Make SELECT FROM clauses optional

2 files changed, 93 insertions, 36 deletions

diff --git a/lib/ur/basis.urs b/lib/ur/basis.urs
index c75eea1b..8388e107 100644
--- a/lib/ur/basis.urs
+++ b/lib/ur/basis.urs
@@ -292,6 +292,7 @@ val sql_subset_concat : big1 ::: {{Type}} -> little1 ::: {{Type}}
 
 con sql_from_items :: {{Type}} -> {{Type}} -> Type
 
+val sql_from_nil : free ::: {{Type}} -> sql_from_items free []
 val sql_from_table : free ::: {{Type}} -> t ::: Type -> fs ::: {Type}
                      -> fieldsOf t fs -> name :: Name
                      -> t -> sql_from_items free [name = fs]
diff --git a/src/monoize.sml b/src/monoize.sml
index 5aebad63..9799ae95 100644
--- a/src/monoize.sml
+++ b/src/monoize.sml
@@ -1891,8 +1891,14 @@ fun monoExp (env, st, fm) (all as (e, loc)) =
 										   ^ ".uw_"
 										   ^ x'))
                                                                            xts)) stables),
-                                           sc " FROM ",
-                                           gf "From",
+                                           (L'.ECase (gf "From",
+                                                      [((L'.PPrim (Prim.String ""), loc),
+                                                        sc ""),
+                                                       ((L'.PVar ("x", s), loc),
+                                                        strcat [sc " FROM ",
+                                                                (L'.ERel 0, loc)])],
+                                                      {disc = s,
+                                                       result = s}), loc),
                                            (L'.ECase (gf "Where",
                                                       [((L'.PPrim (Prim.String "TRUE"), loc),
                                                         sc ""),
@@ -2048,6 +2054,8 @@ fun monoExp (env, st, fm) (all as (e, loc)) =
           | L.ECApp ((L.EFfi ("Basis", "fieldsOf_view"), _), _) =>
             ((L'.ERecord [], loc), fm)
 
