From 3934f0e59c7d05b8e59d4dfbe5611aa39a9bc10e Mon Sep 17 00:00:00 2001
From: Xavier Lau <xavier@inv.cafe>
Date: Sun, 13 Nov 2022 22:12:13 +0800
Subject: [PATCH] Optimize `cmd-impl`

---
 Cargo.lock                                    |  1 -
 bin/subalfred/src/command/impl/Cargo.toml     |  1 -
 .../src/command/impl/debug/Cargo.lock         | 53 +++++++++++++++++++
 bin/subalfred/src/command/impl/src/lib.rs     | 38 ++++++-------
 4 files changed, 70 insertions(+), 23 deletions(-)
 create mode 100644 bin/subalfred/src/command/impl/debug/Cargo.lock

diff --git a/Cargo.lock b/Cargo.lock
index c31f1623..84c880a8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -289,7 +289,6 @@ dependencies = [
 name = "cmd-impl"
 version = "0.9.0-rc16"
 dependencies = [
- "proc-macro2",
  "quote",
  "syn",
 ]
diff --git a/bin/subalfred/src/command/impl/Cargo.toml b/bin/subalfred/src/command/impl/Cargo.toml
index aedd6ff4..08d6ac07 100644
--- a/bin/subalfred/src/command/impl/Cargo.toml
+++ b/bin/subalfred/src/command/impl/Cargo.toml
@@ -13,7 +13,6 @@ version     = "0.9.0-rc16"
 proc-macro = true
 
 [dependencies]
-proc-macro2 = { version = "1.0" }
 quote       = { version = "1.0" }
 syn         = { version = "1.0", features = ["full"] }
 
diff --git a/bin/subalfred/src/command/impl/debug/Cargo.lock b/bin/subalfred/src/command/impl/debug/Cargo.lock
new file mode 100644
index 00000000..299c5aec
--- /dev/null
+++ b/bin/subalfred/src/command/impl/debug/Cargo.lock
@@ -0,0 +1,53 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "cmd-impl"
+version = "0.9.0-rc16"
+dependencies = [
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "cmd-impl-debug"
+version = "0.0.0"
+dependencies = [
+ "cmd-impl",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.47"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ea3d908b0e36316caf9e9e2c4625cdde190a7e6f440d794667ed17a1855e725"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbe448f377a7d6961e30f5955f9b8d106c3f5e449d493ee1b125c1d43c2b5179"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "syn"
+version = "1.0.103"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a864042229133ada95abf3b54fdc62ef5ccabe9515b64717bcb9a1919e59445d"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6ceab39d59e4c9499d4e5a8ee0e2735b891bb7308ac83dfb4e80cad195c9f6f3"
diff --git a/bin/subalfred/src/command/impl/src/lib.rs b/bin/subalfred/src/command/impl/src/lib.rs
index 7d063834..9cb924c6 100644
--- a/bin/subalfred/src/command/impl/src/lib.rs
+++ b/bin/subalfred/src/command/impl/src/lib.rs
@@ -1,31 +1,25 @@
 // proc-macro
 use proc_macro::TokenStream;
 // crates.io
-use proc_macro2::TokenStream as TokenStream2;
 use syn::*;
 
 /// Quickly define and implement a command containing serval subcommands.
 #[proc_macro_attribute]
 pub fn cmd(_: TokenStream, input: TokenStream) -> TokenStream {
-	let item_enum = syn::parse_macro_input!(input as ItemEnum);
+	let cmd_enum = syn::parse_macro_input!(input as ItemEnum);
 
 	// #[cfg(feature = "debug")]
-	// dbg!(&item_enum);
+	// dbg!(&cmd_enum);
 
-	let ItemEnum { attrs, vis, ident, variants, .. } = item_enum;
-	let variant_runs = variants
-		.iter()
-		.map(|v| v.ident.to_string().parse::<TokenStream2>().unwrap())
-		.map(|n| {
-			quote::quote! {
-				Self::#n(cmd) => { cmd.run() }
-			}
-		})
-		.collect::<Vec<_>>();
-	let variants = variants
+	let ItemEnum {
+		attrs: cmd_attrs, vis: cmd_vis, ident: cmd_name, variants: cmd_variants, ..
+	} = cmd_enum;
+	let cmd_variants_names =
+		cmd_variants.iter().map(|variant| variant.ident.clone()).collect::<Vec<_>>();
+	let cmd_variants = cmd_variants
 		.into_iter()
 		.map(|Variant { attrs, ident, .. }| {
-			let cmd = format!("{}Cmd", ident).parse::<TokenStream2>().unwrap();
+			let cmd = quote::format_ident!("{ident}Cmd");
 
 			quote::quote! {
 				#(#attrs)*
@@ -36,14 +30,16 @@ pub fn cmd(_: TokenStream, input: TokenStream) -> TokenStream {
 
 	quote::quote! {
 		#[derive(Debug, clap::Subcommand)]
-		#(#attrs)*
-		#vis enum #ident {
-			#(#variants,)*
+		#(#cmd_attrs)*
+		#cmd_vis enum #cmd_name {
+			#(#cmd_variants,)*
 		}
-		impl #ident {
-			#vis fn run(&self) -> crate::prelude::Result<()> {
+		impl #cmd_name {
+			#cmd_vis fn run(&self) -> crate::prelude::Result<()> {
 				match self {
-					#(#variant_runs,)*
+					#(
+						Self::#cmd_variants_names(cmd) => cmd.run(),
+					)*
 				}
 			}
 		}