vis: introduce special keys which allow mappings to editor actions

Key bindings in vis are always recursive, hence mapping ~
to ~l will cause an infinite loop.

Instead vis supports special editor "keys" which map to
internal editor functions.

As an example one can thus map ~ to <vis-operator-case-swap>l
or even <vis-operator-case-swap><cursor-char-next>

Furthermore this makes it possible to completely unmap core
editor features such as operators, the corresponding funtionality
is still available via its corresponding special key.

3 files changed, 44 insertions, 1 deletions

diff --git a/editor.c b/editor.c
index c07eed7..4484b0a 100644
--- a/editor.c
+++ b/editor.c
@@ -252,6 +252,14 @@ bool editor_mode_unmap(Mode *mode, const char *name) {
 	return map_delete(mode->bindings, name);
 }
 
+bool editor_action_register(Editor *ed, KeyAction *action) {
+	if (!ed->actions)
+		ed->actions = map_new();
+	if (!ed->actions)
+		return false;
+	return map_put(ed->actions, action->name, action);
+}
+
 static void window_free(Win *win) {
 	if (!win)
 		return;
@@ -430,6 +438,7 @@ void editor_free(Editor *ed) {
 	ed->ui->free(ed->ui);
 	map_free(ed->cmds);
 	map_free(ed->options);
+	map_free(ed->actions);
 	buffer_release(&ed->buffer_repeat);
 	free(ed);
 }
diff --git a/editor.h b/editor.h
index 87d9aeb..e7b5f0a 100644
--- a/editor.h
+++ b/editor.h
@@ -253,6 +253,7 @@ struct Editor {
 	volatile sig_atomic_t cancel_filter; /* abort external command */
 	volatile sig_atomic_t sigbus;
 	sigjmp_buf sigbus_jmpbuf;
+	Map *actions;          /* built in special editor keys / commands */
 };
 
 Editor *editor_new(Ui*);
@@ -266,6 +267,8 @@ bool editor_mode_bindings(Mode*, KeyBinding**);
 bool editor_mode_map(Mode*, const char *name, KeyBinding*);
 bool editor_mode_unmap(Mode*, const char *name);
 
+bool editor_action_register(Editor*, KeyAction*);
+
 /* these function operate on the currently focused window but make sure
  * that all windows which show the affected region are redrawn too. */
 void editor_insert_key(Editor*, const char *data, size_t len);
diff --git a/vis.c b/vis.c
index 5057ab9..c4fbc29 100644
--- a/vis.c
+++ b/vis.c
@@ -2600,6 +2600,18 @@ static const char *keynext(const char *keys) {
 	/* first try to parse a special key of the form <Key> */
 	if (*keys == '<' && (next = termkey_strpkey(termkey, keys+1, &key, TERMKEY_FORMAT_VIM)) && *next == '>')
 		return next+1;
+	if (*keys == '<') {
+		const char *start = keys + 1, *end = start;
+		while (*end && *end != '>')
+			end++;
+		if (end > start && end - start - 1 < 64 && *end == '>') {
+			char key[64];
+			memcpy(key, start, end - start);
+			key[end - start] = '\0';
+			if (map_get(vis->actions, key))
+				return end + 1;
+		}
+	}
 	while (!ISUTF8(*keys))
 		keys++;
 	return termkey_strpkey(termkey, keys, &key, TERMKEY_FORMAT_VIM);
@@ -2655,7 +2667,20 @@ static const char *keypress(const char *input) {
 		} else if (prefix) { /* incomplete key binding? */
 			cur = end;
 		} else { /* no keybinding */
-			if (vis->mode->input)
+			KeyAction *action = NULL;
+			if (start[0] == '<' && end[-1] == '>') {
+				/* test for special editor key command */
+				char tmp = end[-1];
+				end[-1] = '\0';
+				action = map_get(vis->actions, start+1);
+				end[-1] = tmp;
+				if (action) {
+					end = (char*)action->func(end, &action->arg);
+					if (!end)
+						break;
+				}
+			}
+			if (!action && vis->mode->input)
 				vis->mode->input(start, end - start);
 			start = cur = end;
 		}
@@ -2780,6 +2805,12 @@ int main(int argc, char *argv[]) {
 	if (!editor_syntax_load(vis, syntaxes))
 		die("Could not load syntax highlighting definitions\n");
 
+	for (int i = 0; i < LENGTH(vis_action); i++) {
+		KeyAction *action = &vis_action[i];
+		if (!editor_action_register(vis, action))
+			die("Could not register action: %s\n", action->name);
+	}
+
 	char *cmd = NULL;
 	bool end_of_options = false;
 	for (int i = 1; i < argc; i++) {