Support RETURN-FROM in DEF%TR forms

[maxima.git] / src / transl.lisp

;;; -*-  Mode: Lisp; Package: Maxima; Syntax: Common-Lisp; Base: 10 -*- ;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;     The data in this file contains enhancments.                    ;;;;;
;;;                                                                    ;;;;;
;;;  Copyright (c) 1984,1987 by William Schelter,University of Texas   ;;;;;
;;;     All rights reserved                                            ;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;     (c) Copyright 1980 Massachusetts Institute of Technology         ;;;
;;;                 GJC 9:29am  Saturday, 5 April 1980                   ;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(in-package :maxima)

(macsyma-module transl)

;;; File directory.

;;; TRANSL   Driver. Basic translation properties.
;;; TRANSS   User-interaction, FILE-I/O etc.
;;; TRANS1   Translation of JPG;MLISP and other FSUBRS.
;;;          which take call-by-name parameters.
;;; TRANS2   LISTS, ARRAYs, other random operators.
;;; TRANS3   LAMBDA. CLOSURES. also used by fsubr call-by-name
;;;          compatibility package.              
;;; TRANS4   operators, ".", "^^" some functions such as GAMMA.
;;; TRANS5   FSUBRS from COMM, and others, these are mere MACRO
;;;          FSUBRS.
;;; TRANSF   floating point intensive properties. BIGFLOAT stuff.
;;; TROPER   Basic OPERATORS.
;;; TRUTIL   transl utilities.
;;; TRMODE   definition of MODEDECLARE. run time error checking code.
;;; TRDATA   this is the MODE data for the "built-in" functions.
;;; TRANSM   This defines the macro DEF%TR. When compiled on MC
;;;          DEF%TR produces autoload definitions for TRANS1 thru L.
;;; PROCS    macro's needed.
;;; TRANSQ   these are macros for translated code. Loaded by TPRELU
;;;          this is compile-time only.
;;; MDEFUN   contains the macro which defines macsyma functions.
;;;          runtime and compile-time.
;;; ACALL    is some run time support for translated code, array calls.
;;; FCALL    run-time translated function call support for uncompiled
;;;          code. Many FSUBRS which are macros in TRANSQ.
;;; EVALW    EVAL-WHEN definition for interpreter.
;;; MLOAD    This has a hack hook into BATCH, which is needed to do
;;;          TRANSLATE_FILE I/O. when using old-i/o SUPRV.


;;; Functions and literals have various MODE properties;;; >
;;; (at user level set up by $MODEDECLARE), such as "$FLOAT" and "$ANY".
;;; The main problem solved by this translator (and the reason that
;;; it works on forms from the "inside out" as an evaluator would do
;;; (expect for macro forms)), is the problem of type (MODE) dependent
;;; function calling and mode conversion. The function TRANSLATE
;;; returns a list  where the CAR of the list is the MODE of the
;;; expression and the CDR is the expression to be evaluated by
;;; the lisp evaluator to give the equivalent result of evaluating
;;; the given macsyma expression with the macsyma evaluator.
;;; One doesn't know the MODE of an expression until seeing the modes
;;; of all its parts. See "*UNION-MODE"

;;; weak points in the code
;;; [1] duplication of functionality in the translators for
;;; MPLUS MTIMES etc. 
;;; [3] primitive mode scheme. lack of even the most primitive general
;;; type coercion code. Most FORTRAN compilers are better than this.
;;; [4] for a compiler, this code SUCKS when it comes to error checking
;;; of the code it is munging. It doesn't even do a WNA check of system
;;; functions!
;;; [5]
;;; The duplication of the code which handles lambda binding, in MDO, MDOIN
;;; TR-LAMBDA, and MPROG, is very stupid. For macsyma this is one of
;;; the hairier things. Declarations must be handled, ASSIGN properties...
;;; -> Binding of ASSIGN properties should be handled with he "new"
;;; UNWIND-PROTECT instead of at each RETURN, and at "hope" points such as
;;; the ERRLIST. {Why wasn't this obvious need for UNWIND-PROTECT made
;;; known to the lisp implementers by the macsyma implementers? Why did it
;;; have to wait for the lisp machine group? Isn't this just a generalization
;;; of special binding?}
;;; [6] the DCONVX idea here is obscurely coded, incomplete, and totally
;;; undocumented. It was probably an attempt to hack efficient
;;; internal representations (internal to a given function), for some macsyma
;;; data constructs, and yet still be sure that fully general legal data
;;; frobs are seen outside of the functions. Note: this can be done
;;; simply by type coercion and operator folding.

;;; General comments on the structure of the code.
;;; A function named TR-<something> means that it translates
;;; something having to do with that something.
;;; N.B. It does not mean that that is the translate property for <something>.


(defvar *untranslated-functions-called* nil)

(defmvar *declared-translated-functions* nil
         "List of functions which are believed to be translated.")

(defmvar tstack nil " stack of local variable modes ")

(defmvar local nil "T if a $local statement is in the body.")
(defmvar tr-progret t)
(defmvar inside-mprog nil)
(defmvar returns nil "list of `translate'd return forms in the block.")
(defmvar return-mode nil "the highest(?) mode of all the returns.")
(defmvar need-prog? nil)
(defmvar assigns nil "These are very-special variables which have a Maxima
        assign property which must be called to bind and unbind the variable
        whenever it is `lambda' bound.")

(defmvar translate-time-evalables
    '($modedeclare $alias $declare $infix $nofix $declare_translated
      $matchfix $prefix $postfix $compfile))

(defmvar *transl-backtrace* nil
  " What do you think? ")

(defmvar *transl-debug* nil "if T it pushes `backtrace' and `trace' ")

(defmvar tr-abort nil "set to T if abortion is requested by any of the
        sub-parts of the translation. A *THROW would be better, although it
        wouldn't cause the rest of the translation to continue, which may
        be useful in translation for MAXIMA-ERROR checking.")

(defmvar tr-unique (gensym)
  "this is just a unque object used for random purposes,
        such as the second (file end) argument of READ.")


(defmvar $tr_warn_undeclared '$compile
  "When to send warnings about undeclared variables to the TTY")

(defmvar $tr_warn_meval '$compfile
  "If `meval' is called that indicates problems in the translation")

(defmvar $tr_warn_fexpr
    '$compfile
  "FEXPRS should not normally be output in translated code, all legitimate
special program forms are translated.")

(defmvar $tr_warn_mode '$all
  "Warn when variables are assigned values out of their mode.")

(defmvar $tr_warn_undefined_variable '$all
  "Warn when undefined global variables are seen.")


(defmvar *warned-un-declared-vars* nil "Warning State variable")
(defmvar *warned-fexprs* nil "Warning State variable")
(defmvar *warned-mode-vars* nil "Warning State variable")

(defmvar $tr_function_call_default '$general
  "
FALSE means punt to MEVAL, EXPR means assume lisp fixed arg function.
GENERAL, the default gives code good for mexprs and mlexprs but not macros.
GENERAL assures variable bindings are correct in compiled code.
In GENERAL mode, when translating F(X), if F is a bound variable, then
it assumes that APPLY(F,[X]) is meant, and translates a such, with 
appropriate warning. There is no need to turn this off.
APPLY means like APPLY.")

(defmvar $tr_array_as_ref t
  "If true runtime code uses value of the variable as the array.")