+          | L.ECApp ((L.EFfi ("Basis", "sql_from_nil"), _), _) =>
+            ((L'.EPrim (Prim.String ""), loc), fm)
           | L.ECApp ((L.EApp ((L.ECApp ((L.ECApp ((L.ECApp ((L.EFfi ("Basis", "sql_from_table"), _), _),
                                                    _), _), _), _), _), _), _),
                      (L.CName name, _)) =>
@@ -2078,9 +2086,18 @@ fun monoExp (env, st, fm) (all as (e, loc)) =
             in
                 ((L'.EAbs ("tab1", s, (L'.TFun (s, s), loc),
                            (L'.EAbs ("tab2", s, s,
-                                     strcat [(L'.ERel 1, loc),
-                                             (L'.EPrim (Prim.String ", "), loc),
-                                             (L'.ERel 0, loc)]), loc)), loc),
+                                     (L'.ECase ((L'.ERecord [("1", (L'.ERel 1, loc), s),
+                                                             ("2", (L'.ERel 0, loc), s)], loc),
+                                                [((L'.PRecord [("1", (L'.PPrim (Prim.String ""), loc), s)], loc),
+                                                  (L'.ERel 0, loc)),
+                                                 ((L'.PRecord [("2", (L'.PPrim (Prim.String ""), loc), s)], loc),
+                                                  (L'.ERel 1, loc)),
+                                                 ((L'.PWild, loc),
+                                                  strcat [(L'.ERel 1, loc),
+                                                          (L'.EPrim (Prim.String ", "), loc),
+                                                          (L'.ERel 0, loc)])],
+                                                {disc = (L'.TRecord [("1", s), ("2", s)], loc),
+                                                 result = s}), loc)), loc)), loc),
                  fm)
             end
           | L.ECApp ((L.ECApp ((L.ECApp ((L.EFfi ("Basis", "sql_inner_join"), _), _), _), _), _), _) =>
@@ -2090,13 +2107,22 @@ fun monoExp (env, st, fm) (all as (e, loc)) =
                 ((L'.EAbs ("tab1", s, (L'.TFun (s, (L'.TFun (s, s), loc)), loc),
                            (L'.EAbs ("tab2", s, (L'.TFun (s, s), loc),
                                      (L'.EAbs ("on", s, s,
-                                               strcat [(L'.EPrim (Prim.String "("), loc),
-                                                       (L'.ERel 2, loc),
-                                                       (L'.EPrim (Prim.String " JOIN "), loc),
-                                                       (L'.ERel 1, loc),
-                                                       (L'.EPrim (Prim.String " ON "), loc),
-                                                       (L'.ERel 0, loc),
-                                                       (L'.EPrim (Prim.String ")"), loc)]), loc)), loc)), loc),
+                                               (L'.ECase ((L'.ERecord [("1", (L'.ERel 2, loc), s),
+                                                                       ("2", (L'.ERel 1, loc), s)], loc),
+                                                          [((L'.PRecord [("1", (L'.PPrim (Prim.String ""), loc), s)], loc),
+                                                            (L'.ERel 1, loc)),
+                                                           ((L'.PRecord [("2", (L'.PPrim (Prim.String ""), loc), s)], loc),
+                                                            (L'.ERel 2, loc)),
+                                                           ((L'.PWild, loc),
+                                                            strcat [(L'.EPrim (Prim.String "("), loc),
+                                                                    (L'.ERel 2, loc),
+                                                                    (L'.EPrim (Prim.String " JOIN "), loc),
+                                                                    (L'.ERel 1, loc),
+                                                                    (L'.EPrim (Prim.String " ON "), loc),
+                                                                    (L'.ERel 0, loc),
+                                                                    (L'.EPrim (Prim.String ")"), loc)])],
+                                                          {disc = (L'.TRecord [("1", s), ("2", s)], loc),
+                                                           result = s}), loc)), loc)), loc)), loc),
                  fm)
             end
           | L.ECApp ((L.ECApp ((L.ECApp ((L.EFfi ("Basis", "sql_left_join"), _), _), _), _), _),
@@ -2109,14 +2135,24 @@ fun monoExp (env, st, fm) (all as (e, loc)) =
                            (L'.EAbs ("tab1", s, (L'.TFun (s, (L'.TFun (s, s), loc)), loc),
                                      (L'.EAbs ("tab2", s, (L'.TFun (s, s), loc),
                                                (L'.EAbs ("on", s, s,
-                                                         strcat [(L'.EPrim (Prim.String "("), loc),
-                                                                 (L'.ERel 2, loc),
-                                                                 (L'.EPrim (Prim.String " LEFT JOIN "), loc),
-                                                                 (L'.ERel 1, loc),
-                                                                 (L'.EPrim (Prim.String " ON "), loc),
-                                                                 (L'.ERel 0, loc),
-                                                                 (L'.EPrim (Prim.String ")"), loc)]),
-                                                loc)), loc)), loc)), loc),
+                                                         (L'.ECase ((L'.ERecord [("1", (L'.ERel 2, loc), s),
+                                                                                 ("2", (L'.ERel 1, loc), s)], loc),
+                                                                    [((L'.PRecord [("1", (L'.PPrim (Prim.String ""),
+                                                                                          loc), s)], loc),
+                                                                      (L'.ERel 1, loc)),
+                                                                     ((L'.PRecord [("2", (L'.PPrim (Prim.String ""),
+                                                                                          loc), s)], loc),
+                                                                      (L'.ERel 2, loc)),
+                                                                     ((L'.PWild, loc),
+                                                                      strcat [(L'.EPrim (Prim.String "("), loc),
+                                                                              (L'.ERel 2, loc),
+                                                                              (L'.EPrim (Prim.String " LEFT JOIN "), loc),
