introduced helper functions teco_qreg_table_get_string() and teco_qreg_table_get_integer()

* Simplifies the common task of querying an integer or string from a Q-Register table.
* Undefined Q-Regs are reported as TECO_ERROR_QREGUNDEF, so you can theoretically
  handle this case. In practice however, it requires less boilerplating to
  just call teco_qreg_table_find() manually.
* It also doesn't make sense to use these functions when getting and setting
  a register at the same time as you will want to avoid repeated lookups.

11 files changed, 67 insertions, 78 deletions

diff --git a/src/cmdline.c b/src/cmdline.c
index 572b159..d2d9d04 100644
--- a/src/cmdline.c
+++ b/src/cmdline.c
@@ -173,11 +173,9 @@ teco_cmdline_insert(const gchar *data, gsize len, GError **error)
 				 */
 				g_clear_error(&tmp_error);
 
-				teco_qreg_t *cmdline_reg = teco_qreg_table_find(&teco_qreg_table_globals, "\e", 1);
 				g_auto(teco_string_t) new_cmdline = {NULL, 0};
-
-				if (!cmdline_reg->vtable->get_string(cmdline_reg, &new_cmdline.data, &new_cmdline.len,
-				                                     NULL, &tmp_error)) {
+				if (!teco_qreg_table_get_string(&teco_qreg_table_globals, "\e",
+				                                &new_cmdline.data, &new_cmdline.len, &tmp_error)) {
 					teco_error_add_frame_toplevel();
 					teco_error_display_short(tmp_error);
 					g_propagate_error(error, g_steal_pointer(&tmp_error));
diff --git a/src/core-commands.c b/src/core-commands.c
index 8f84224..d01cbb9 100644
--- a/src/core-commands.c
+++ b/src/core-commands.c
@@ -461,10 +461,8 @@ teco_state_start_break(teco_machine_main_t *ctx, GError **error)
 		return;
 	}
 
-	teco_qreg_t *reg = teco_qreg_table_find(&teco_qreg_table_globals, "_", 1);
-	g_assert(reg != NULL);
 	teco_int_t v;
-	if (!reg->vtable->get_integer(reg, &v, error))
+	if (!teco_qreg_table_get_integer(&teco_qreg_table_globals, "_", &v, error))
 		return;
 
 	teco_bool_t rc;
@@ -1134,10 +1132,9 @@ teco_state_changedir_done(teco_machine_main_t *ctx, teco_string_t str, GError **
 
 	g_autofree gchar *dir = teco_file_expand_path(str.data);
 	if (!*dir) {
-		teco_qreg_t *qreg = teco_qreg_table_find(&teco_qreg_table_globals, "$HOME", 5);
-		g_assert(qreg != NULL);
 		teco_string_t home;
-		if (!qreg->vtable->get_string(qreg, &home.data, &home.len, NULL, error))
+		if (!teco_qreg_table_get_string(&teco_qreg_table_globals, "$HOME",
+		                                &home.data, &home.len, error))
 			return NULL;
 