(defmvar $tr_numer nil
  "If `true' numer properties are used for atoms which have them, e.g. %pi")

(defvar boolean-object-table
  '(($true . ($boolean . t))
    ($false . ($boolean . nil))
    (t . ($boolean . t))
    (nil . ($boolean . nil))))

(defvar mode-init-value-table
  '(($float . 0.0)
    ($fixnum . 0)
    ($number  . 0)
    ($list . '((mlist)))
    ($boolean  . nil)))

(defvar tr-lambda-punt-assigns nil
  "Kludge argument to `tr-lambda' due to lack of keyword argument passing")

(or (boundp '*in-compile*)
    (setq *in-compile* nil))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;


(defun barfo (msg)
  (tr-format (intl:gettext "Internal translator error: ~M~%") msg)
  (cond (*transl-debug*
         (break "transl barfo"))
        (t
         (setq tr-abort t)
         nil)))

(defun specialp (var)
  (or (optionp var)
      (tr-get-special var)))


;;; The error message system. Crude as it is.
;;; I tell you how this aught to work:
;;; (1) All state should be in one structure, one state variable.
;;; (2) Should print out short message on-the-fly so that it
;;;     gives something to watch, and also so that it says something
;;;     if things crash.
;;; (3) Summaries on a cross-referenced per-function and per-item
;;;     should be printed at the end, as a table.
;;;     e.g.
;;;     Undefined Functions     used in
;;;     FOO                     BAR, BAZ,BOMB
;;;     FOOA                    P,Q
;;;     Undefined Variables ... same thing
;;;     Incomprehensible special forms
;;;     EV                      ....
;;;     Predicate Mode Targeting failures.
;;;     .....  -gjc

;;; The way it works now is to print too little or too much.
;;; Many items are only warned about the first time seen.
;;; However, this isn't too much of a problem when using Emacs
;;; to edit code, because searching for warned-about tokens
;;; is quick and easy.

(defmvar *tr-warn-break* t
  " if in debug mode `warning's signaled go to lisp break loops ")

(defmacro tr-warnbreak ()
  `(and *transl-debug* *tr-warn-break* (break "transl")))

(defun tr-warnp (val)
  (and val
       (cond (*in-compile*
              (member val '($all $compile $compfile $translate) :test #'eq))
             ((or *in-compfile* *in-translate-file*)
              (member val '($all $compfile $translate) :test #'eq))
             (*in-translate*
              (member val '($all $translate) :test #'eq)))))

(defvar warned-undefined-variables nil)

(defun warn-undefined-variable (form)
  (and (tr-warnp $tr_warn_undefined_variable)
       (cond ((member form warned-undefined-variables :test #'eq))
             (t
              (push form warned-undefined-variables)
              (tr-format (intl:gettext "warning: encountered undefined variable ~:M in translation.~%") form)
              (tr-warnbreak)))))

(defun warn-undeclared (form &optional comment)
  (and (tr-warnp $tr_warn_undeclared)
       (cond ((member form *warned-un-declared-vars* :test #'equal) t)
             (t
              (push form *warned-un-declared-vars*)
              (tr-format (intl:gettext "warning: no type declaration for ~:M; assume type is 'any'.~%") form)
              (tr-format (intl:gettext "note: 'modedeclare' declares types for translation.~%"))
              (cond (comment
                     (dolist (v *translation-msgs-files*)
                       (terpri v)
                       (princ comment v))))
              (tr-warnbreak)
              nil))))

(defun warn-meval (form &optional comment)
  (cond ((tr-warnp $tr_warn_meval)
         (tr-format (intl:gettext "warning: emit call to MEVAL for expression: ~:M~%") form)
         (cond (comment (dolist (v *translation-msgs-files*)
                          (terpri v)
                          (princ comment v))))
         (tr-warnbreak)
         'warned)))


(defun warn-mode (var mode newmode &optional comment)
  (cond ((eq mode newmode))
        (t
         (cond ((and (tr-warnp $tr_warn_mode)
                     (not (covers mode newmode))
                     (not (member (list var mode newmode) *warned-mode-vars* :test #'equal)))
                (push (list var mode newmode) *warned-mode-vars*)
                (tr-format (intl:gettext "warning: variable ~:M (declared type ~:M) assigned type ~:M.~%") var mode newmode)
                (cond (comment
                       (dolist (v *translation-msgs-files*)
                         (terpri v)
                         (princ comment v))))
                (tr-warnbreak))))))

(defun warn-fexpr (form &optional comment)
  (cond ((and (tr-warnp $tr_warn_fexpr)
              (not (member form *warned-fexprs* :test #'equal)))
         (push  form *warned-fexprs*)
         (tr-format (intl:gettext "warning: ~:M is a special function without a full Lisp translation.~%") form)
         (tr-format (intl:gettext "warning: calling ~:M in compiled code might not have the desired effect.~%") form)
         (cond (comment
                (dolist (v *translation-msgs-files*)
                  (terpri v)
                  (princ comment v))))
         (tr-warnbreak))))


(defun macsyma-special-macro-p (fcn)
  (getl-lm-fcn-prop fcn '(macro)))

(defun macsyma-special-op-p (f)
  (getl f '(fsubr fexpr mfexpr* mfexpr*s *fexpr)))

(defun possible-predicate-op-p (f)
  (member f '(mnotequal mequal $equal mgreaterp mgeqp mlessp mleqp) :test #'eq))

;;;***************************************************************;;;

;;; This function is the way to call the TRANSLATOR on an expression with
;;; locally bound internal mode declarations. Result of TR-LAMBDA will be
;;; (MODE . (LAMBDA (...) (DECLARE ...) TRANSLATED-EXP))

(defun tr-local-exp (exp &rest vars-modes)
  (let ((loc (let ((tr-lambda-punt-assigns t))
               (tr-lambda `((lambda) ((mlist) ,@(do ((l vars-modes (cddr l))
                                                     (ll nil (cons (car l) ll)))
                                                    ((null l) ll)
                                                    (or (variable-p (car l))
                                                        (bad-var-warn (car l)))))
                            (($modedeclare) ,@vars-modes)
                            ,exp)))))
    (let ((mode (car loc))
          (exp (car (last loc))))
      (cons mode exp))))

(defun tr-args (form)
  (mapcar #'(lambda (x) (dconvx (translate x))) form))

(defun dtranslate (form) (cdr (translate form)))

(defun dconv (x mode) 
  (cond ((eq '$float mode) (dconv-$float x))
        ((eq '$cre mode) (dconv-$cre x))
        (t (cdr x))))

(defun dconvx (x) 
  (if (member (car x) '(ratexpr pexpr) :test #'eq)
      (dconv-$cre x)
      (cdr x)))

(defun dconv-$float (x)
  (cond ((member (car x) '($fixnum $number) :test #'eq)
         (if (integerp (cdr x)) (float (cdr x)) (list 'float (cdr x))))
        ((eq '$rational (car x))
         (cond ((or (atom (cdr x))
                    (not (eq 'quote (cadr x))))
                `($float ,(cdr x)))
               (t
                (/ (float (cadadr (cdr x))) (float (caddr (caddr x)))))))
        (t (cdr x))))

(defun dconv-$cre (x)
  (if (eq '$cre (car x))
      (cdr x)
      `(ratf ,(cdr x))))

(defmvar *$any-modes* '($any $list))

(defun covers (mode1 mode2)
  (cond ((eq mode1 mode2) t)
        ((eq '$float mode1) (member mode2 '($float $fixnum $rational) :test #'eq))
        ((eq '$number mode1) (member mode2 '($fixnum $float) :test #'eq))
        ((member mode1 *$any-modes* :test #'eq) t)))

;;; takes a function name as input.

