chore(tvix/eval): return parse errors out of eval::interpret

Change-Id: I14f25b9c85260c68be38abf07ed80121ead60c7b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6224
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>

tvix/eval/src/errors.rs

@@ -31,6 +31,8 @@ pub enum Error {
 
     // Unknown variable in dynamic scope (with, rec, ...).
     UnknownDynamicVariable(String),
+
+    ParseErrors(Vec<rnix::parser::ParseError>),
 }
 
 impl Display for Error {

tvix/eval/src/eval.rs

@@ -2,14 +2,20 @@ use std::path::PathBuf;
 
 use rnix::{self, types::TypedNode};
 
-use crate::{errors::EvalResult, value::Value};
+use crate::{
+    errors::{Error, EvalResult},
+    value::Value,
+};
 
 pub fn interpret(code: &str, location: Option<PathBuf>) -> EvalResult<Value> {
     let ast = rnix::parse(code);
 
     let errors = ast.errors();
     if !errors.is_empty() {
-        todo!()
+        for err in &errors {
+            eprintln!("parse error: {}", err);
+            return Err(Error::ParseErrors(errors));
+        }
     }
 
     if std::env::var("TVIX_DISPLAY_AST").is_ok() {