From 881902f2c7b4a690dd512b750cbc82f2d954f1e9 Mon Sep 17 00:00:00 2001
From: artoy <ryota5884@icloud.com>
Date: Thu, 24 Aug 2023 23:58:42 +0900
Subject: [PATCH] update tests

---
 src/test/list/nth.imp | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/src/test/list/nth.imp b/src/test/list/nth.imp
index 59dbff12..6ba96e1e 100644
--- a/src/test/list/nth.imp
+++ b/src/test/list/nth.imp
@@ -1,7 +1,24 @@
-nth(l, n) {
+mklist(n) {
+    if n = 0 then Nil else {
+        let h = _ in
+        let m = n + -1 in
+        let t = mkref mklist(m) in
+        Cons h t
+    }
+}
 
+nth(l, n) {
+    match l with
+      Nil -> fail
+    | Cons h t -> {
+        let m = n + -1 in
+        if n = 1 then h else nth(*t, m)
+    }
 }
 
 {
-
+    let n = ( _ : ~ >= 1) in
+    let k = ( _ : ~ >= 1 /\ ~ <= n) in
+    let l = mklist(n) in
+    nth(l, k)
 }
\ No newline at end of file