1 files changed, 19 insertions, 6 deletions

diff --git a/src/lisp/error.rs b/src/lisp/error.rs
index 6d28c22..53681d8 100644
--- a/src/lisp/error.rs
+++ b/src/lisp/error.rs
@@ -3,19 +3,23 @@ use crate::lisp::{
     lex::{Span, SpanDisplay},
 };
 
-use std::fmt;
+use std::{fmt, io};
 
-#[derive(Debug, PartialEq, Clone)]
+#[derive(Debug)]
 pub enum LispError {
     Parse(ParseError),
     Eval(EvalError),
+    Stringified(String),
 }
 
+impl std::error::Error for LispError {}
+
 impl fmt::Display for LispError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
             Self::Parse(p) => write!(f, "parse error: {}", p.kind),
             Self::Eval(e) => write!(f, "eval error: {}", e),
+            Self::Stringified(s) => write!(f, "{}", s),
         }
     }
 }
@@ -30,9 +34,12 @@ impl ParseError {
     pub fn new(span: Span, kind: ParseErrorKind) -> Self {
         Self { span, kind }
     }
-    pub fn display(&self, text: &str) -> String {
-        let SpanDisplay { line, col, .. } = SpanDisplay::highlight_span(self.span, text);
-        format!("line {}, col {}: {}", line, col, self.kind)
+    pub fn display(&self, text: &str, file_name: &str) -> String {
+        let SpanDisplay { line, col, .. } = SpanDisplay::highlight_span(self.span, text, file_name);
+        format!(
+            "in file `{}`; line {}, col {}: {}",
+            file_name, line, col, self.kind
+        )
     }
 }
 
@@ -82,7 +89,7 @@ impl From<ParseError> for LispError {
     }
 }
 
-#[derive(Debug, PartialEq, Clone)]
+#[derive(Debug)]
 pub enum EvalError {
     ArgumentCount(Arity),
     BadForm,
@@ -90,7 +97,10 @@ pub enum EvalError {
     DivByZero,
     TypeMismatch,
     NoFileName,
+    AccessEmptyList,
+    ScriptLoadError(io::Error),
     CustomInternal(&'static str),
+    Custom(String),
 }
 
 impl fmt::Display for EvalError {
@@ -113,7 +123,10 @@ impl fmt::Display for EvalError {
             Self::TypeMismatch => write!(f, "mismatched types"),
             Self::DivByZero => write!(f, "attempt to divide by zero"),
             Self::NoFileName => write!(f, "no file name specified"),
+            Self::AccessEmptyList => write!(f, "attempted to access empty list"),
+            Self::ScriptLoadError(s) => write!(f, "error while loading script: {}", s),
             Self::CustomInternal(s) => write!(f, "{}", s),
+            Self::Custom(s) => write!(f, "error: {}", s),
         }
     }
 }