(defun tr-mfun (name &aux (*transl-backtrace* nil))
  (let ((def-form (consfundef name nil nil)))
    (cond ((null def-form)
           (setq tr-abort t))
          (t
           (tr-mdefine-toplevel def-form)))))

;;; DEFUN
;;; All the hair here to deal with macsyma fexprs has been flushed.
;;; Right now this handles MDEFMACRO and MDEFINE. The decisions
;;; of where to put the actual properties and what kind of
;;; defuns to make (LEXPR EXPR for maclisp) are punted to the
;;; macro package.

(defun tr-mdefine-toplevel (form &aux (and-restp nil))
  (destructuring-let (((((name . flags) . args) body) (cdr form))
                      (a-args) kind out-forms)

    (do ((args args (cdr args))
         ;; array functions cannot be LEXPR-like. gee.
         ;; there is no good reason for that, except for efficiency,
         ;; and I know that efficiency was not a consideration.
         (full-restricted-flag (or (eq name 'mqapply)
                                   (member 'array flags :test #'eq))))
        ((null args) (setq a-args (nreverse a-args)))
      (let ((u (car args)))
        (cond ((atom u)
               (push u a-args))
              ((and (not full-restricted-flag)
                    (not and-restp)
                    (eq (caar u) 'mlist)
                    (cdr u) (atom (cadr u)))
               (push (cadr u) a-args)
               (setq and-restp t))
              (t
               (push tr-unique a-args)))))

    
    (cond ((eq name 'mqapply) 
           ;; don't you love syntax!
           ;; do a switch-a-roo here. Calling ourselves recursively
           ;; like this allows all legal forms and also catches
           ;; errors. However, certain generalizations are also
           ;; allowed. They won't get passed the interpreter, but
           ;; interesting things may happen here. Thats what you
           ;; get from too much syntax, so don't sweat it.
           (tr-mdefine-toplevel
            `(,(car form) ,(car args)
              ((lambda) ((mlist) ,@(cdr args)) ,body))))
          ((member tr-unique a-args :test #'eq)
           ;; WHAT IS "BAD" ABOUT THE ARGUMENT LIST HERE ??
           (tr-format (intl:gettext "error: unhandled argument list in function definition: ~:M~%") `((mlist),@args))
           (setq tr-abort t)
           nil)
          ((member (caar form) '(mdefine mdefmacro) :test #'eq)
           (setq kind (cond ((eq (caar form) 'mdefmacro) 'macro)
                            ((member 'array flags :test #'eq) 'array)
                            (t 'func)))
           (let* ((t-form
                   (tr-lambda `((lambda) ((mlist) ,@a-args) ,body)))
                  (desc-header
                   `(,name ,(car t-form) ,(caar form)
                     ,and-restp ,(eq kind 'array))))
             (cond ((eq kind 'func)
                    (push-pre-transl-form
                     `(defmtrfun-external ,desc-header))
                    (and (not (member (car t-form) '($any nil) :test #'eq))
                         (putprop name (car t-form) 'function-mode)))
                   ((eq kind 'array)
                    (and (not (member (car t-form) '($any nil) :test #'eq))
                         (decmode-arrayfun name (car t-form)))))

             (cond ((or *in-translate* (not $packagefile))
                                        ; These are all properties which tell the
                                        ; user that functions are in the environment,
                                        ; and that also allow him to SAVE the functions.
                    (push `(defprop ,name t translated) out-forms)
                    (push `(add2lnc ',name $props) out-forms)
                    (cond ((eq '$all $savedef)
                           (push
                            `(add2lnc
                              '((,name ,@flags) ,@args)
                              ,(case kind
                                     (array '$arrays)
                                     (func '$functions)
                                     (macro '$macros))) out-forms)))))
             (cond ((eq '$all $savedef)
                    ;; For some reason one may want to save the
                    ;; interpreted definition even if in a PACKAGEFILE.
                    ;; not a good idea to use SAVEDEF anyway though.
                    (push `(mdefprop ,name
                            ((lambda) ((mlist) ,@args) ,body)
                            ,(case kind
                                   (array 'aexpr)
                                   (macro 'mmacro)
                                   (func 'mexpr)))
                          out-forms)))
             ;;once a function has been translated we want to make sure mfunction-call is eliminated.
             (progn
               (remprop (car desc-header) 'undefined-warnp)
               (setf (get (car desc-header) 'once-translated) "I was once translated"))
             `(progn
                ,@(nreverse out-forms)
                (defmtrfun ,desc-header ,@(cdr (cdr t-form))))))
          (t
           (barfo '?)))))

(defun translate-function (name)
  (bind-transl-state
   (setq *in-translate* t)
   (let ((lisp-def-form (tr-mfun name))
         (delete-subr? (and (get name 'translated)
                            (not (get name 'expr)))))
     (cond (tr-abort
            (trfail name))
           (t
            (if delete-subr? (remprop name 'subr))
            (if (mget name 'trace) (macsyma-untrace name))
            (if (not $savedef) (meval `(($remfunction) ,name)))
            (let ((lisp-action
                                        ; apply EVAL so it is easy to TRACE.
                                        ; ERRSET is crude, but...
                   (errset (apply 'eval (list lisp-def-form)))))
              (cond ((not lisp-action)
                     (trfail name))
                    (t name))))))))

(defun punt-to-meval (form &optional (mode '$any))
  (cons mode `(meval ',form)))

(defun trfail (x)
  (tr-format (intl:gettext "error: failed to translate ~:@M~%") x)
  nil)

(defun translate-and-eval-macsyma-expression (form)
  ;; this is the hyper-random entry to the transl package!
  ;; it is used by MLISP for TRANSLATE:TRUE "::=".
  (bind-transl-state
   (setq *in-translate* t)
   ;; Use TRANSLATOR-EVAL so we don't have to lose badly by tracing EVAL
   (translator-eval (translate-macexpr-toplevel form))))

(defun translator-eval (x)
  (eval x))

;; This basically tells the msetq def%tr to use defparameter insetad
;; of setq because we're doing a setq at top-level, which isn't
;; specified by ANSI CL.
(defvar *macexpr-top-level-form-p* nil)

