refactor(tvix/eval): impl Display for ErrorKind r/5639

This just shuffles the Display implementations around so that
ErrorKind itself is displayable, which is useful in some situations
where errors under construction need to be type-converted.

Change-Id: I7b633d03d0dc34f345c4f20676e0023ecb1db0c4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7802
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: edef <edef@edef.eu>
Tested-by: BuildkiteCI

1 files changed, 8 insertions, 2 deletions

diff --git a/tvix/eval/src/errors.rs b/tvix/eval/src/errors.rs
index 2cef36f757..416a4b23c0 100644
--- a/tvix/eval/src/errors.rs
+++ b/tvix/eval/src/errors.rs
@@ -223,9 +223,9 @@ pub struct Error {
     pub span: Span,
 }
 
-impl Display for Error {
+impl Display for ErrorKind {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match &self.kind {
+        match &self {
             ErrorKind::Throw(msg) => write!(f, "error thrown: {}", msg),
             ErrorKind::Abort(msg) => write!(f, "evaluation aborted: {}", msg),
             ErrorKind::AssertionFailed => write!(f, "assertion failed"),
@@ -409,6 +409,12 @@ to a missing value in the attribute set(s) included via `with`."#,
     }
 }
 
+impl Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.kind)
+    }
+}
+
 pub type EvalResult<T> = Result<T, Error>;
 
 /// Human-readable names for rnix syntaxes.