Start of Option; Basis.current; fix missed cases in Jscomp.isNullable

4 files changed, 13 insertions, 0 deletions

diff --git a/lib/js/urweb.js b/lib/js/urweb.js
index 6c974948..efd94bb9 100644
--- a/lib/js/urweb.js
+++ b/lib/js/urweb.js
@@ -210,6 +210,9 @@ function sb(x,y) {
     return {sources : union(xr.sources, yr.sources), data : yr.data};
   };
 }
+function scur(s) {
+  return s().data;
+}
 
 function lastParent() {
   var pos = document;
diff --git a/lib/ur/basis.urs b/lib/ur/basis.urs
index d3fbe037..50909804 100644
--- a/lib/ur/basis.urs
+++ b/lib/ur/basis.urs
@@ -107,6 +107,7 @@ val get : t ::: Type -> source t -> transaction t
 con signal :: Type -> Type
 val signal_monad : monad signal
 val signal : t ::: Type -> source t -> signal t
+val current : t ::: Type -> signal t -> transaction t
 
 
 (** HTTP operations *)
diff --git a/lib/ur/option.ur b/lib/ur/option.ur
new file mode 100644
index 00000000..cb2a6b57
--- /dev/null
+++ b/lib/ur/option.ur
@@ -0,0 +1,6 @@
+datatype t = datatype Basis.option
+
+fun isSome [a] x =
+    case x of
+        None => False
+      | Some _ => True
diff --git a/lib/ur/option.urs b/lib/ur/option.urs
new file mode 100644
index 00000000..97e52fda
--- /dev/null
+++ b/lib/ur/option.urs
@@ -0,0 +1,3 @@
+datatype t = datatype Basis.option
+
+val isSome : a ::: Type -> t a -> bool