From d7dab8e4b0474f393fa75bc0fe3b3c5c6458389e Mon Sep 17 00:00:00 2001
From: Emi Simpson <emi@alchemi.dev>
Date: Sun, 12 Feb 2023 16:57:23 -0500
Subject: [PATCH] Make note use lazy evaluation

---
 emis_funky_funktions.py | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/emis_funky_funktions.py b/emis_funky_funktions.py
index 1fec916..802b522 100644
--- a/emis_funky_funktions.py
+++ b/emis_funky_funktions.py
@@ -530,21 +530,24 @@ def bind_opt(f: Callable[[A], Option[B]], o: Option[A]) -> Option[B]:
 			return f(val)
 		case none:
 			return none
-def note(e: B, o: Option[A]) -> 'Result[A, B]':
+def note(e: Callable[[], B], o: Option[A]) -> 'Result[A, B]':
 	"""
 	Convert an `Option` to a `Result` by attaching an error to the `None` variants
 
-	>>> note('woops!', Some(1))
+	`e` should be a zero-argument function which produces the desired error value.	It
+	will be called if and only if `o` is `None`.
+
+	>>> note(lambda: 'woops!', Some(1))
 	Ok(1)
 
-	>>> note('woops!', None)
+	>>> note(lambda: 'woops!', None)
 	Err('woops!')
 	"""
 	match o:
 		case Some(val):
 			return Ok(val)
 		case None:
-			return Err(e)
+			return Err(e())
 
 def unwrap_opt(r: Option[A]) -> A:
 	"""