 		/*
diff --git a/src/error.h b/src/error.h
index a848116..1306feb 100644
--- a/src/error.h
+++ b/src/error.h
@@ -50,6 +50,7 @@ typedef enum {
 	TECO_ERROR_SUBPATTERN,
 	TECO_ERROR_INVALIDBUF,
 	TECO_ERROR_INVALIDQREG,
+	TECO_ERROR_QREGUNDEF,
 	TECO_ERROR_QREGOPUNSUPPORTED,
 	TECO_ERROR_QREGCONTAINSNULL,
 	TECO_ERROR_EDITINGLOCALQREG,
diff --git a/src/file-utils.c b/src/file-utils.c
index 8555271..4bf5e6a 100644
--- a/src/file-utils.c
+++ b/src/file-utils.c
@@ -348,18 +348,13 @@ teco_file_expand_path(const gchar *path)
 	 * but this ensures that a proper path is constructed even if
 	 * it does (e.g. $HOME is changed later on).
 	 *
-	 * FIXME: In the future, it might be possible to remove the entire register.
-	 */
-	teco_qreg_t *qreg = teco_qreg_table_find(&teco_qreg_table_globals, "$HOME", 5);
-	g_assert(qreg != NULL);
-
-	/*
 	 * Getting the string should not possible to fail.
 	 * The $HOME register should not contain any null-bytes on startup,
 	 * but it may have been changed later on.
 	 */
 	g_auto(teco_string_t) home = {NULL, 0};
-	if (!qreg->vtable->get_string(qreg, &home.data, &home.len, NULL, NULL) ||
+	if (!teco_qreg_table_get_string(&teco_qreg_table_globals, "$HOME",
+	                                &home.data, &home.len, NULL) ||
 	    teco_string_contains(home, '\0'))
 		return g_strdup(path);
 	g_assert(home.data != NULL);
diff --git a/src/help.c b/src/help.c
index b7b5fd0..db8a974 100644
--- a/src/help.c
+++ b/src/help.c
@@ -92,10 +92,9 @@ teco_help_init(GError **error)
 	teco_help_chunk = g_string_chunk_new(32);
 	rb3_reset_tree(&teco_help_tree);
 
-	teco_qreg_t *lib_reg = teco_qreg_table_find(&teco_qreg_table_globals, "$SCITECOPATH", 12);
-	g_assert(lib_reg != NULL);
 	g_auto(teco_string_t) lib_path = {NULL, 0};
-	if (!lib_reg->vtable->get_string(lib_reg, &lib_path.data, &lib_path.len, NULL, error))
+	if (!teco_qreg_table_get_string(&teco_qreg_table_globals, "$SCITECOPATH",
+	                                &lib_path.data, &lib_path.len, error))
 		return FALSE;
 	/*
 	 * FIXME: lib_path may contain null-bytes.
diff --git a/src/interface-curses/interface.c b/src/interface-curses/interface.c
index db996f5..fbac2cb 100644
--- a/src/interface-curses/interface.c
+++ b/src/interface-curses/interface.c
@@ -1527,17 +1527,12 @@ teco_interface_set_clipboard(const gchar *name, const gchar *str, gsize str_len,
 
 	static const gchar reg_name[] = "$SCITECO_CLIPBOARD_SET";
 
-	teco_qreg_t *reg = teco_qreg_table_find(&teco_qreg_table_globals, reg_name, strlen(reg_name));
-	if (!reg) {
-		/* Q-Register could have been removed in the meantime */
-		g_set_error(error, TECO_ERROR, TECO_ERROR_FAILED,
-		            "Cannot set clipboard. %s is undefined.", reg_name);
-		return FALSE;
-	}
-
 	g_auto(teco_string_t) command = {NULL, 0};
-	if (!reg->vtable->get_string(reg, &command.data, &command.len, NULL, error))
+	if (!teco_qreg_table_get_string(&teco_qreg_table_globals, reg_name,
+	                                &command.data, &command.len, error)) {
+		g_prefix_error(error, "Cannot set clipboard: ");
 		return FALSE;
+	}
 	if (teco_string_contains(command, '\0')) {
 		teco_error_qregcontainsnull_set(error, reg_name, strlen(reg_name), FALSE);
 		return FALSE;
@@ -1588,17 +1583,12 @@ teco_interface_get_clipboard(const gchar *name, gchar **str, gsize *len, GError
 
 	static const gchar reg_name[] = "$SCITECO_CLIPBOARD_GET";
 