(defun translate-macexpr-toplevel (form &aux (*transl-backtrace* nil) tr-abort)
  ;; there are very few top-level special cases, I don't
  ;; think it would help the code any to generalize TRANSLATE
  ;; to target levels.
  ;;
  ;; Except msetq at top-level is special for ANSI CL.  See below.
  (setq form (toplevel-optimize form))
  (cond ((atom form) nil)
        ((eq (caar form) '$eval_when)
         (let ((whens (cadr form))
               (body (cddr form)) tr-whens)
           (setq whens (cond (($listp whens) (cdr whens))
                             ((atom whens) (list whens))
                             (t
                              (tr-format (intl:gettext "error: 'eval_when' argument must be a list or atom; found: ~:M~%") (cadr form))
                              nil)))
           (setq tr-whens (mapcar 'stripdollar whens))
           (cond ((member '$translate whens :test #'eq)
                  (mapc 'meval body)))
           (cond ((member '$loadfile whens :test #'eq)
                  `(progn
                     ,@(mapcar 'translate-macexpr-toplevel body)))
                 ((setq tr-whens (intersect tr-whens '(:compile-toplevel :load-toplevel :execute)))
                  `(eval-when
                       ,tr-whens
                     ,@(mapcar 'translate-macexpr-toplevel body)))
                 ((member '$compile whens :test #'eq)
                  ;; strictly for the knowledgeable user.
                  `(eval-when
                       #+gcl (compile)
                       #-gcl (:compile-toplevel)
                       ,@(mapcar 'translate-macexpr-toplevel body))))))
        ((member (caar form) translate-time-evalables :test #'eq)
         (meval1 form)
         `(eval-when
              #+gcl (compile load eval)
              #-gcl (:compile-toplevel :load-toplevel :execute)
              (meval* ',form)))
        ((member  (caar form) '(mdefine mdefmacro) :test #'eq)
         (let ((name (caaadr form))
               (trl))
           (tr-format (intl:gettext "note: translating ~:@M~%") name)
           (setq trl (tr-mdefine-toplevel form))
           (cond (tr-abort
                  (tr-format (intl:gettext "error: failed to translate ~:@M~%") name)
                  (tr-format (intl:gettext "note: keep going and hope for the best.~%"))
                  `(meval* ',form))
                 (t trl))))
        ((eq 'mprogn (caar form))
         ;; note that this ignores the $%% crock.
         `(progn ,@(mapcar #'translate-macexpr-toplevel (cdr form))))
        ((eq 'msetq (caar form))
         ;; Toplevel msetq's should really be defparameter instead of
         ;; setq for Common Lisp.  
         (let ((*macexpr-top-level-form-p* t))
           (dtranslate form)))
        ((eq '$define_variable (caar form))
         ;; Toplevel msetq's should really be defparameter instead of
         ;; setq for Common Lisp.  
         (let ((*macexpr-top-level-form-p* t))
           (dtranslate form)))
        (t              
         (let  ((t-form (dtranslate form)))
           (cond (tr-abort
                  `(meval* ',form))
                 (t
                  t-form))))))



(defmvar $tr_optimize_max_loop 100.
  "The maximum number of times the macro-expansion and optimization
         pass of the translator will loop in considering a form.
         This is to catch macro expansion errors, and non-terminating
         optimization properties.")

(defun toplevel-optimize (form)
  ;; it is vital that optimizations be done within the
  ;; context of variable meta bindings, declarations, etc.
  ;; Also: think about calling the simplifier here.
  (cond ((atom form)
         (cond ((symbolp form)
                ;; If this symbol has the constant property, then
                ;; use its assigned constant value in place of the
                ;; symbol.
                (let ((v (getl (mget form '$props) '($constant))))
                  (if v (cadr v) form)))
               (t form)))
        (t
         (do ((new-form)
              (kount 0 (1+ kount)))
             ;; tailrecursion should always arrange for a counter
             ;; to check for mobylossage.
             ((> kount $tr_optimize_max_loop)
              (tr-format (intl:gettext "warning: I've looped ~A times in macro expansion; just give up and return ~:@M~%")
               $tr_optimize_max_loop (caar form))
              form)
           (setq new-form (toplevel-optimize-1 form))
           (cond ((atom new-form)
                  (return (toplevel-optimize new-form)))
                 ((eq new-form form)
                  (return form))
                 (t
                  (setq form new-form)))))))

(defun toplevel-optimize-1 (form &aux (op (car form)) prop)
  (cond ((or (atom op)
             (member 'array op :test #'eq)) form)
        ((progn (setq op (car op))
                (setq prop
                      (if $transrun     ; crock a minute.
                          (or (get op 'translated-mmacro)
                              (mget op 'mmacro))
                          (or (mget op 'mmacro)
                              (get op 'translated-mmacro)))))
         (mmacro-apply prop form))
        ((setq prop ($get op '$optimize))
         ;; interesting, the MAPPLY here causes the simplification
         ;; of the form and the result.
         ;; The optimize property can be used to implement
         ;; such niceties as the $%% crock.
         (mapply1 prop (list form) "an optimizer property" nil))
        ((and ($get op '$transload)
              (get op 'autoload)
              ;; check for all reasonable definitions,
              ;; $OPTIMIZE and MACRO already checked.
              (not (or (get-lisp-fun-type op)
                       (getl op '(translate mfexpr* mfexpr*s
                                  fsubr fexpr *fexpr
                                  macro
                                  ;; foobar?
                                  ))
                       (mgetl op '(mexpr)))))
         (load-function op t)
         ;; to loop.
         (cons (car form) (cdr form)))
        (t form)))

(defun translate (form)
  (and *transl-debug* (push form *transl-backtrace*))
  (setq form (toplevel-optimize form))
  (and *transl-debug* (pop *transl-backtrace*))
  (prog2
      (and *transl-debug* (push form *transl-backtrace*))
      (if (atom form)
          (translate-atom form)
          (translate-form form))
    ;; hey boy, reclaim that cons, just don't pop it!
    (and *transl-debug* (pop *transl-backtrace*))))

(defun translate-atom (form &aux temp)
  (cond ((numberp form) (cons (tr-class form) form))
        ((setq temp (assoc form boolean-object-table :test #'eq))
         (cdr temp))
        ((and (setq temp (mget form '$numer)) $tr_numer)
         `($float . ,temp))
        ((implied-quotep form)
         `($any . ',form))
        ((self-evaluating-lisp-object-p form)
         `($any . ,form))
        ((tboundp form)
         (setq form (teval form))
         `(,(value-mode form) . ,form))
        (t
         (cond ((not (specialp form))
                (warn-undefined-variable form)))
         ;; note that the lisp analysis code must know that
         ;; the TRD-MSYMEVAL form is a semantic variable.
         (let* ((mode (value-mode form))                
                (init-val (assoc mode mode-init-value-table :test #'eq)))
           (setq init-val (cond (init-val (cdr init-val))
                                (t `',form)))
           ;; in the compiler TRD-MSYMEVAL doesn't do a darn
           ;; thing, but it provides dynamic initialization of
           ;; variables in interpreted code which is translated
           ;; in-core. In FILE loaded code the DEFVAR will take
           ;; care of this.
           (push-defvar form init-val)
           `(,mode . (trd-msymeval ,form ,init-val))))))

(defun translate-form (form &aux temp)
  (cond ((eq (car form) 'meval) (cons '$any form)) ;;for those lispy macsyma forms
        ((not (atom (caar form)))
         ;; this is a check like that in the simplifier. form could
         ;; result from substitution macros.
         (translate `((mqapply) ,(caar form) . ,(cdr form))))
        ((member 'array (cdar form) :test #'eq)
         ;; dispatch this bad-boy to another module quick.
         (tr-arraycall form))
        ;; TRANSLATE properties have priority.
        ((setq temp (get (caar form) 'translate))
         (funcall temp form))
        ((setq temp (get-lisp-fun-type (caar form)))
         (tr-lisp-function-call form temp))
        ((macsyma-special-macro-p (caar form))
         (attempt-translate-random-macro-op form))
        ((macsyma-special-op-p (caar form))
         ;; a special form not handled yet! foobar!
         (attempt-translate-random-special-op form))
        ((or (get (caar form) 'noun) (get (caar form) 'operators))
         ;; puntastical case. the weird ones are presumably taken care
         ;; of by TRANSLATE properties by now.
         (tr-infamous-noun-form form))

