vis-lua: expose currently active key bindings through API

Close #563

3 files changed, 40 insertions, 1 deletions

diff --git a/vis-core.h b/vis-core.h
index c9a1ffc..1ffb980 100644
--- a/vis-core.h
+++ b/vis-core.h
@@ -262,6 +262,7 @@ void vis_do(Vis *vis);
 void action_reset(Action*);
 size_t vis_text_insert_nl(Vis*, Text*, size_t pos);
 
+Mode *mode_get(Vis*, enum VisMode);
 void mode_set(Vis *vis, Mode *new_mode);
 Macro *macro_get(Vis *vis, enum VisRegister);
 
diff --git a/vis-lua.c b/vis-lua.c
index 58403d4..ba74d27 100644
--- a/vis-lua.c
+++ b/vis-lua.c
@@ -906,6 +906,43 @@ static int map(lua_State *L) {
 }
 
 /***
+ * Get all currently active mappings of a mode.
+ *
+ * @function mappings
+ * @tparam int mode the mode to query
+ * @treturn table the active mappings and their associated help texts
+ * @usage
+ * local bindings = vis:mappings(vis.modes.NORMAL)
+ * for key, help in pairs(bindings) do
+ * 	-- do something
+ * end
+ * @see Vis:map
+ */
+static bool binding_collect(const char *key, void *value, void *ctx) {
+	lua_State *L = ctx;
+	KeyBinding *binding = value;
+	lua_getfield(L, -1, key);
+	bool new = lua_isnil(L, -1);
+	lua_pop(L, 1);
+	if (new) {
+		lua_pushstring(L, binding->alias ? binding->alias : binding->action->help);
+		lua_setfield(L, -2, key);
+	}
+	return true;
+}
+
+static int mappings(lua_State *L) {
+	Vis *vis = obj_ref_check(L, 1, "vis");
+	lua_newtable(L);
+	for (Mode *mode = mode_get(vis, luaL_checkint(L, 2)); mode; mode = mode->parent) {
+		if (!mode->bindings)
+			continue;
+		map_iterate(mode->bindings, binding_collect, vis->lua);
+	}
+	return 1;
+}
+
+/***
  * Execute a motion.
  *
  * @function motion
@@ -1384,6 +1421,7 @@ static const struct luaL_Reg vis_lua[] = {
 	{ "info", info },
 	{ "message", message },
 	{ "map", map },
+	{ "mappings", mappings },
 	{ "operator", operator },
 	{ "operator_register", operator_register },
 	{ "motion", motion },
diff --git a/vis-modes.c b/vis-modes.c
index 4dbe0c7..0609022 100644
--- a/vis-modes.c
+++ b/vis-modes.c
@@ -70,7 +70,7 @@ void vis_binding_free(Vis *vis, KeyBinding *binding) {
 	}
 }
 
-static Mode *mode_get(Vis *vis, enum VisMode mode) {
+Mode *mode_get(Vis *vis, enum VisMode mode) {
 	if (mode < LENGTH(vis_modes))
 		return &vis_modes[mode];
 	return NULL;