More errors!

1 files changed, 48 insertions, 0 deletions

diff --git a/src/error.rs b/src/error.rs
new file mode 100644
index 0000000..277be5f
--- /dev/null
+++ b/src/error.rs
@@ -0,0 +1,48 @@
+use std::fmt;
+use std::path::PathBuf;
+use crate::vm::{Op, Value};
+
+#[derive(Debug)]
+pub enum ErrorKind {
+    TypeError(Op, Vec<Value>),
+    AssertFailed(Value, Value),
+    SyntaxError(usize),
+}
+
+#[derive(Debug)]
+pub struct Error {
+    pub kind: ErrorKind,
+    pub file: PathBuf,
+    pub line: usize,
+    pub message: Option<String>,
+}
+
+impl fmt::Display for ErrorKind {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            ErrorKind::TypeError(op, values) => {
+                let values = values
+                    .iter()
+                    .fold(String::new(), |a, v| { format!("{}, {:?}", a, v) });
+                write!(f, "Cannot apply {:?} to values {}", op, values)
+            }
+            ErrorKind::AssertFailed(a, b) => {
+                write!(f, "Assertion failed, {:?} != {:?}.", a, b)
+            }
+            ErrorKind::SyntaxError(line) => {
+                write!(f, "Syntax error on line {}", line)
+            }
+        }
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let message = match &self.message {
+            Some(s) => format!("\n{}", s),
+            None => String::from(""),
+        };
+        write!(f, "{:?}:{} [Runtime Error] {}{}", self.file, self.line, self.kind, message)
+    }
+}
+