vis-lua: add win:map function for window local key mappings

Based on a patch by Josh Wainwright.

Close #306

2 files changed, 28 insertions, 8 deletions

diff --git a/README.md b/README.md
index be11bde..3c6b543 100644
--- a/README.md
+++ b/README.md
@@ -617,6 +617,7 @@ At this time there exists no API stability guarantees.
    - `cursors[1..#cursors]` array giving read access to all cursors
    - `cursor` primary cursor
    - `syntax` lexer name used for syntax highlighting or `nil`
+   - `map(mode, key, function)` map a Lua function to `key` in `mode`, local to the given window
  - `cursor`
    - `line` (1 based), `col` (1 based)
    - `to(line, col)`
diff --git a/vis-lua.c b/vis-lua.c
index 18259ef..a28efc7 100644
--- a/vis-lua.c
+++ b/vis-lua.c
@@ -376,12 +376,7 @@ static int open(lua_State *L) {
 	return 1;
 }
 
-static int map(lua_State *L) {
-	Vis *vis = obj_ref_check(L, 1, "vis");
-	if (!vis) {
-		lua_pushnil(L);
-		return 1;
-	}
+static int keymap(lua_State *L, Vis *vis, Win *win) {
 	KeyBinding *binding = NULL;
 	KeyAction *action = NULL;
 
@@ -410,8 +405,13 @@ static int map(lua_State *L) {
 
 	binding->action = action;
 
-	if (!vis_mode_map(vis, mode, true, key, binding))
-		goto err;
+	if (win) {
+		if (!vis_window_mode_map(win, mode, true, key, binding))
+			goto err;
+	} else {
+		if (!vis_mode_map(vis, mode, true, key, binding))
+			goto err;
+	}
 
 	lua_pushboolean(L, true);
 	return 1;
@@ -422,6 +422,15 @@ err:
 	return 1;
 }
 
+static int map(lua_State *L) {
+	Vis *vis = obj_ref_check(L, 1, "vis");
+	if (!vis) {
+		lua_pushboolean(L, false);
+		return 1;
+	}
+	return keymap(L, vis, NULL);
+}
+
 static int motion(lua_State *L) {
 	Vis *vis = obj_ref_check(L, 1, "vis");
 	enum VisMotion id = luaL_checkunsigned(L, 2);
@@ -682,10 +691,20 @@ static int window_cursors_iterator(lua_State *L) {
 	return 1;
 }
 
+static int window_map(lua_State *L) {
+	Win *win = obj_ref_check(L, 1, "vis.window");
+	if (!win) {
+		lua_pushboolean(L, false);
+		return 1;
+	}
+	return keymap(L, win->vis, win);
+}
+
 static const struct luaL_Reg window_funcs[] = {
 	{ "__index", window_index },
 	{ "__newindex", window_newindex },
 	{ "cursors_iterator", window_cursors_iterator },
+	{ "map", window_map },
 	{ NULL, NULL },
 };