1 files changed, 13 insertions, 1 deletions
diff --git a/src/node.rs b/src/node.rs
index 3bcd73b..b63270e 100644
--- a/src/node.rs
+++ b/src/node.rs
@@ -5,6 +5,18 @@ use crate::library;
 use crate::library::*;
 use crate::types::{Type, TypeSignature};
 
+#[derive(Debug, Copy, Clone)]
+pub enum CompileError {
+    MissingArguments,
+    Codegen(fmt::Error),
+}
+
+impl From<fmt::Error> for CompileError {
+    fn from(v: fmt::Error) -> Self {
+        Self::Codegen(v)
+    }
+}
+
 /// an instantiable Node, parametrized by its connected input types
 #[enum_dispatch]
 pub trait ConcreteNode {
@@ -24,7 +36,7 @@ pub trait ConcreteNode {
         inputs: Vec<Option<String>>,
         outputs: Vec<String>,
         f: &mut dyn fmt::Write,
-    ) -> fmt::Result;
+    ) -> Result<(), CompileError>;
 
     fn show_body(&mut self, ui: &mut egui::Ui) -> egui::Response {
         ui.response()