chore: catch err, move out helpers

src/channel.rs

@@ -2,7 +2,7 @@ use mlua::{Lua, MultiValue};
 use tokio::{sync::{mpsc, broadcast}, net::{TcpListener, TcpStream}, io::{AsyncWriteExt, AsyncReadExt}};
 use tracing::{debug, error};
 
-use crate::runtime::{prepare_lua_runtime, pretty_lua};
+use crate::{runtime::register_builtin_fn, helpers::pretty_lua};
 
 
 pub struct ControlChannel {
@@ -50,7 +50,11 @@ impl ControlChannel {
 
 	async fn process(&mut self, mut stream: TcpStream) {
 		let mut lua = Lua::new();
-		prepare_lua_runtime(&mut lua, self.source.clone());
+		if let Err(e) = register_builtin_fn(&mut lua, self.source.clone()) {
+			error!("could not prepare Lua runtime: {}", e);
+			return;
+		}
+
 		self.source.send(
 			format!("LuaJit 5.2 via rlua inside process #{}\n@> ", std::process::id())
 		).unwrap();
@@ -60,6 +64,7 @@ impl ControlChannel {
 
 				rx = stream.read_u8() => match rx { // FIXME is read_exact cancelable?
 					Ok(c) => {
+						// TODO move this "lua repl" code outside of here!
 						if !c.is_ascii() {
 							debug!("character '{}' is not ascii", c);
 							break;

src/helpers.rs

@@ -0,0 +1,25 @@
+use mlua::{Value, Table};
+
+pub fn pretty_lua(val: Value) -> String {
+	// TODO there must be some builtin to do this, right???
+	match val {
+		Value::Nil => "nil".into(),
+		Value::Boolean(b) => if b { "true".into() } else { "false".into() },
+		Value::LightUserData(x) => format!("LightUserData({:?})", x),
+		Value::Integer(n) => format!("{}", n),
+		Value::Number(n) => format!("{:.3}", n),
+		Value::String(s) => s.to_str().expect("string is not str").into(),
+		Value::Table(t) => try_serialize_table(&t),
+		Value::Function(f) => format!("Function({:?}", f),
+		Value::Thread(t) => format!("Thread({:?})", t),
+		Value::UserData(x) => format!("UserData({:?})", x),
+		Value::Error(e) => format!("Error({:?}) : {}", e, e.to_string()),
+	}
+}
+
+fn try_serialize_table(t: &Table) -> String {
+	match serde_json::to_string(t) {
+		Ok(txt) => txt,
+		Err(_e)  => format!("{:?}", t),
+	}
+}

src/lib.rs

@@ -1,5 +1,6 @@
 mod runtime;
 mod channel;
+mod helpers;
 
 use channel::ControlChannel;
 use tracing::{error, debug};
@@ -41,4 +42,3 @@ async fn main() {
 		}
 	}
 }
-