From dc29847cd3b37fd234d32f81f088a2e8f0031aff Mon Sep 17 00:00:00 2001
From: b1ek <me@blek.codes>
Date: Tue, 22 Aug 2023 22:14:41 +1000
Subject: [PATCH] add position annotation to errors

---
 src/lib.rs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 5f2cd79..22c73ba 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -21,14 +21,14 @@ pub fn eval_mem(bf_str: &&str, mem: &mut [u8], pointer: &mut usize) -> Result<()
 
         if char == '>' {
             if (*pointer) + 1 == 30000 {
-                return Err("Attempt to increase pointer exceeding memory size".into());
+                return Err(format!("Attempt to increase pointer exceeding memory size ({})", pos));
             }
             *pointer += 1;
             continue
         }
         if char == '<' {
             if *pointer == 0 {
-                return Err("Attempt to reduce pointer to less than 1".into());
+                return Err(format!("Attempt to reduce pointer to less than 1 ({})", pos));
             }
             *pointer -= 1;
             continue
@@ -73,7 +73,7 @@ pub fn eval_mem(bf_str: &&str, mem: &mut [u8], pointer: &mut usize) -> Result<()
         if char == ']' {
 
             if loop_stack.len() == 0 {
-                return Err(format!("Invalid loop at position {pos}"));
+                return Err(format!("Unmatched ']' ({})", pos));
             }
 
             if mem[*pointer] == 0 {
@@ -87,7 +87,7 @@ pub fn eval_mem(bf_str: &&str, mem: &mut [u8], pointer: &mut usize) -> Result<()
     }
 
     if loop_stack.len() != 0 {
-        return Err(format!("Unclosed loop at position {}", loop_stack.last().unwrap()));
+        return Err(format!("Unmatched '[' ({})", loop_stack.last().unwrap()));
     }
 
     Ok(())