ipc: allow sending commands with named arguments

This has been part of the libmpv for a while, so the implementation in
the IPC code is quite simple: just pass the mpv_node representing the
value of the "command" field without further checks to
mpv_command_node().

The only problem are the IPC-specific commands, which essentially have
their own dispatch mechanism. They expect an array. I'm not going to
rewrite the dispatch mechanism, so these still work only with an array.
I decided make the other case explicit with cmd==NULL. (I could also
have set cmd=="", which would have avoided changing each if condition
since "" matches no existing command, but that felt dirty.)

1 files changed, 11 insertions, 0 deletions

diff --git a/DOCS/man/ipc.rst b/DOCS/man/ipc.rst
index 40e0730089..fdf5daf9b6 100644
--- a/DOCS/man/ipc.rst
+++ b/DOCS/man/ipc.rst
@@ -202,6 +202,17 @@ commands that finished execution immediately.
 Cancellation of asynchronous commands is available in the libmpv API, but has
 not yet been implemented in the IPC protocol.
 
+Commands with named arguments
+-----------------------------
+
+If the ``command`` field is a JSON object, named arguments are expected. This
+is described in the C API ``mpv_command_node()`` documentation (the
+``MPV_FORMAT_NODE_MAP`` case). In some cases, this may make commands more
+readable, while some obscure commands basically require using named arguments.
+
+Currently, only "proper" commands (as listed by `List of Input Commands`_)
+support named arguments.
+
 Commands
 --------