;;; This processes type declarations (data, type, instance, class)
;;; Static errors in type declarations are detected and type decls
;;; are replaced by type definitions.  All code (class and instance
;;; definitions) is moved to the module decls.

(define *synonym-refs* '())

(predefine (add-derived-instances modules)) ; in derived/derived-instances.scm

(define (process-type-declarations modules)
;;; Convert data & type decls to definitions
 (let ((interface? (eq? (module-type (car modules)) 'interface)))
  (setf *synonym-refs* '())
  (walk-modules modules
   (lambda ()
     (setf (module-alg-defs *module*)
	   (map (function algdata->def) (module-algdatas *module*)))
     (setf (module-synonym-defs *module*)
	   (map (function synonym->def) (module-synonyms *module*)))
     (when (not interface?)
	(dolist (ty (default-decl-types (module-default *module*)))
		(resolve-type ty))))
   ;; A test to see that ty is in Num and is a monotype is needed here.
   )
  (multiple-value-bind (ty vals) (topsort *synonym-refs*)
    (when (eq? ty 'cyclic) (signal-recursive-synonyms vals)))
  ;; Build the class heirarchy
  (compute-super-classes modules)
  ;; Convert class declarations and instance declarations to definitions.
  (walk-modules modules
   (lambda ()
     (setf (module-class-defs *module*)
	   (map (function class->def) (module-classes *module*)))))
  (walk-modules modules
   (lambda ()
     (dolist (class (module-class-defs *module*))
	(setf (class-selectors class) (create-selector-functions class)))))
  (walk-modules modules
    (lambda ()
     (setf (module-instance-defs *module*) '())
     (dolist (inst-decl (module-instances *module*))
       (let ((inst (instance->def inst-decl)))
	 (when (not (eq? inst '#f))
            (push inst (module-instance-defs *module*)))))))
  (add-derived-instances modules)
  (walk-modules modules
   (lambda ()
     (dolist (inst (module-instance-defs *module*))
       (expand-instance-decls inst))))
  (when (not interface?)
   (walk-modules modules
    (lambda ()
     (dolist (ty (default-decl-types (module-default *module*)))
	(resolve-type ty)))))
   ))


(define (signal-recursive-synonyms vals)
  (fatal-error 'recursive-synonyms
    "There is a cycle in type synonym definitions involving these types:~%~a"
    vals))

(define (add-new-module-decl decl)
  (setf (module-decls *module*) (cons decl (module-decls *module*))))

(define (add-new-module-def var value)
  (add-new-module-decl
   (**define var '() value)))

(define (add-new-module-signature var signature)
  (add-new-module-decl
   (**signdecl/def (list var) signature)))