vis: add infrastructure to register custom :-commands

sam.c

@@ -109,6 +109,7 @@ static bool cmd_help(Vis*, Win*, Command*, const char *argv[], Cursor*, Filerang
 static bool cmd_map(Vis*, Win*, Command*, const char *argv[], Cursor*, Filerange*);
 static bool cmd_unmap(Vis*, Win*, Command*, const char *argv[], Cursor*, Filerange*);
 static bool cmd_langmap(Vis*, Win*, Command*, const char *argv[], Cursor*, Filerange*);
+static bool cmd_user(Vis*, Win*, Command*, const char *argv[], Cursor*, Filerange*);
 
 /* command recognized at the ':'-prompt. commands are found using a unique
  * prefix match. that is if a command should be available under an abbreviation
@@ -161,7 +162,10 @@ static const CommandDef cmds[] = {
 };
 
 static const CommandDef cmddef_select =
-	{ { "s"            }, 0,                                   NULL, cmd_select        };
+	{ { NULL           }, 0,                                   NULL, cmd_select        };
+
+static const CommandDef cmddef_user =
+	{ { NULL           }, CMD_ARGV|CMD_FORCE|CMD_ONCE,         NULL, cmd_user          };
 
 bool sam_init(Vis *vis) {
 	if (!(vis->cmds = map_new()))

vis-cmds.c

@@ -4,6 +4,50 @@
 #define VIS_OPEN "vis-open"
 #endif
 
+typedef struct {
+	CmdFunc func;
+	void *data;
+} CmdUser;
+
+bool vis_cmd_register(Vis *vis, const char *name, void *data, CmdFunc func) {
+	if (!name)
+		return false;
+	if (!vis->usercmds && !(vis->usercmds = map_new()))
+		return false;
+	CmdUser *cmd = calloc(1, sizeof *cmd);
+	if (!cmd)
+		return false;
+	cmd->func = func;
+	cmd->data = data;
+	if (!map_put(vis->cmds, name, &cmddef_user))
+		goto err;
+	if (!map_put(vis->usercmds, name, cmd)) {
+		map_delete(vis->cmds, name);
+		goto err;
+	}
+	return true;
+err:
+	free(cmd);
+	return false;
+}
+
+bool vis_cmd_unregister(Vis *vis, const char *name) {
+	if (!name)
+		return true;
+	CmdUser *cmd = map_delete(vis->usercmds, name);
+	if (!cmd)
+		return false;
+	if (!map_delete(vis->cmds, name))
+		return false;
+	free(cmd);
+	return true;
+}
+
+static bool cmd_user(Vis *vis, Win *win, Command *cmd, const char *argv[], Cursor *cur, Filerange *range) {
+	CmdUser *user = map_get(vis->usercmds, argv[0]);
+	return user && user->func(vis, win, user->data, cmd->flags == '!', argv, cur, range);
+}
+
 static void windows_arrange(Vis *vis, enum UiLayout layout) {
 	vis->ui->arrange(vis->ui, layout);
 }

vis-core.h

@@ -153,6 +153,7 @@ struct Vis {
 	bool expandtab;                      /* whether typed tabs should be converted to spaces */
 	bool autoindent;                     /* whether indentation should be copied from previous line on newline */
 	Map *cmds;                           /* ":"-commands, used for unique prefix queries */
+	Map *usercmds;                       /* user registered ":"-commands */
 	Map *options;                        /* ":set"-options */
 	Map *keymap;                         /* key translation before any bindings are matched */
 	Buffer input_queue;                  /* holds pending input keys */

vis.c

@@ -394,6 +394,7 @@ void vis_free(Vis *vis) {
 		register_release(&vis->registers[i]);
 	vis->ui->free(vis->ui);
 	map_free(vis->cmds);
+	map_free_full(vis->usercmds);
 	map_free(vis->options);
 	map_free(vis->actions);
 	map_free(vis->keymap);

vis.h

@@ -396,6 +396,14 @@ void vis_cancel(Vis*);
 
 /* execute a :-command (including an optinal range specifier) */
 bool vis_cmd(Vis*, const char *cmd);
+
+/* type of user defined function which can be registered */
+typedef bool (*CmdFunc)(Vis*, Win*, void *data, bool force,
+	const char *argv[], Cursor*, Filerange*);
+/* the function will be invoked whenever a command which matches a
+ * unique prefix of the given name is executed */
+bool vis_cmd_register(Vis*, const char *name, void *data, CmdFunc);
+bool vis_cmd_unregister(Vis*, const char *name);
 /* execute any kind (:,?,/) of prompt command */
 bool vis_prompt_cmd(Vis*, const char *cmd);