Add build.rs to rebuild plugins, and a test plugin

plugins/Cargo.lock

@@ -112,6 +112,13 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "test_plugin"
+version = "0.1.0"
+dependencies = [
+ "plugin",
+]
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.0"

plugins/Cargo.toml

@@ -1,2 +1,2 @@
 [workspace]
-members = ["./json_language"]
+members = ["./json_language", "./test_plugin"]

plugins/test_plugin/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "test_plugin"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+plugin = { path = "../../crates/plugin" }
+
+[lib]
+crate-type = ["cdylib"]

plugins/test_plugin/src/lib.rs

@@ -0,0 +1,44 @@
+use plugin::prelude::*;
+
+#[export]
+pub fn noop() {}
+
+#[export]
+pub fn constant() -> u32 {
+    27
+}
+
+#[export]
+pub fn identity(i: u32) -> u32 {
+    i
+}
+
+#[export]
+pub fn add(a: u32, b: u32) -> u32 {
+    a + b
+}
+
+#[export]
+pub fn swap(a: u32, b: u32) -> (u32, u32) {
+    (b, a)
+}
+
+#[export]
+pub fn sort(mut list: Vec<u32>) -> Vec<u32> {
+    list.sort();
+    list
+}
+
+#[export]
+pub fn print(string: String) {
+    println!("to stdout: {}", string);
+    eprintln!("to stderr: {}", string);
+}
+
+// #[import]
+// fn mystery_number(input: u32) -> u32;
+
+// #[export]
+// pub fn and_back(secret: u32) -> u32 {
+//     mystery_number(secret)
+// }