-	teco_qreg_t *reg = teco_qreg_table_find(&teco_qreg_table_globals, reg_name, strlen(reg_name));
-	if (!reg) {
-		/* Q-Register could have been removed in the meantime */
-		g_set_error(error, TECO_ERROR, TECO_ERROR_FAILED,
-		            "Cannot get clipboard. %s is undefined.", reg_name);
-		return FALSE;
-	}
-
 	g_auto(teco_string_t) command = {NULL, 0};
-	if (!reg->vtable->get_string(reg, &command.data, &command.len, NULL, error))
+	if (!teco_qreg_table_get_string(&teco_qreg_table_globals, reg_name,
+	                                &command.data, &command.len, error)) {
+		g_prefix_error(error, "Cannot get clipboard: ");
 		return FALSE;
+	}
 	if (teco_string_contains(command, '\0')) {
 		teco_error_qregcontainsnull_set(error, reg_name, strlen(reg_name), FALSE);
 		return FALSE;
diff --git a/src/interface-gtk/interface.c b/src/interface-gtk/interface.c
index 1f6259f..b2d4788 100644
--- a/src/interface-gtk/interface.c
+++ b/src/interface-gtk/interface.c
@@ -1210,11 +1210,9 @@ teco_interface_handle_scroll(GdkEventScroll *event, GError **error)
 gboolean
 teco_interface_event_loop(GError **error)
 {
-	teco_qreg_t *scitecoconfig_reg = teco_qreg_table_find(&teco_qreg_table_globals, "$SCITECOCONFIG", 14);
-	g_assert(scitecoconfig_reg != NULL);
 	g_auto(teco_string_t) scitecoconfig = {NULL, 0};
-	if (!scitecoconfig_reg->vtable->get_string(scitecoconfig_reg,
-	                                           &scitecoconfig.data, &scitecoconfig.len, NULL, error))
+	if (!teco_qreg_table_get_string(&teco_qreg_table_globals, "$SCITECOCONFIG",
+	                                &scitecoconfig.data, &scitecoconfig.len, error))
 		return FALSE;
 	if (teco_string_contains(scitecoconfig, '\0')) {
 		g_set_error_literal(error, TECO_ERROR, TECO_ERROR_FAILED,
diff --git a/src/lsp.c b/src/lsp.c
index 2c1f89b..ff7ddc7 100644
--- a/src/lsp.c
+++ b/src/lsp.c
@@ -444,16 +444,9 @@ teco_lsp_launch(GError **error)
 	                                 G_SPAWN_STDERR_TO_DEV_NULL;
 
 	static const gchar lsp_reg_name[] = "$SCITECO_LSP";
-	teco_qreg_t *reg = teco_qreg_table_find(&teco_qreg_table_globals,
-	                                        lsp_reg_name, strlen(lsp_reg_name));
-	if (!reg) {
-		g_set_error(error, TECO_ERROR, TECO_ERROR_FAILED,
-		            "Q-Register %s is undefined.", lsp_reg_name);
-		return FALSE;
-	}
-
 	g_auto(teco_string_t) command = {NULL, 0};
-	if (!reg->vtable->get_string(reg, &command.data, &command.len, NULL, error))
+	if (!teco_qreg_table_get_string(&teco_qreg_table_globals, lsp_reg_name,
+	                                &command.data, &command.len, error))
 		return FALSE;
 	if (teco_string_contains(command, '\0')) {
 		teco_error_qregcontainsnull_set(error, lsp_reg_name, strlen(lsp_reg_name), FALSE);
@@ -497,8 +490,8 @@ teco_lsp_launch(GError **error)
 	g_auto(teco_string_t) root = {NULL, 0};
 
 	static const gchar root_reg_name[] = "$SCITECO_LSP_ROOT";
-	reg = teco_qreg_table_find(&teco_qreg_table_globals,
-	                           root_reg_name, strlen(root_reg_name));
+	teco_qreg_t *reg = teco_qreg_table_find(&teco_qreg_table_globals,
+	                                        root_reg_name, strlen(root_reg_name));
 	if (reg) {
 		if (!reg->vtable->get_string(reg, &root.data, &root.len, NULL, error))
 			return FALSE;
diff --git a/src/qreg.h b/src/qreg.h
index ca35e78..1eb2cf8 100644
--- a/src/qreg.h
+++ b/src/qreg.h
@@ -16,6 +16,8 @@
  */
 #pragma once
 
