More cleanup during review

crates/plugin_runtime/README.md

@@ -39,10 +39,19 @@ Here's an example Rust Wasm plugin that doubles the value of every float in a `V
 ```rust
 use plugin::prelude::*;
 
-#[bind]
+#[export]
 pub fn double(mut x: Vec<f64>) -> Vec<f64> {
     x.into_iter().map(|x| x * 2.0).collect()
 }
 ```
 
-All the serialization code is automatically generated by `#[bind]`.
+All the serialization code is automatically generated by `#[export]`.
+
+You can specify functions that must be defined host-side by using the `#[import]` attribute. This attribute must be attached to a function signature:
+
+```rust
+#[import]
+fn run(command: String) -> Vec<u8>;
+```
+
+The `#[import]` macro will generate a function body that performs the proper serialization/deserialization needed to call out to the host rust runtime. Note that the same ABI is used for both `#[import]` and `#[export]`.

crates/plugin_runtime/build.rs

@@ -5,7 +5,7 @@ fn main() {
     let base = Path::new("../../plugins");
 
     // println!("cargo:rerun-if-changed=../../plugins/*");
-    println!("cargo:warning=Rebuilding plugins...");
+    println!("cargo:warning=Precompiling plugins...");
 
     let _ = std::fs::remove_dir_all(base.join("bin"));
     let _ =
@@ -27,7 +27,6 @@ fn main() {
 
     let binaries = std::fs::read_dir(base.join("target/wasm32-wasi/release"))
         .expect("Could not find compiled plugins in target");
-    println!("cargo:warning={:?}", binaries);
 
     let engine = create_engine();
 

crates/plugin_runtime/src/lib.rs

@@ -36,8 +36,6 @@ mod tests {
                 .host_function_async("import_half", |a: u32| async move { a / 2 })
                 .unwrap()
                 .host_function_async("command_async", |command: String| async move {
-                    // TODO: actual thing
-                    dbg!(&command);
                     let mut args = command.split(' ');
                     let command = args.next().unwrap();
                     smol::process::Command::new(command)
@@ -45,10 +43,7 @@ mod tests {
                         .output()
                         .await
                         .ok()
-                        .map(|output| {
-                            dbg!("Did run command!");
-                            output.stdout
-                        })
+                        .map(|output| output.stdout)
                 })
                 .unwrap()
                 .init(