add `export-png` primitive

1 files changed, 2 insertions, 0 deletions

diff --git a/src/lisp/error.rs b/src/lisp/error.rs
index f323bb8..9e9dc90 100644
--- a/src/lisp/error.rs
+++ b/src/lisp/error.rs
@@ -98,6 +98,7 @@ pub enum EvalError {
     DivByZero,
     TypeMismatch,
     NoFileName,
+    FileError(io::Error),
     AccessEmptyList,
     InvalidCoordinates((LispNumber, LispNumber)),
     AssertionError { expected: LispExpr, got: LispExpr },
@@ -126,6 +127,7 @@ 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::FileError(e) => write!(f, "file error: {}", e),
             Self::AccessEmptyList => write!(f, "attempted to access empty list"),
             Self::InvalidCoordinates((x, y)) => write!(f, "invalid coordinates: {} {}", x, y),
             Self::AssertionError { expected, got } => {