translated to SCI_SETILEXER(NULL)
  and we get Scintilla notifications when styling the view becomes necessary.
  This is then centrally forwarded to the teco_lexer_style() which
  uses the ordinary teco_view_ssm() API for styling.
* Once the command line becomes a Scintilla view even on Curses,
  we can enabled syntax highlighting of the command line macro.

1 files changed, 13 insertions, 0 deletions

diff --git a/src/view.c b/src/view.c
index 7cdc987..f14c658 100644
--- a/src/view.c
+++ b/src/view.c
@@ -46,6 +46,7 @@
 #include "qreg.h"
 #include "eol.h"
 #include "memory.h"
+#include "lexer.h"
 #include "view.h"
 
 /** @memberof teco_view_t */
@@ -636,3 +637,15 @@ teco_view_get_character(teco_view_t *ctx, gsize pos, gsize len)
 	 */
 	return (gint32)g_utf8_get_char_validated(buf, -1);
 }
+
+void
+teco_view_process_notify(teco_view_t *ctx, SCNotification *notify)
+{
+#ifdef DEBUG
+	g_printf("SCINTILLA NOTIFY: code=%d\n", notify->nmhdr.code);
+#endif
+
+	if (notify->nmhdr.code == SCN_STYLENEEDED)
+		/* Lexing in the container: only used for SciTECO */
+		teco_lexer_style(ctx, notify->position);
+}