throw an error immediately after nEB if n != 0

* When typing nEBfilename$ (n != 0) you would find out that the construct is invalid
  only after typing out the entire command.
  We now throw an error immediately, ie. only Escape or string termination will be expected
  in interactive mode.
* In batch mode, nothing should have changed.

2 files changed, 26 insertions, 18 deletions

diff --git a/src/parser.h b/src/parser.h
index 095f523..2308925 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -494,6 +494,9 @@ struct teco_machine_main_t {
 		 * This is tracked even in parse-only mode.
 		 */
 		guint modifier_at : 1;
+
+		/** whether <EB> command accepts a filename */
+		guint allow_filename : 1;
 	} flags;
 
 	/** The nesting level of braces */
diff --git a/src/ring.c b/src/ring.c
index d389e52..0dbe911 100644
--- a/src/ring.c
+++ b/src/ring.c
@@ -405,13 +405,6 @@ teco_ring_cleanup(void)
  * Command states
  */
 
-/*
- * FIXME: Should be part of the teco_machine_main_t?
- * Unfortunately, we cannot just merge initial() with done(),
- * since we want to react immediately to xEB without waiting for $.
- */
-static gboolean allow_filename = FALSE;
-
 static gboolean
 teco_state_edit_file_initial(teco_machine_main_t *ctx, GError **error)
 {
@@ -422,7 +415,7 @@ teco_state_edit_file_initial(teco_machine_main_t *ctx, GError **error)
 	if (!teco_expressions_pop_num_calc(&id, -1, error))
 		return FALSE;
 
-	allow_filename = TRUE;
+	ctx->flags.allow_filename = TRUE;
 
 	if (id == 0) {
 		for (teco_buffer_t *cur = teco_ring_first(); cur; cur = teco_buffer_next(cur)) {
@@ -433,7 +426,7 @@ teco_state_edit_file_initial(teco_machine_main_t *ctx, GError **error)
 
 		teco_interface_popup_show(0);
 	} else if (id > 0) {
-		allow_filename = FALSE;
+		ctx->flags.allow_filename = FALSE;
 		if (!teco_current_doc_undo_edit(error) ||
 		    !teco_ring_edit(id, error))
 			return FALSE;
@@ -442,20 +435,31 @@ teco_state_edit_file_initial(teco_machine_main_t *ctx, GError **error)
 	return TRUE;
 }
 
+gboolean
+teco_state_edit_file_process(teco_machine_main_t *ctx, const teco_string_t *str,
+                             gsize new_chars, GError **error)
+{
+	g_assert(new_chars > 0);
+
+	if (!ctx->flags.allow_filename) {
+		g_set_error_literal(error, TECO_ERROR, TECO_ERROR_FAILED,
+		                    "If a buffer is selected by id, the <EB> "
+		                    "string argument must be empty");
+		return FALSE;
+	}
+
+	return TRUE;
+}
+
 static teco_state_t *
 teco_state_edit_file_done(teco_machine_main_t *ctx, const teco_string_t *str, GError **error)
 {
 	if (ctx->flags.mode > TECO_MODE_NORMAL)
 		return &teco_state_start;
 
-	if (!allow_filename) {
-		if (str->len > 0) {
-			g_set_error_literal(error, TECO_ERROR, TECO_ERROR_FAILED,
-			                    "If a buffer is selected by id, the <EB> "
-			                    "string argument must be empty");
-			return NULL;
-		}
-
+	if (!ctx->flags.allow_filename) {
+		/* process_cb() already throws error if str->len > 0 */
+		g_assert(str->len == 0);
 		return &teco_state_start;
 	}
 
@@ -536,7 +540,8 @@ teco_state_edit_file_done(teco_machine_main_t *ctx, const teco_string_t *str, GE
  * ecetera.
  */
 TECO_DEFINE_STATE_EXPECTGLOB(teco_state_edit_file,
-	.initial_cb = (teco_state_initial_cb_t)teco_state_edit_file_initial
+	.initial_cb = (teco_state_initial_cb_t)teco_state_edit_file_initial,
+	.expectstring.process_cb = teco_state_edit_file_process
 );
 
 static teco_state_t *