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, 15 insertions, 5 deletions

diff --git a/src/core-commands.c b/src/core-commands.c
index 2f473ce..52b577d 100644
--- a/src/core-commands.c
+++ b/src/core-commands.c
@@ -31,6 +31,7 @@
 #include "expressions.h"
 #include "ring.h"
 #include "parser.h"
+#include "lexer.h"
 #include "symbols.h"
 #include "search.h"
 #include "spawn.h"
@@ -1293,7 +1294,8 @@ teco_state_start_input(teco_machine_main_t *ctx, gunichar chr, GError **error)
 TECO_DEFINE_STATE_CASEINSENSITIVE(teco_state_start,
 	.end_of_macro_cb = NULL, /* Allowed at the end of a macro! */
 	.is_start = TRUE,
-	.keymacro_mask = TECO_KEYMACRO_MASK_START | TECO_KEYMACRO_MASK_CASEINSENSITIVE
+	.keymacro_mask = TECO_KEYMACRO_MASK_START | TECO_KEYMACRO_MASK_CASEINSENSITIVE,
+	.style = SCE_SCITECO_COMMAND
 );
 
 /*$ F<
@@ -1450,7 +1452,9 @@ teco_state_fcommand_input(teco_machine_main_t *ctx, gunichar chr, GError **error
 	                                          teco_ascii_toupper(chr), error);
 }
 
-TECO_DEFINE_STATE_CASEINSENSITIVE(teco_state_fcommand);
+TECO_DEFINE_STATE_CASEINSENSITIVE(teco_state_fcommand,
+	.style = SCE_SCITECO_COMMAND
+);
 
 static void
 teco_undo_change_dir_action(gchar **dir, gboolean run)
@@ -1657,7 +1661,9 @@ teco_state_condcommand_input(teco_machine_main_t *ctx, gunichar chr, GError **er
 	return &teco_state_start;
 }
 
-TECO_DEFINE_STATE_CASEINSENSITIVE(teco_state_condcommand);
+TECO_DEFINE_STATE_CASEINSENSITIVE(teco_state_condcommand,
+	.style = SCE_SCITECO_OPERATOR
+);
 
 /*$ ^_ negate
  * n^_ -> ~n -- Binary negation
@@ -2055,7 +2061,9 @@ teco_state_control_input(teco_machine_main_t *ctx, gunichar chr, GError **error)
 	                                          teco_ascii_toupper(chr), error);
 }
 
-TECO_DEFINE_STATE_CASEINSENSITIVE(teco_state_control);
+TECO_DEFINE_STATE_CASEINSENSITIVE(teco_state_control,
+	.style = SCE_SCITECO_COMMAND
+);
 
 static teco_state_t *
 teco_state_ascii_input(teco_machine_main_t *ctx, gunichar chr, GError **error)
@@ -2956,7 +2964,9 @@ teco_state_ecommand_input(teco_machine_main_t *ctx, gunichar chr, GError **error
 	                                          teco_ascii_toupper(chr), error);
 }
 
-TECO_DEFINE_STATE_CASEINSENSITIVE(teco_state_ecommand);
+TECO_DEFINE_STATE_CASEINSENSITIVE(teco_state_ecommand,
+	.style = SCE_SCITECO_COMMAND
+);
 
 gboolean
 teco_state_insert_initial(teco_machine_main_t *ctx, GError **error)