+                                                                              (L'.ERel 1, loc),
+                                                                              (L'.EPrim (Prim.String " ON "), loc),
+                                                                              (L'.ERel 0, loc),
+                                                                              (L'.EPrim (Prim.String ")"), loc)])],
+                                                                    {disc = (L'.TRecord [("1", s), ("2", s)], loc),
+                                                                     result = s}), loc)), loc)), loc)), loc)), loc),
                  fm)
             end
           | L.ECApp ((L.ECApp ((L.ECApp ((L.EFfi ("Basis", "sql_right_join"), _), (L.CRecord (_, left), _)),
@@ -2129,14 +2165,24 @@ fun monoExp (env, st, fm) (all as (e, loc)) =
                            (L'.EAbs ("tab1", s, (L'.TFun (s, (L'.TFun (s, s), loc)), loc),
                                      (L'.EAbs ("tab2", s, (L'.TFun (s, s), loc),
                                                (L'.EAbs ("on", s, s,
-                                                         strcat [(L'.EPrim (Prim.String "("), loc),
-                                                                 (L'.ERel 2, loc),
-                                                                 (L'.EPrim (Prim.String " RIGHT JOIN "), loc),
-                                                                 (L'.ERel 1, loc),
-                                                                 (L'.EPrim (Prim.String " ON "), loc),
-                                                                 (L'.ERel 0, loc),
-                                                                 (L'.EPrim (Prim.String ")"), loc)]),
-                                                loc)), loc)), loc)), loc),
+                                                         (L'.ECase ((L'.ERecord [("1", (L'.ERel 2, loc), s),
+                                                                                 ("2", (L'.ERel 1, loc), s)], loc),
+                                                                    [((L'.PRecord [("1", (L'.PPrim (Prim.String ""),
+                                                                                          loc), s)], loc),
+                                                                      (L'.ERel 1, loc)),
+                                                                     ((L'.PRecord [("2", (L'.PPrim (Prim.String ""),
+                                                                                          loc), s)], loc),
+                                                                      (L'.ERel 2, loc)),
+                                                                     ((L'.PWild, loc),
+                                                                      strcat [(L'.EPrim (Prim.String "("), loc),
+                                                                              (L'.ERel 2, loc),
+                                                                              (L'.EPrim (Prim.String " RIGHT JOIN "), loc),
+                                                                              (L'.ERel 1, loc),
+                                                                              (L'.EPrim (Prim.String " ON "), loc),
+                                                                              (L'.ERel 0, loc),
+                                                                              (L'.EPrim (Prim.String ")"), loc)])],
+                                                                    {disc = (L'.TRecord [("1", s), ("2", s)], loc),
+                                                                     result = s}), loc)), loc)), loc)), loc)), loc),
                  fm)
             end
           | L.ECApp ((L.ECApp ((L.ECApp ((L.EFfi ("Basis", "sql_full_join"), _), (L.CRecord (_, left), _)), _),
@@ -2149,14 +2195,24 @@ fun monoExp (env, st, fm) (all as (e, loc)) =
                            (L'.EAbs ("tab1", s, (L'.TFun (s, (L'.TFun (s, s), loc)), loc),
                                      (L'.EAbs ("tab2", s, (L'.TFun (s, s), loc),
                                                (L'.EAbs ("on", s, s,
-                                                         strcat [(L'.EPrim (Prim.String "("), loc),
-                                                                 (L'.ERel 2, loc),
-                                                                 (L'.EPrim (Prim.String " FULL JOIN "), loc),
-                                                                 (L'.ERel 1, loc),
-                                                                 (L'.EPrim (Prim.String " ON "), loc),
-                                                                 (L'.ERel 0, loc),
-                                                                 (L'.EPrim (Prim.String ")"), loc)]),
-                                                loc)), loc)), loc)), loc),
+                                                         (L'.ECase ((L'.ERecord [("1", (L'.ERel 2, loc), s),
+                                                                                 ("2", (L'.ERel 1, loc), s)], loc),
+                                                                    [((L'.PRecord [("1", (L'.PPrim (Prim.String ""),
+                                                                                          loc), s)], loc),
+                                                                      (L'.ERel 1, loc)),
+                                                                     ((L'.PRecord [("2", (L'.PPrim (Prim.String ""),
+                                                                                          loc), s)], loc),
+                                                                      (L'.ERel 2, loc)),
+                                                                     ((L'.PWild, loc),
+                                                                      strcat [(L'.EPrim (Prim.String "("), loc),
+                                                                              (L'.ERel 2, loc),
+                                                                              (L'.EPrim (Prim.String " FULL JOIN "), loc),
+                                                                              (L'.ERel 1, loc),
+                                                                              (L'.EPrim (Prim.String " ON "), loc),
+                                                                              (L'.ERel 0, loc),
+                                                                              (L'.EPrim (Prim.String ")"), loc)])],
+                                                                    {disc = (L'.TRecord [("1", s), ("2", s)], loc),
+                                                                     result = s}), loc)), loc)), loc)), loc)), loc),
                  fm)
             end