(;module:
  lux
  (lux (control monad)
       (data ["R" result]
             text/format)
       [macro #+ Monad<Lux> "Lux/" Monad<Lux>]
       [host #+ do-to])
  (luxc ["&" base]
        (lang ["la" analysis]
              ["ls" synthesis])
        ["&;" analyser]
        ["&;" synthesizer]
        (generator ["&;" common]
                   (host ["$" jvm]
                         (jvm ["$t" type]
                              ["$d" def]
                              ["$i" inst])))
        ))

(host;import java.lang.Object)
(host;import java.lang.String)

(host;import java.lang.reflect.Field
  (get [Object] Object))

(host;import (java.lang.Class a)
  (getField [String] Field))

(host;import org.objectweb.asm.Opcodes
  (#static ACC_PUBLIC int)
  (#static ACC_SUPER int)
  (#static ACC_FINAL int)
  (#static ACC_STATIC int)
  (#static PUTSTATIC int)
  (#static RETURN int)
  (#static V1_6 int)
  )

(host;import org.objectweb.asm.MethodVisitor
  (visitCode [] void)
  (visitEnd [] void)
  (visitLdcInsn [Object] void)
  (visitFieldInsn [int String String String] void)
  (visitInsn [int] void)
  (visitMaxs [int int] void))

(host;import org.objectweb.asm.FieldVisitor
  (visitEnd [] void))

(host;import org.objectweb.asm.ClassWriter
  (#static COMPUTE_MAXS int)
  (new [int])
  (visit [int int String String String (Array String)] void)
  (visitEnd [] void)
  (visitField [int String String String Object] FieldVisitor)
  (visitMethod [int String String String (Array String)] MethodVisitor)
  (toByteArray [] Byte-Array))

(def: eval-field Text "_value")
(def: $Object $;Type ($t;class "java.lang.Object" (list)))

(def: #export (eval generator)
  (-> (Lux $;Inst) (Lux Top))
  (do Monad<Lux>
    [class-name (:: @ map %code (macro;gensym "eval"))
     valueI generator
     #let [writer (|> (do-to (ClassWriter.new ClassWriter.COMPUTE_MAXS)
                        (ClassWriter.visit [&common;bytecode-version
                                            (i.+ Opcodes.ACC_PUBLIC Opcodes.ACC_SUPER)
                                            class-name
                                            (host;null)
                                            "java/lang/Object"
                                            (host;null)]))
                      ($d;field #$;Public {#$;staticF true #$;finalF true #$;transientF false #$;volatileF false}
                                eval-field $Object)
                      ($d;method #$;Public
                                 {#$;staticM true #$;finalM false #$;synchronizedM false}
                                 "<clinit>"
                                 ($t;method (list) #;None (list))
                                 (|>. valueI
                                      ($i;PUTSTATIC class-name eval-field $Object)
                                      $i;RETURN)))
           bytecode (ClassWriter.toByteArray [] (do-to writer (ClassWriter.visitEnd [])))]
     _ (&common;store-class class-name bytecode)
     class (&common;load-class class-name)]
    (wrap (|> class
              (Class.getField [eval-field])
              (Field.get (host;null))))))