Macro clishe::commands

macro_rules! commands {
    (
        $(
            $(#[$meta:meta])?
            $name:ident(
                $self:ident,
                $context:ident: &mut $context_ty:ty
            ) -> Result<$ret_ty:ty> $body:block struct {
                $($(#[$sub_meta:meta])? $field_name:ident: $field_ty:ty,)*
            },
        ) *
    ) => { ... };
}

Defines a DSL for implementing a leaf in our command hierarchy.

Those leaf commands implement concrete logic which can change the state of the context, return a desired output, or trigger any kind of side-effect whatsoever. They contain the meat of our cli. They can be attached to dispatchers or parsed directly, as any ::clap::App can.

The DSL is as follows:

use ::clishe::prelude::*;
pub struct Context(u64);
commands! {
//    vvvv any clap attribute available on clap commands are available here
    #[clap(author = "Louis Feuvrier <mqnfred@gmail.com>")]
//  vvvvv name of the command in the code
    Store(self,
//        ^^^^ fixed, points to the clap structure containing the arguments

//              vvv can be any identifier, but not _ itself, if unused put _ctx
    Store(self, ctx: &mut
//                   ^^^^ mutability has been decided already, this is mandatory

//                        vvvvvvvvvvvvvv any path to a structure of any kind if valid
    Store(self, ctx: &mut crate::Context) -> Result
//                                           ^^^^^^ ::anyhow::Result, from prelude

//             return type of the command hierarchy vv  v curly brackets
    Store(self, ctx: &mut crate::Context) -> Result<()> {
        Ok(ctx.0 = self.amount) // do anything to context
//      ^^^  return whatever  ^
    } struct { // mandatory
//        vvvv any clap attribute available on clap command fields are available here
        #[clap(about = "The number to store in our context")]
        number: String,
//      ^^^^^^^^^^^^^^ see clap derive library for more context on how types are interpreted
    },
    ^^ curly brackets, with a mandatory comma
}