        ;; "What does a macsyma function call mean?".
        ;; By the way, (A:'B,B:'C,C:'D)$ A(3) => D(3)
        ;; is not supported.
        (t
         (tr-macsyma-user-function-call (caar form) (cdr form) form))))



(defmvar $tr_bound_function_applyp t)

(defun tr-macsyma-user-function-call (function args form)
  ;; this needs some work, output load-time code to
  ;; check for MMACRO properties, etc, to be really
  ;; foolproof.
  (cond ((eq $tr_function_call_default '$apply)
         (translate `(($apply) ,(caar form) ((mlist) ,@(cdr form)))))
        ((eq $tr_function_call_default '$expr)
         (tr-lisp-function-call form 'subr))
        ((eq $tr_function_call_default '$general)
         (cond 
             ;;; G(F,X):=F(X+1); case.
           ((and $tr_bound_function_applyp (tboundp function))
            (let ((new-form `(($apply) ,function ((mlist) ,@args))))
              (tr-format (intl:gettext "warning: ~:M is a bound variable in ~:M, but it is used as a function.~%") function form)
              (tr-format (intl:gettext "note: instead I'll translate it as: ~:M~%") new-form)
              (translate new-form)))
           ;; MFUNCTION-CALL cleverely punts this question to a FSUBR in the
           ;; interpreter, and a macro in the compiler. This is good style,
           ;; if a user is compiling then assume he is less lossage prone.
           (t
            (pushnew (caar form) *untranslated-functions-called*)
              (call-and-simp
               (function-mode (caar form))
               'mfunction-call `(,(caar form) ,@(tr-args args))))))
        (t
         ;; This case used to be the most common, a real loser.
         (warn-meval form)
         (punt-to-meval form (function-mode (caar form))))))


(defun attempt-translate-random-macro-op (form)
  (warn-fexpr form)
  `($any . ,(cons (caar form) (cdr form))))

(defun attempt-translate-random-special-op (form)
  (warn-fexpr form)
  (punt-to-meval form (function-mode (caar form))))


(defun tr-lisp-function-call (form type)
  (let ((op (caar form)) (mode) (args))
    (setq args (cond ((member type '(subr lsubr expr) :test #'eq)
                      (mapcar #'(lambda (llis) (dconvx (translate llis)))
                              (cdr form)))
                     (t
                      (mapcar 'dtranslate (cdr form))))
          mode (function-mode op))
    (call-and-simp mode op args)))

;;the once-translated is so that inside translate file where a function
;;has been translated, subsequent calls won't use mfunction call
(defun get-lisp-fun-type (fun &aux temp)
  ;; N.B. this is Functional types. NOT special-forms,
  ;; lisp special forms are meaningless to macsyma.
  (cond ((get fun '*lexpr) 'lsubr)
        ((get fun '*expr) 'subr)
        ;; *LEXPR & *EXPR gotten from DEFMFUN declarations
        ;; which is loaded by TrData.
        ((mget fun '$fixed_num_args_function)
         'subr)
        ((mget fun '$variable_num_args_function)
         'lsubr)
        ((setq temp (getl fun '(expr subr lsubr)))
         (car temp))
        ((get fun 'once-translated))
        ((get fun 'translated))
        (t nil)))

(defun tr-infamous-noun-form (form)
  ;; 'F(X,Y) means noun-form. The arguments are evaluated.
  ;;  but the function is cons on, not applied.
  ;;  N.B. for special forms and macros this is totally wrong.
  ;;  But, those cases are filtered out already, presumably.
       
  (let ((op (cond ((member 'array (car form) :test #'eq)
                   `(,(caar form) array))
                  (t `(,(caar form)))))
        (args (tr-args (cdr form))))
    `($any . (simplify (list ',op ,@args)))))

;;; Some atoms, solely by usage, are self evaluating. 
(defun implied-quotep (x)
  (safe-get x 'implied-quotep))

(defun self-evaluating-lisp-object-p (x)
  (not (or (symbolp x) (consp x))))

;;; the Translation Properties. the heart of TRANSL.

;;; This conses up the call to the function, adding in the
;;; SIMPLIFY i the mode is $ANY. This should be called everywhere.
;;; instead of duplicating the COND everywhere, as is done now in TRANSL.

(defun tr-nosimpp (op)
  (cond ((atom op)
         (get op 'tr-nosimp))
        (t nil)))

(defun call-and-simp (mode fun args)
  (cond ((or (not (eq mode '$any))
             (tr-nosimpp fun))
         `(,mode ,fun . ,args))
        (t
         `(,mode simplify (,fun . ,args)))))

(defmspec $declare_translated (fns)
  (setq fns (cdr fns))
  (loop for v in fns
        when (or (symbolp v) (and (stringp v) (setq v ($verbify v))))
        do (setf (get v 'once-translated) t)
        (pushnew v *declared-translated-functions*)
        else do (merror (intl:gettext "declare_translated: arguments must be symbols or strings; found: ~:M") v)))

(def%tr $eval_when (form)
  (tr-format (intl:gettext "error: found 'eval_when' in a function or expression: ~:M~%") form)
  (tr-format (intl:gettext "note: 'eval_when' can appear only at the top level in a file.~%"))
  (setq tr-abort t)
  '($any . nil))

(def%tr mdefmacro (form)
  (tr-format (intl:gettext "warning: globally defining macro ~:M now to ensure correct macro expansions.~%") (caaadr form))
  ; Define the macro now to ensure that it's defined when it's time
  ; to expand it.  It's a bug that this definition occurs during
  ; translation without being cleaned it up afterward, but simply
  ; removing this breaks things.
  (meval form)
  (punt-to-meval form))

(def%tr $local (form)
  (when local
    (tr-format (intl:gettext "error: there is already a 'local' in this block.~%"))
    (setq tr-abort t)
    (return-from $local nil))
  (setq local t)
  ; We can't just translate to a call to MLOCAL here (which is
  ; what used to happen).  That would push onto LOCLIST and bind
  ; MLOCP at the "wrong time".  The push onto LOCLIST and the
  ; binding of MLOCP are handled in TR-LAMBDA.
  (punt-to-meval form))


(def%tr mquote (form)
  (list (tr-class (cadr form)) 'quote (cadr form)))


(defun tr-lambda (form &optional (tr-body #'tr-seq) &rest tr-body-argl
                  &aux
                  (arglist (mparams (cadr form)))
                  (easy-assigns nil)
                  (local nil))
  ;; This function is defined to take a simple macsyma lambda expression and
  ;; return a simple lisp lambda expression. The optional TR-BODY hook
  ;; can be used for translating other special forms that do lambda binding.
  
  ;; Local SPECIAL declarations are not used because
  ;; the multics lisp compiler does not support them. They are of course
  ;; a purely syntactic construct that doesn't buy much. I have been
  ;; advocating the use of DEFINE_VARIABLE in macsyma user programs so
  ;; that the use of DECLARE(FOO,SPECIAL) will be phased out at that level.

