The Task.Extra module contains:
message : msg -> Cmd msg
message x =
Task.perform identity (Task.succeed x)
Which is a useful way of creating a Cmd from a Msg.
The Update modules provide functions for lifting nested update functions into a
parent update function, following the so-called 'nested TEA' pattern.
The Update2 module is for update functions that return a new Model and a Cmd.
The Update3 module is for update functions that also return an additional 'out message'.
The Update3Alt module is for update functions that also return an additional
'out message', but as the second item in the return tuple, instead of the last.
These update functions help with composing update functions together.