+#include <string.h>
+
 #include <glib.h>
 
 //#include <rb3ptr.h>
@@ -24,6 +26,7 @@
 #include "view.h"
 #include "doc.h"
 #include "undo.h"
+#include "error.h"
 #include "string-utils.h"
 #include "rb3str.h"
 
@@ -212,6 +215,36 @@ teco_qreg_table_find(teco_qreg_table_t *table, const gchar *name, gsize len)
 	return (teco_qreg_t *)teco_rb3str_find(&table->tree, TRUE, name, len);
 }
 
+/** @memberof teco_qreg_table_t */
+static inline gboolean
+teco_qreg_table_get_string(teco_qreg_table_t *table, const gchar *name,
+                           gchar **str, gsize *len, GError **error)
+{
+	teco_qreg_t *reg = teco_qreg_table_find(table, name, strlen(name));
+	if (!reg) {
+		g_set_error(error, TECO_ERROR, TECO_ERROR_QREGUNDEF,
+		            "Q-Register \"%s\" is undefined.", name);
+		return FALSE;
+	}
+
+	return reg->vtable->get_string(reg, str, len, NULL, error);
+}
+
+/** @memberof teco_qreg_table_t */
+static inline gboolean
+teco_qreg_table_get_integer(teco_qreg_table_t *table, const gchar *name,
+                            teco_int_t *ret, GError **error)
+{
+	teco_qreg_t *reg = teco_qreg_table_find(table, name, strlen(name));
+	if (!reg) {
+		g_set_error(error, TECO_ERROR, TECO_ERROR_QREGUNDEF,
+		            "Q-Register \"%s\" is undefined.", name);
+		return FALSE;
+	}
+
+	return reg->vtable->get_integer(reg, ret, error);
+}
+
 teco_qreg_t *teco_qreg_table_edit_name(teco_qreg_table_t *table, const gchar *name,
                                        gsize len, GError **error);
 
diff --git a/src/search.c b/src/search.c
index 357a0c0..2b2a696 100644
--- a/src/search.c
+++ b/src/search.c
@@ -928,10 +928,9 @@ teco_state_search_process(teco_machine_main_t *ctx, teco_string_t str, gsize new
 {
 	gint cflags = REG_ADVANCED;
 
-	teco_qreg_t *reg = teco_qreg_table_find(ctx->qreg_table_locals, "\x18", 1); /* ^X */
-	g_assert(reg != NULL);
 	teco_bool_t search_mode;
-	if (!reg->vtable->get_integer(reg, &search_mode, error))
+	if (!teco_qreg_table_get_integer(ctx->qreg_table_locals, "\x18", /* ^X */
+	                                 &search_mode, error))
 		return FALSE;
 	if (teco_is_failure(search_mode))
 		cflags |= REG_ICASE;
@@ -1344,12 +1343,9 @@ teco_state_search_kill_done(teco_machine_main_t *ctx, teco_string_t str, GError
 	if (ctx->flags.mode > TECO_MODE_NORMAL)
 		return &teco_state_start;
 
-	teco_qreg_t *search_reg = teco_qreg_table_find(&teco_qreg_table_globals, "_", 1);
-	g_assert(search_reg != NULL);
-
 	teco_int_t search_state;
 	if (!teco_state_search_done(ctx, str, error) ||
-	    !search_reg->vtable->get_integer(search_reg, &search_state, error))
+	    !teco_qreg_table_get_integer(&teco_qreg_table_globals, "_", &search_state, error))
 		return NULL;
 
 	if (teco_is_failure(search_state))
@@ -1433,12 +1429,9 @@ teco_state_search_delete_done(teco_machine_main_t *ctx, teco_string_t str, GErro
 	if (ctx->flags.mode > TECO_MODE_NORMAL)
 		return &teco_state_start;
 
