From d177285a761de33b86fcbde72fd718137bfa6f86 Mon Sep 17 00:00:00 2001
From: Xander <xander@biltopia.org>
Date: Thu, 17 Aug 2023 22:08:21 +0200
Subject: Add valid/unvalid type, replacement of optional

---
 lib/DATS/valid.dats | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
 create mode 100644 lib/DATS/valid.dats

(limited to 'lib/DATS/valid.dats')

diff --git a/lib/DATS/valid.dats b/lib/DATS/valid.dats
new file mode 100644
index 0000000..f4ea0aa
--- /dev/null
+++ b/lib/DATS/valid.dats
@@ -0,0 +1,15 @@
+#define ATS_DYNLOADFLAG 0
+staload "lib/SATS/valid.sats"
+
+assume valid(a:t@ype,b:bool) = (a,bool b) 
+
+implement{a} create_valid(value : a) = (value,true)
+
+// Create unvalid value by casting null pointer to type.
+implement{a} create_unvalid() = let
+  staload UN = "prelude/SATS/unsafe.sats"
+in
+  ($UN.ptr0_get<a>(the_null_ptr),false) //UNSAFE:
+end
+
+implement{a} unwrap_valid(v) = v.0
-- 
cgit v1.2.3