procmacro

Chapter09/Cargo.toml

@@ -7,6 +7,7 @@ flame = "0.2"
 rand = "0.4.2"
 requests = "0.0.30"
 rusty-machine = "0.5.4"
+procmacro = { path = "procmacro" }
 
 [[bin]]
 name = "performance_release_mode"
@@ -91,3 +92,7 @@ path = "metaprogramming_grammar.rs"
 [[bin]]
 name = "metaprogramming_ebnf"
 path = "metaprogramming_ebnf.rs"
+
+[[bin]]
+name = "metaprogramming_procmacro"
+path = "metaprogramming_procmacro.rs"

Chapter09/metaprogramming_procmacro.rs

@@ -0,0 +1,7 @@
+#![feature(proc_macro_non_items)]
+#![feature(use_extern_macros)]
+extern crate procmacro;
+
+fn main() {
+   let _ = procmacro::f!();
+}

Chapter09/procmacro/.gitignore

@@ -0,0 +1,2 @@
+Cargo.lock
+target

Chapter09/procmacro/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "procmacro"
+version = "1.0.0"
+
+[dependencies]
+syn = "0.12"
+quote = "0.4"
+
+[lib]
+proc-macro = true

Chapter09/procmacro/src/lib.rs

@@ -0,0 +1,15 @@
+#![feature(proc_macro)]
+#![crate_type = "proc-macro"]
+extern crate proc_macro;
+extern crate syn;
+#[macro_use] extern crate quote;
+use proc_macro::TokenStream;
+
+#[proc_macro]
+pub fn f(input: TokenStream) -> TokenStream {
+    assert!(input.is_empty());
+
+    (quote! {
+       1 + 2
+    }).into()
+}