(.module:
  lux
  (lux (control [monad #+ do]
                ["ex" exception #+ exception:])
       (data text/format
             (coll [list]))
       [macro]
       [host #+ do-to])
  (luxc ["&" lang]
        (lang [".L" host]
              (host ["$" jvm]
                    (jvm ["$t" type]
                         ["$d" def]
                         ["$i" inst]))
              ["la" analysis]
              ["ls" synthesis]))
  (// [".T" common]))

(exception: #export (Not-A-Tuple {message Text})
  message)

(def: $Object $.Type ($t.class "java.lang.Object" (list)))

(def: #export (translate-tuple translate members)
  (-> (-> ls.Synthesis (Meta $.Inst)) (List ls.Synthesis) (Meta $.Inst))
  (do macro.Monad<Meta>
    [#let [size (list.size members)]
     _ (&.assert Not-A-Tuple (%code (` [(~+ members)]))
                 (n/>= +2 size))
     membersI (|> members
                  list.enumerate
                  (monad.map @ (function (_ [idx member])
                                 (do @
                                   [memberI (translate member)]
                                   (wrap (|>> $i.DUP
                                              ($i.int (nat-to-int idx))
                                              memberI
                                              $i.AASTORE)))))
                  (:: @ map $i.fuse))]
    (wrap (|>> ($i.int (nat-to-int size))
               ($i.array $Object)
               membersI))))

(def: (flagI tail?)
  (-> Bool $.Inst)
  (if tail?
    ($i.string "")
    $i.NULL))

(def: #export (translate-variant translate tag tail? member)
  (-> (-> ls.Synthesis (Meta $.Inst)) Nat Bool ls.Synthesis (Meta $.Inst))
  (do macro.Monad<Meta>
    [memberI (translate member)]
    (wrap (|>> ($i.int (nat-to-int tag))
               (flagI tail?)
               memberI
               ($i.INVOKESTATIC hostL.runtime-class
                                "variant_make"
                                ($t.method (list $t.int $Object $Object)
                                           (#.Some ($t.array +1 $Object))
                                           (list))
                                false)))))