Command support

[caelunshun]

Currently, commands entered by a player will appear in chat as if they were a normal chat message. Correctly handle chat messages prefixed with a "/" and reroute to command handler.

How this will be structured is yet to be seen—a system per command seems somewhat messy.

[caelunshun]

It might be a good idea to start by having commands take World as a parameter and running them sequentially at the end of the tick. There's no real need to run them in parallel, so this is a fine way to begin.

[DarkWeird]

Maybe use Fn fields for component and grouped commands by parameters?
Then you can expand it with future plugins ... Potentially, because it is part of ECS.

But introducing the system as a team sounds good for ECS and further expansion. You can implement the command macro for convenience.

[caelunshun]

With the Tonks rewrite, this will become a lot easier, because we will be able to schedule arbitrary systems on demand.

[Defman]

What would be involved in command support? Are we talking about a low-level system triggering all "/" or more in-depth with argument parsing like Mojang/bridgadier or both?

Further more if we are talking about a more fully featured command framework, should it be similar to bridgadier since thats how vanilla commands are handled.

[Defman]

I have been looking into implementing this and found it should support the following.

1. Syntax/usage generation for each command.
2. Branching based on Arguments. This will require the parsing of Args partially and not totally.
3. Description of each command.

struct Command<Args, F>
where
  Args: PartialParse,
  F: Fn(Args) -> CommandResult,
{
  args: PhantomData<Args>,
  function: F,
  description: Option<String>,
}

The arguments should be stored as some graph, and each node may have a command attached. The function attached to said command has the Argument which is the sum of all parent's arguments. Such that we can pass all previously partial parsed arguments from the graph as the total argument for the function.

struct Argument<T>
where
  T: Parse
{
  name: String,
  ty: PhantomData<T>,
}
impl<T, Args> PartialParse<T, Args> for Argument<T>
where
  T: Parse,
  Args: PartialParse
{
...
}