Corify cfold

5 files changed, 10 insertions, 1 deletions

diff --git a/src/core.sml b/src/core.sml
index 613e0c41..07ab4641 100644
--- a/src/core.sml
+++ b/src/core.sml
@@ -52,6 +52,7 @@ datatype con' =
 
        | CRecord of kind * (con * con) list
        | CConcat of con * con
+       | CFold of kind * kind
 
 withtype con = con' located
 
diff --git a/src/core_print.sml b/src/core_print.sml
index a3fde909..7242e720 100644
--- a/src/core_print.sml
+++ b/src/core_print.sml
@@ -134,6 +134,7 @@ fun p_con' par env (c, _) =
                                               string "++",
                                               space,
                                               p_con env c2])
+      | CFold _ => string "fold"
         
 and p_con env = p_con' false env
 
diff --git a/src/core_util.sml b/src/core_util.sml
index b3e266af..66918863 100644
--- a/src/core_util.sml
+++ b/src/core_util.sml
@@ -143,6 +143,12 @@ fun mapfoldB {kind = fk, con = fc, bind} =
                          S.map2 (mfc ctx c2,
                               fn c2' =>
                                  (CConcat (c1', c2'), loc)))
+              | CFold (k1, k2) =>
+                S.bind2 (mfk k1,
+                         fn k1' =>
+                            S.map2 (mfk k2,
+                                    fn k2' =>
+                                       (CFold (k1', k2'), loc)))
     in
         mfc
     end
diff --git a/src/corify.sml b/src/corify.sml
index b4a7108e..94654064 100644
--- a/src/corify.sml
+++ b/src/corify.sml
@@ -244,7 +244,7 @@ fun corifyCon st (c, loc) =
       | L.CRecord (k, xcs) =>
         (L'.CRecord (corifyKind k, map (fn (c1, c2) => (corifyCon st c1, corifyCon st c2)) xcs), loc)
       | L.CConcat (c1, c2) => (L'.CConcat (corifyCon st c1, corifyCon st c2), loc)
-      | L.CFold _ => raise Fail "Corify CFold"
+      | L.CFold (k1, k2) => (L'.CFold (corifyKind k1, corifyKind k2), loc)
 
 fun corifyExp st (e, loc) =
     case e of
diff --git a/src/monoize.sml b/src/monoize.sml
index 310abc6a..f8a0d96e 100644
--- a/src/monoize.sml
+++ b/src/monoize.sml
@@ -71,6 +71,7 @@ fun monoType env (all as (c, loc)) =
 
           | L.CRecord _ => poly ()
           | L.CConcat _ => poly ()
+          | L.CFold _ => poly ()
     end
 
 val dummyExp = (L'.EPrim (Prim.Int 0), E.dummySpan)