From 729df92dd28ed2aff37bd2c8e5eab2ae8c01d53d Mon Sep 17 00:00:00 2001
From: victor koenders <gpg@trangar.com>
Date: Wed, 10 Aug 2022 20:45:01 +0200
Subject: [PATCH] Added `as_async` to the `FnBuilder`

---
 src/generate/generate_fn.rs | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/generate/generate_fn.rs b/src/generate/generate_fn.rs
index 5b7275d..2ec1cdf 100644
--- a/src/generate/generate_fn.rs
+++ b/src/generate/generate_fn.rs
@@ -9,6 +9,7 @@ pub struct FnBuilder<'a, P> {
     parent: &'a mut P,
     name: String,
 
+    is_async: bool,
     lifetimes: Vec<(String, Vec<String>)>,
     generics: Vec<(String, Vec<String>)>,
     self_arg: FnSelfArg,
@@ -22,6 +23,7 @@ impl<'a, P: FnParent> FnBuilder<'a, P> {
         Self {
             parent,
             name: name.into(),
+            is_async: false,
             lifetimes: Vec::new(),
             generics: Vec::new(),
             self_arg: FnSelfArg::None,
@@ -47,6 +49,22 @@ impl<'a, P: FnParent> FnBuilder<'a, P> {
         self
     }
 
+    /// Make the function async
+    ///
+    /// ```no_run
+    /// # use virtue::prelude::Generator;
+    /// # let mut generator: Generator = unsafe { std::mem::zeroed() };
+    /// generator
+    ///     .r#impl()
+    ///     .generate_fn("foo") // fn foo()
+    ///     .as_async(); // async fn foo()
+    /// ```
+    #[must_use]
+    pub fn as_async(mut self) -> Self {
+        self.is_async = true;
+        self
+    }
+
     /// Add a lifetime parameter.
     ///
     /// `dependencies` are the lifetime dependencies of the given lifetime.
@@ -199,6 +217,7 @@ impl<'a, P: FnParent> FnBuilder<'a, P> {
         let FnBuilder {
             parent,
             name,
+            is_async,
             lifetimes,
             generics,
             self_arg,
@@ -213,6 +232,9 @@ impl<'a, P: FnParent> FnBuilder<'a, P> {
         if vis == Visibility::Pub {
             builder.ident_str("pub");
         }
+        if is_async {
+            builder.ident_str("async");
+        }
         builder.ident_str("fn");
         builder.ident_str(name);