support <:^A> to force raw ANSI output

* ^A uses the default code page without colon, just like ^U/EU.
  This is usually UTF8, unless you run with --8bit.
  It would make just as little sense to inherit the codepage from the
  current document.
* Ensures that code like `:^A^E<0xFF>^A` really outputs byte 0xFF.
* DEC TECO doesn't have the colon modifier, but it has a colon modifier
  for ^T to enforce raw output.
  In SciTECO, the ^T vs. :^T distinction will also be between default codepage
  and ANSI. It makes sense because ^T should treat its numeric arguments like <I>
  for consistency.

2 files changed, 16 insertions, 4 deletions

diff --git a/src/core-commands.c b/src/core-commands.c
index e67aa2f..2669748 100644
--- a/src/core-commands.c
+++ b/src/core-commands.c
@@ -1549,7 +1549,7 @@ teco_state_control_input(teco_machine_main_t *ctx, gunichar chr, GError **error)
 		['[']  = {&teco_state_escape},
 		['C']  = {&teco_state_ctlc},
 		['A']  = {&teco_state_print_string,
-		          .modifier_at = TRUE},
+		          .modifier_at = TRUE, .modifier_colon = 1},
 
 		/*
 		 * Additional numeric operations
diff --git a/src/stdio-commands.c b/src/stdio-commands.c
index 30f3808..0c8d20c 100644
--- a/src/stdio-commands.c
+++ b/src/stdio-commands.c
@@ -218,8 +218,13 @@ teco_state_print_string_initial(teco_machine_main_t *ctx, GError **error)
 		teco_undo_gunichar(ctx->expectstring.machine.escape_char);
 	ctx->expectstring.machine.escape_char = TECO_CTL_KEY('A');
 
-	/* chain to the default initial_cb */
-	return teco_state_expectstring_initial(ctx, error);
+	if (ctx->flags.mode > TECO_MODE_NORMAL)
+		return TRUE;
+
+	teco_machine_stringbuilding_set_codepage(&ctx->expectstring.machine,
+	                                         teco_machine_main_eval_colon(ctx)
+	                                         ? SC_CHARSET_ANSI : teco_default_codepage());
+	return TRUE;
 }
 
 static teco_state_t *
@@ -229,9 +234,10 @@ teco_state_print_string_done(teco_machine_main_t *ctx, const teco_string_t *str,
 	return &teco_state_start;
 }
 
-/*$ "^A" print "print string"
+/*$ "^A" ":^A" print "print string"
  * ^A<string>^A -- Print string as message
  * @^A/string/
+ * :^A<string>^A
  *
  * Print <string> as a message, i.e. in the message line
  * in interactive mode and if possible on the terminal (stdout) as well.
@@ -245,6 +251,12 @@ teco_state_print_string_done(teco_machine_main_t *ctx, const teco_string_t *str,
  * by \fB@\fP-modifying the command.
  *
  * String-building characters are enabled for this command.
+ * \fB^A\fP outputs strings in the default codepage,
+ * but when colon modified raw ANSI encoding is enforced.
+ */
+/*
+ * NOTE: Codepage is among other things important for
+ * ^EUq, ^E<...> and case folding.
  */
 TECO_DEFINE_STATE_EXPECTSTRING(teco_state_print_string,
 	.initial_cb = (teco_state_initial_cb_t)teco_state_print_string_initial