From d4cbcb8b99849830ad55704f7ef9ec6a05e74689 Mon Sep 17 00:00:00 2001
From: Philippe Pittoli <karchnu@karchnu.fr>
Date: Fri, 19 Jan 2024 19:31:25 +0100
Subject: [PATCH] Fix position when an error occurs in `sat`.

---
 src/GenericParser/Parser.purs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/GenericParser/Parser.purs b/src/GenericParser/Parser.purs
index 37ee244..2c1a604 100644
--- a/src/GenericParser/Parser.purs
+++ b/src/GenericParser/Parser.purs
@@ -121,8 +121,10 @@ try p = Parser p'
                      _       -> failureError position error
 
 sat :: forall e. (Char -> Boolean) -> Parser e Char
-sat p = do x <- item
-           if p x then pure x else empty
+sat p = do
+           pos <- current_position
+           x <- item
+           if p x then pure x else Parser \input -> failure pos
 
 digit :: forall e. Parser e Char
 digit = sat isDigit