From 6c2d5cc84acba7b7cfe6f40edbd1921002dd17c1 Mon Sep 17 00:00:00 2001
From: Alex Bethel <abethel@cs.nmt.edu>
Date: Fri, 4 Jun 2021 18:56:26 -0500
Subject: [PATCH] Prettier error handling

---
 src/repl.rs | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/repl.rs b/src/repl.rs
index a442a97..00a9c89 100644
--- a/src/repl.rs
+++ b/src/repl.rs
@@ -20,13 +20,20 @@ pub fn repl() {
                     Ok(ast) => {
                         println!("{:?}", ast);
                         println!("{:?}", env.eval_items(&ast));
-                    },
+                    }
                     Err(e) => {
                         println!(
                             "Error `{:?}` occured at span: {:?} = `{:?}`",
                             e.kind,
                             e.position.clone(),
-                            line.slice(e.position)
+                            line.slice(e.position.clone())
+                        );
+
+                        println!(" | {}", line);
+                        println!(
+                            "   {}{}-- Here",
+                            " ".repeat(e.position.start),
+                            "^".repeat((e.position.end - e.position.start).max(1))
                         );
                     }
                 }