  (mapc #'tbind arglist)
  (destructuring-let* (((mode . nbody) (apply tr-body (cddr form) tr-body-argl))
                       (local-declares (make-declares arglist t))
                       (body (if local
                                 `((let ((mlocp t))
                                     (push nil loclist)
                                     (unwind-protect
                                         (progn ,@nbody)
                                       (munlocal))))
                                 nbody)))
    ;; -> BINDING of variables with ASSIGN properties may be difficult to
    ;; do correctly and efficiently if arbitrary code is to be run.
    (if (or tr-lambda-punt-assigns
            (do ((l arglist (cdr l)))
                ((null l) t)
              (let* ((var (car l))
                     (assign (get var 'assign)))
                (if assign
                    (cond ((eq assign 'assign-mode-check)
                           (push `(,assign ',var ,(teval var)) easy-assigns))
                          (t
                           (return nil)))))))
        ;; Case with EASY or no ASSIGN's
        `(,mode . (lambda ,(tunbinds arglist)
                    ,local-declares
                    ,@easy-assigns
                    ,@body))
        ;; Case with arbitrary ASSIGN's.
        (let ((temps (mapcar #'(lambda (ign) ign (tr-gensym)) arglist)))
          `(,mode . (lambda ,temps
                      (unwind-protect
                           (progn
                             ;; [1] Check before binding.
                             ,@(mapcan #'(lambda (var val)
                                           (let ((assign (get var 'assign)))
                                             (if assign
                                               (let ((assign-fn (if (symbolp assign) `(quote ,assign) (coerce assign 'function))))
                                                 (list `(funcall ,assign-fn ',var ,val))))))
                                       arglist temps)
                             ;; [2] do the binding.
                             ((lambda ,(tunbinds arglist)
                                ,local-declares
                                ,@body)
                              ,@temps))
                        ;; [2] check when unbinding too.
                        ,@(mapcan #'(lambda (var)
                                      (let ((assign (get var 'assign)))
                                        (if assign
                                          (let ((assign-fn (if (symbolp assign) `(quote ,assign) (coerce assign 'function))))
                                            (list `(funcall ,assign-fn ',var
                                                    ;; use DTRANSLATE to
                                                    ;; catch global
                                                    ;; scoping if any.
                                                    ,(dtranslate var)))))))
                                  arglist))))))))


(defun make-declares (varlist localp &aux (dl) (fx) (fl) specs)
  (do ((l varlist (cdr l))
       (mode) (var))
      ((null l))

    ;; When a variable is declared special, be sure to declare it
    ;; special here.
    (when (and localp (tr-get-special (car l)))
      (push (car l) specs))

    (when (or (not localp)
              (not (tr-get-special (car l))))
      ;; don't output local declarations on special variables.
      (setq var (teval (car l)) mode (value-mode var))
      (setq specs (cons var specs))

      (cond ((eq '$fixnum mode) (pushnew var fx :test #'eq))
            ((eq '$float mode)  (pushnew var fl :test #'eq)))))
  (if fx (pushnew `(fixnum  . ,fx) dl :test #'eq))
  (if fl (pushnew `(type flonum  . ,fl) dl :test #'eq))
  (if specs (pushnew `(special  . ,specs) dl :test #'eq))
  (if dl `(declare . ,dl)))

(defun tr-seq (l)
  (do ((mode nil)
       (body nil))
      ((null l)
       (cons mode (nreverse body)))
    (let ((exp (translate (pop l))))
      (setq mode (car exp))
      (push (cdr exp) body))))

(def%tr mprogn (form)
  (setq form (tr-seq (cdr form)))
  (cons (car form) `(progn ,@(cdr form))))
        
(defun go-tag-p (e)
  (or (symbolp e) (integerp e)))

(def%tr mprog (form)
  (let (arglist body val-list)
    ;; [1] normalize the MPROG syntax.
    (cond (($listp (cadr form))
           (setq arglist (cdadr form)
                 body (cddr form)))
          (t
           (setq arglist nil
                 body (cdr form))))
    (cond ((null body)
           (setq body '(((mquote) $done)))))
    (setq val-list (mapcar #'(lambda (u)
                               (if (atom u) u
                                   (translate (caddr u))))
                           arglist)
          arglist (mapcar #'(lambda (u)
                              ;;  X or ((MSETQ) X Y)
                              (if (atom u) u (cadr u)))
                          arglist))
    (let ((dup (find-duplicate arglist :test #'eq)))
      (when dup
        (tr-format (intl:gettext "error: ~M occurs more than once in block variable list") dup)
        (setq tr-abort t)
        (return-from mprog nil)))
    (setq form
          (tr-lambda
           ;; [2] call the lambda translator.
           `((lambda) ((mlist) ,@arglist) ,@body)
           ;; [3] supply our own body translator.
           #'tr-mprog-body
           val-list
           arglist))
    (cons (car form) `(,(cdr form) ,@val-list))))

(defun tr-mprog-body (body val-list arglist
                      &aux 
                      (inside-mprog t)
                      (return-mode nil)
                      (need-prog? nil)
                      (returns nil) ;; not used but must be bound.
                      )
  (do ((l nil))
      ((null body)
       ;; [5] hack the val-list for the mode context.
       ;; Perhaps the only use of the function MAP in all of macsyma.
       (mapl #'(lambda (val-list arglist)
                 (cond ((atom (car val-list))
                        (rplaca val-list
                                (or (cdr (assoc (value-mode (car arglist))
                                                mode-init-value-table :test #'eq))
                                    `',(car arglist))))
                       (t
                        (warn-mode (car arglist)
                                   (value-mode (car arglist))
                                   (car (car val-list))
                                   "in a `block' statement")
                        (rplaca val-list (cdr (car val-list))))))
             val-list arglist)
       (setq l (nreverse l))
       (cons return-mode
             (if need-prog?
                 `((prog () ,@(delete nil l :test #'equal)))
                 l)))
    ;; [4] translate a form in the body
    (let ((form (pop body)))
      (cond ((null body)
             ;; this is a really bad case.
             ;; we don't really know if the return mode
             ;; of the expression is for the value of the block.
             ;; Some people write RETURN at the end of a block
             ;; and some don't. In any case, the people not
             ;; use the PROG programming style won't be screwed
             ;; by this.
             (setq form (translate form))
             (setq return-mode (*union-mode (car form) return-mode))
             (setq form (cdr form))
             (if (and need-prog?
                      (or (atom form)
                          (not (eq (car form) 'return))))
                 ;; put a RETURN on just in case.
                 (setq form `(return ,form))))
            ((go-tag-p form))
            (t
             (setq form (dtranslate form))))
      (push form l))))

(def%tr mreturn (form)
  (if (null inside-mprog)
      (tr-format (intl:gettext "warning: 'return' not within 'block' or 'do': ~:M~%") form))
  (setq need-prog? t)
  (setq form (translate (cadr form)))
  (setq return-mode (if return-mode (*union-mode (car form) return-mode)
                        (car form)))
  (setq form `(return ,(cdr form)))
  (push form returns) ;; USED by lusing MDO etc not yet re-written.
  ;; MODE here should be $PHANTOM or something.
  `($any . ,form))

(def%tr mgo (form)
  (if (null inside-mprog)
      (tr-format (intl:gettext "warning: 'go' not within 'block' or 'do': ~:M~%") form))
  (if (not (go-tag-p (cadr form)))
      (tr-format (intl:gettext "warning: 'go' tag must be a symbol or an integer: ~:M~%") form))
  (setq need-prog? t)
  `($any . (go ,(cadr form))))

