From 3433f378b1cd783aafcc24e8bcc5bac5e8497246 Mon Sep 17 00:00:00 2001
From: Robin Krahl <robin.krahl@ireas.org>
Date: Wed, 8 Jan 2020 11:35:19 +0000
Subject: Handle doc comments and empty variants in the Command! macro
This patch introduces two changes to the Command! macro:
- We allow variants without fields so that we no longer have to define
empty *Args structs just for the Command! macro.
- We allow doc comments so that we can document commands without a
separate *Args struct.
---
src/arg_util.rs | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/src/arg_util.rs b/src/arg_util.rs
index 8cd8fe5..c72d89b 100644
--- a/src/arg_util.rs
+++ b/src/arg_util.rs
@@ -24,12 +24,21 @@ macro_rules! count {
}
}
+/// Translate an optional source into an optional destination.
+macro_rules! tr {
+ ($dst:tt, $src:tt) => {
+ $dst
+ };
+ ($dst:tt) => {};
+}
+
macro_rules! Command {
- ( $name:ident, [ $( $var:ident($inner:ident) => $exec:expr, ) *] ) => {
+ ( $name:ident, [ $( $(#[$doc:meta])* $var:ident$(($inner:ty))? => $exec:expr, ) *] ) => {
#[derive(Debug, PartialEq, structopt::StructOpt)]
pub enum $name {
$(
- $var($inner),
+ $(#[$doc])*
+ $var$(($inner))?,
)*
}
@@ -41,7 +50,7 @@ macro_rules! Command {
) -> crate::Result<()> {
match self {
$(
- $name::$var(args) => $exec(ctx, args),
+ $name::$var$((tr!(args, $inner)))? => $exec(ctx $(,tr!(args, $inner))?),
)*
}
}
--
cgit v1.2.3