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

8 files changed, 36 insertions, 2 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
diff --git a/src/jscomp.sml b/src/jscomp.sml
index b66cdaf2..75cca425 100644
--- a/src/jscomp.sml
+++ b/src/jscomp.sml
@@ -194,6 +194,8 @@ fun process file =
         fun isNullable (t, _) =
             case t of
                 TOption _ => true
+              | TList _ => true
+              | TDatatype (_, ref (Option, _)) => true
               | TRecord [] => true
               | _ => false
 
diff --git a/src/mono_print.sml b/src/mono_print.sml
index ae11d3b8..71bc734a 100644
--- a/src/mono_print.sml
+++ b/src/mono_print.sml
@@ -55,9 +55,14 @@ fun p_typ' par env (t, _) =
                                             space,
                                             p_typ env t]) xcs,
                             string "}"]
-      | TDatatype (n, _) =>
+      | TDatatype (n, ref (dk, _)) =>
         ((if !debug then
-              string (#1 (E.lookupDatatype env n) ^ "__" ^ Int.toString n)
+              string (#1 (E.lookupDatatype env n) ^ "__" ^ Int.toString n  ^ "["
+                      ^ (case dk of
+                             Option => "Option"
+                           | Enum => "Enum"
+                           | Default => "Default")
+                      ^ "]")
           else
               string (#1 (E.lookupDatatype env n)))
          handle E.UnboundNamed _ => string ("UNBOUND_DATATYPE_" ^ Int.toString n))
diff --git a/src/monoize.sml b/src/monoize.sml
index 9654fd53..bdc8ef82 100644
--- a/src/monoize.sml
+++ b/src/monoize.sml
@@ -1245,6 +1245,18 @@ fun monoExp (env, st, fm) (all as (e, loc)) =
                                       loc)), loc)), loc),
                  fm)
             end
+          | L.ECApp ((L.EFfi ("Basis", "current"), _), t) =>
+            let
+                val t = monoType env t
+            in
+                ((L'.EAbs ("src", (L'.TSource, loc),
+                           (L'.TFun ((L'.TRecord [], loc), t), loc),
+                           (L'.EAbs ("_", (L'.TRecord [], loc), t,
+                                     (L'.EFfiApp ("Basis", "current",
+                                                  [(L'.ERel 1, loc)]),
+                                      loc)), loc)), loc),
+                 fm)
+            end
 
           | L.EFfiApp ("Basis", "spawn", [e]) =>
             let
diff --git a/src/settings.sml b/src/settings.sml
index e5b42abc..b1c5948f 100644
--- a/src/settings.sml
+++ b/src/settings.sml
@@ -98,6 +98,7 @@ fun isEffectful x = S.member (!effectful, x)
 
 val clientBase = basis ["get",
                         "set",
+                        "current",
                         "alert",
                         "recv",
                         "sleep",
@@ -125,6 +126,7 @@ val basisM = foldl (fn ((k, v : string), m) => M.insert (m, ("Basis", k), v)) M.
 
 val jsFuncsBase = basisM [("alert", "alert"),
                           ("get_client_source", "sg"),
+                          ("current", "scur"),
                           ("htmlifyBool", "bs"),
                           ("htmlifyFloat", "ts"),
                           ("htmlifyInt", "ts"),