-	teco_qreg_t *search_reg = teco_qreg_table_find(&teco_qreg_table_globals, "_", 1);
-	g_assert(search_reg != NULL);
-
 	teco_int_t search_state;
 	if (!teco_state_search_done(ctx, str, error) ||
-	    !search_reg->vtable->get_integer(search_reg, &search_state, error))
+	    !teco_qreg_table_get_integer(&teco_qreg_table_globals, "_", &search_state, error))
 		return NULL;
 
 	if (teco_is_success(search_state)) {
@@ -1519,12 +1512,9 @@ teco_state_replace_done(teco_machine_main_t *ctx, teco_string_t str, GError **er
 	if (ctx->flags.mode > TECO_MODE_NORMAL)
 		return &teco_state_replace_ignore;
 
-	teco_qreg_t *search_reg = teco_qreg_table_find(&teco_qreg_table_globals, "_", 1);
-	g_assert(search_reg != NULL);
-
 	teco_int_t search_state;
 	if (!teco_state_search_delete_done(ctx, str, error) ||
-	    !search_reg->vtable->get_integer(search_reg, &search_state, error))
+	    !teco_qreg_table_get_integer(&teco_qreg_table_globals, "_", &search_state, error))
 		return NULL;
 
 	return teco_is_success(search_state) ? &teco_state_replace_insert
@@ -1627,12 +1617,9 @@ teco_state_replace_default_done(teco_machine_main_t *ctx, teco_string_t str, GEr
 	if (ctx->flags.mode > TECO_MODE_NORMAL)
 		return &teco_state_replace_default_ignore;
 
-	teco_qreg_t *search_reg = teco_qreg_table_find(&teco_qreg_table_globals, "_", 1);
-	g_assert(search_reg != NULL);
-
 	teco_int_t search_state;
 	if (!teco_state_search_delete_done(ctx, str, error) ||
-	    !search_reg->vtable->get_integer(search_reg, &search_state, error))
+	    !teco_qreg_table_get_integer(&teco_qreg_table_globals, "_", &search_state, error))
 		return NULL;
 
 	return teco_is_success(search_state) ? &teco_state_replace_default_insert
diff --git a/src/spawn.c b/src/spawn.c
index 6289830..644bf31 100644
--- a/src/spawn.c
+++ b/src/spawn.c
@@ -125,10 +125,9 @@ teco_parse_shell_command_line(const gchar *cmdline, GError **error)
 
 #ifdef G_OS_WIN32
 	if (!(teco_ed & TECO_ED_SHELLEMU)) {
-		teco_qreg_t *reg = teco_qreg_table_find(&teco_qreg_table_globals, "$COMSPEC", 8);
-		g_assert(reg != NULL);
 		teco_string_t comspec;
-		if (!reg->vtable->get_string(reg, &comspec.data, &comspec.len, NULL, error))
+		if (!teco_qreg_table_get_string(&teco_qreg_table_globals, "$COMSPEC",
+		                                &comspec.data, &comspec.len, error))
 			return NULL;
 		if (teco_string_contains(comspec, '\0')) {
 			teco_string_clear(&comspec);
@@ -145,10 +144,9 @@ teco_parse_shell_command_line(const gchar *cmdline, GError **error)
 	}
 #elif defined(G_OS_UNIX)
 	if (!(teco_ed & TECO_ED_SHELLEMU)) {
-		teco_qreg_t *reg = teco_qreg_table_find(&teco_qreg_table_globals, "$SHELL", 6);
-		g_assert(reg != NULL);
 		teco_string_t shell;
-		if (!reg->vtable->get_string(reg, &shell.data, &shell.len, NULL, error))
+		if (!teco_qreg_table_get_string(&teco_qreg_table_globals, "$SHELL",
+		                                &shell.data, &shell.len, error))
 			return NULL;
 		if (teco_string_contains(shell, '\0')) {
 			teco_string_clear(&shell);