(def%tr mqapply (form)
  (let     ((fn (cadr form)) (args (cddr form)) 
            (aryp (member 'array (cdar form) :test #'eq)))
    (cond ((atom fn) 
           ;; I'm guessing (ATOM FN) is a parser error or other Lisp error,
           ;; so don't bother to translate the following error message.
           (tr-format "translator: MQAPPLY operator must be a cons; found: ~:M" form)
           nil)
          ((eq (caar fn) 'mquote) 
           `($any list ',(cons (cadr fn) aryp) ,@(tr-args args)))
          ((eq (caar fn) 'lambda)
           (let ((args (tr-args args))
                 (fn (translate fn)))
             (cons (car fn) `(mfuncall ,(cdr fn) ,@args))))
          ((not aryp)
           `($any simplify (mapply ,(dconvx (translate fn))
                            (list ,@(tr-args args))
                            ',fn)))
          (t
           (warn-meval form)
           (punt-to-meval form)))))



(def%tr mcond (form) 
  (prog (dummy mode nl) 
     (setq dummy (translate (caddr form)) 
           mode (car dummy) 
           nl (list dummy (translate-predicate (cadr form))))
     (do ((l (cdddr form) (cddr l))) ((null l))
       ; Optimize the else-if case: if we're at the else case at the end
       ; and the body is just another conditional, then we just continue
       ; directly with the clauses of the inner conditional instead of
       ; nesting.
       (when (and (null (cddr l))
                  (eq (car l) t)
                  (consp (cadr l))
                  (eq (caaadr l) 'mcond))
         (setq l (cdadr l)))
       (setq dummy (translate (cadr l)) 
             mode (*union-mode mode (car dummy)) 
             nl (cons dummy
                      (cons (translate-predicate (car l))
                            nl))))
     ; We leave off the final clause if the condition is true
     ; and the consequent is false.
     (when (and (eq t (cadr nl)) (null (cdar nl)))
       (setq nl (cddr nl)))
     (setq form nil)
     (do ((l nl (cddr l))) ((null l))
       (setq form
             (cons (cons (cadr l)
                         (cond ((and (not (atom (cdar l)))
                                     (cddar l)
                                     (eq (cadar l) 'progn))
                                (nreverse 
                                 (cons (dconv (cons (caar l)
                                                    (car (reverse (cddar l))))
                                              mode)
                                       (cdr (reverse (cddar l))))))
                               ((and (equal (cdar l) (cadr l))
                                     (atom (cdar l))) nil)
                               (t (list (cdr (car l))))))
                   form)))
     ;; Wrap (LET (($PREDERROR T)) ...) around translation of MCOND.
     ;; Nested MCOND expressions (e.g. if x > 0 then if y > 0 then ...)
     ;; will therefore yield nested (LET (($PREDERROR T)) ... (LET (($PREDERROR T)) ...)).
     ;; I suppose only the topmost one is needed, but there is very little harm
     ;; in the redundant ones, so I'll let it stand.
     (return (cons mode (list 'let '(($prederror t)) (cons 'cond form))))))



;; The MDO and MDOIN translators should be changed to use the TR-LAMBDA.
;; Perhaps a mere expansion into an MPROG would be best.

(def%tr mdo (form)
  (let (returns assigns return-mode (inside-mprog t) need-prog?)
    (let (mode var init next test action varmode)
      (setq var (cond ((cadr form)) (t 'mdo)))
      (tbind var)
      (setq init (if (caddr form) (translate (caddr form)) '($fixnum . 1)))
      (cond ((not (setq varmode (tr-get-mode var)))
             (declvalue var (car init) t)))
      (setq next (translate (cond ((cadddr form) (list '(mplus) (cadddr form) var))
                                  ((car (cddddr form)))
                                  (t (list '(mplus) 1 var)))))
      (setq form (copy-list form))
      ;;to make the end test for thru be numberp if the index is numberp
      ;;and to eliminate reevaluation
      (cond ((not varmode)
             (declvalue var (*union-mode (car init) (car next)) t))
            (t
             (warn-mode var varmode (*union-mode (car init) (car next)))))
      (setq test (translate-predicate
                  (list '(mor)
                        (cond ((null (cadr (cddddr form)))  nil)
                              ((and (cadddr form)
                                    (mnegp ($numfactor (simplify (cadddr form)))))
                               (list '(mlessp) var (cadr (cddddr form))))
                              (t (list '(mgreaterp) var (cadr (cddddr form)))))
                        (caddr (cddddr form)))))
      (setq action (translate (cadddr (cddddr form)))
            mode (cond ((null returns) '$any)
                       (t return-mode)))
      (setq var (tunbind (cond ((cadr form)) (t 'mdo))))
      `(,mode do ((,var ,(cdr init) ,(cdr next)))
              (,test '$done) . ((declare (special ,var)) .
              ,(cond ((atom (cdr action)) nil)
                     ((eq 'progn (cadr action)) (cddr action))
                     (t (list (cdr action)))))))))

(def%tr mdoin (form)
  (let (returns assigns return-mode (inside-mprog t) need-prog?)
    (prog (mode var init action)
       (setq var (tbind (cadr form))) (tbind 'mdo)
       (setq init (dtranslate (caddr form)))
       (cond ((or (cadr (cddddr form)) (caddr (cddddr form)))
              (tunbind 'mdo) (tunbind (cadr form))
              (return (punt-to-meval `((mdoin) . ,(cdr form))))))
       (setq action (translate (cadddr (cddddr form)))
             mode (cond ((null returns) '$any)
                        (t return-mode)))
       (tunbind 'mdo) (tunbind (cadr form))
       (return
         `(,mode do ((,var) (mdo (cdr ,init) (cdr mdo)))
                 ((null mdo) '$done) .
                  ((declare (special ,var)) (setq ,var (car mdo)) .
                 ,(cond ((atom (cdr action)) nil)
                        ((eq 'progn (cadr action)) (cddr action))
                        (t (list (cdr action))))))))))


(defun lambda-wrap1 (tn val form)
  (if (or (atom val)
          (eq (car val) 'quote))
      (subst val tn form)
      `((lambda (,tn) ,form) ,val)))
          
(def%tr msetq (form)
  (let ((var (cadr form))
        (val (caddr form))
        assign
        mode)
    (cond ((atom var)
           (setq mode (value-mode var) val (translate val))
           (warn-mode var mode (car val))
           (if (eq '$any mode)
               (setq mode (car val) val (cdr val))
               (setq val (dconv val mode)))
           (cons mode
                 (if (setq assign (get var 'assign))
                     (let ((tn (tr-gensym))
                           (assign-fn (if (symbolp assign) `(quote ,assign) (coerce assign 'function))))
                       (lambda-wrap1 tn val `(let nil
                                              (declare (special ,var ,(teval var)))
                                              (funcall ,assign-fn ',var ,tn)
                                              (setq ,(teval var) ,tn))))
                     `(let nil (declare (special ,(teval var)))
                        (if (not (boundp ',(teval var)))
                            (add2lnc ',(teval var) $values))
                        (,(if *macexpr-top-level-form-p*
                              'defparameter
                              'setq)
                         ,(teval var) ,val)))))
          ((member 'array (car var) :test #'eq)
           (tr-arraysetq var val))
          (t
           (unless (safe-get (caar var) 'mset_extension_operator)
         (tr-format (intl:gettext "warning: no assignment operator known for ~:M~%") var)
         (tr-format (intl:gettext "note: just keep going and hope for the best.~%")))
           (setq val (translate val))
           `(,(car val) mset ',var ,(cdr val))))))

(def%tr $max (x) (translate-$max-$min x))
(def%tr $min (x) (translate-$max-$min x))
(def%tr %max (x) (translate-$max-$min x))
(def%tr %min (x) (translate-$max-$min x))

(defun translate-$max-$min (form)
  (let   ((mode) (arglist) (op (stripdollar (caar form))))
    (setq arglist
          (mapcar (lambda (l)
                    (setq l (translate l))
                    (cond ((null mode)
                           (setq mode (car l)))
                          ((eq mode (car l)))
                          (t
                           (setq mode '$any)))
                    l)
                  (cdr form)))
    ; To match the interpreted case, and to make sure we use the
    ; correct mode for the return value, we do not apply float
    ; contagion to the arguments and we use a special translation
    ; to call MAX or MIN only when every argument has the same
    ; mode (either all fixnum or all float).  CLHS says that
    ; implementations have choices they can make about what MAX
    ; and MIN return when the arguments are a mix of float and
    ; rational types.
    ; Example: if an implementation decides to apply float contagion
    ; to the arguments of MAX (MIN), then it can return either an
    ; integer or a float if the greatest (least) argument was an
    ; integer.
    (if (member mode '($fixnum $float) :test #'eq)
        `(,mode  ,(if (eq 'min op) 'min 'max) . ,(mapcar 'cdr arglist))
        `($any ,(if (eq 'min op) '$lmin '$lmax)
          (list '(mlist) . ,(mapcar 'dconvx arglist))))))


;;; mode acessing, binding, handling. Super over-simplified.

(defun tr-class (x)
  (cond ((integerp x) '$fixnum)
        ((floatp x) '$float)
        ((member x '(t nil) :test #'eq) '$boolean)
        ((atom x) '$any)
        ((eq 'rat (caar x)) '$rational)
        (t '$any)))

(defun *union-mode (mode1 mode2) 
  (cond ((eq mode1 mode2) mode1)
        ((null mode1) mode2)
        ((null mode2) mode1)
        ((member mode2 *$any-modes* :test #'eq) '$any)
        ((member mode1 *$any-modes* :test #'eq) '$any)
        ((eq '$fixnum mode1) mode2)
        ((eq '$float mode1)
         (if (eq '$number mode2) '$number '$float))
        ((eq '$rational mode1)
         (if (eq '$float mode2) '$float '$any))
        ((eq '$number mode1)
         (if (eq '$rational mode2) '$any '$number))
        (t '$any)))

(defun value-mode (var)
  (cond ((tr-get-mode var))
        (t
         (warn-undeclared var)
         '$any)))

(defun decmode-arrayfun (f m)
  (putprop f m 'arrayfun-mode))

(defun array-mode (ar)
  (cond ((get ar 'array-mode)) (t '$any)))

(defun arrayfun-mode (ar)
  (cond ((get ar 'arrayfun-mode)) (t '$any)))

(defun function-mode (f)
  (cond ((get f 'function-mode)) (t '$any)))

(defun function-mode-@ (f)
  (ass-eq-ref (tr-get-val-modes f) 'function-mode '$any))

(defun array-mode-@ (f)
  (ass-eq-ref (tr-get-val-modes f) 'array-mode '$any))


(defvar $tr_bind_mode_hook nil
  "A hack to allow users to key the modes of variables
  off of variable spelling, and other things like that.")

;; TBIND, below, copies the MODE, VAL-MODES, and SPECIAL properties
;; into the a table named TSTACK, and then removes those properties.
;; So if TBIND has been called, we will need to look for those
;; properties in TSTACK instead of the symbol property list.

(defstruct (tstack-slot (:conc-name tstack-slot-))
  mode 
  tbind
  val-modes
  ;; an alist telling second order info
  ;; about APPLY(VAR,[X]), ARRAYAPPLY(F,[X]) etc.
  special)

(defun tr-get-mode (a)
  (if (get a 'tbind)
    (let ((my-slot (cdr (assoc a tstack))))
      (tstack-slot-mode my-slot))
    (get a 'mode)))

#-gcl (defun (setf tr-get-mode) (b a)
  (if (get a 'tbind)
    (let ((my-slot (cdr (assoc a tstack))))
      (setf (tstack-slot-mode my-slot) b))
    (setf (get a 'mode) b)))

#+gcl (defsetf tr-get-mode (a) (b)
 `(if (get ,a 'tbind)
    (let ((my-slot (cdr (assoc ,a tstack))))
      (setf (tstack-slot-mode my-slot) ,b))
    (setf (get ,a 'mode) ,b)))

(defun tr-get-val-modes (a)
  (if (get a 'tbind)
    (let ((my-slot (cdr (assoc a tstack))))
      (tstack-slot-val-modes my-slot))
    (get a 'val-modes)))

#-gcl (defun (setf tr-get-val-modes) (b a)
  (if (get a 'tbind)
    (let ((my-slot (cdr (assoc a tstack))))
      (setf (tstack-slot-val-modes my-slot) b))
    (setf (get a 'val-modes) b)))

#+gcl (defsetf tr-get-val-modes (a) (b)
 `(if (get ,a 'tbind)
    (let ((my-slot (cdr (assoc ,a tstack))))
      (setf (tstack-slot-val-modes my-slot) ,b))
    (setf (get ,a 'val-modes) ,b)))

(defun tr-get-special (a)
  (if (get a 'tbind)
    (let ((my-slot (cdr (assoc a tstack))))
      (tstack-slot-special my-slot))
    (get a 'special)))

#-gcl (defun (setf tr-get-special) (b a)
  (if (get a 'tbind)
    (let ((my-slot (cdr (assoc a tstack))))
      (setf (tstack-slot-special my-slot) b))
    (setf (get a 'special) b)))

#+gcl (defsetf tr-get-special (a) (b)
 `(if (get ,a 'tbind)
    (let ((my-slot (cdr (assoc ,a tstack))))
      (setf (tstack-slot-special my-slot) ,b))
    (setf (get ,a 'special) ,b)))
;;;
;;; should be a macro (TBINDV <var-list> ... forms)
;;; so that TUNBIND is assured, and also so that the stupid ASSQ doesn't
;;; have to be done on the darn TSTACK. This will have to wait till
;;; the basic special form translation properties are rewritten.

(defun variable-p (var)
  (and var (symbolp var) (not (eq var t))))

(defun bad-var-warn (var)
  (tr-format (intl:gettext "warning: ~:M cannot be used as a variable.~%") var))

(defun tbind (var &aux old)
  (cond ((variable-p var)
         (setq old (make-tstack-slot :mode (get var 'mode)
                                     :tbind (get var 'tbind)
                                     :val-modes (get var 'val-modes)
                                     :special (get var 'special)))
         (push (cons var old) tstack)
         (cond ((not (specialp var))
                ;; It is the lisp convention in use to inherit
                ;; specialness from higher context.
                ;; Spurious MODEDECLARATIONS get put in the environment
                ;; when code is MEVAL'd since there is no way to stack
                ;; the mode properties. Certainly nobody is willing
                ;; to hack MEVAL in JPG;MLISP
                (remprop var 'val-modes)
                (remprop var 'mode)
                (remprop var 'special)))
         (putprop var var 'tbind)
         (if $tr_bind_mode_hook
             (let ((mode? (mapply $tr_bind_mode_hook
                                  (list var)
                                  '$tr_bind_mode_hook)))
               (if mode? (tr-declare-varmode var mode?))))
         var)
        (t
         (bad-var-warn var))))

(defun tunbind (var &aux (old (assoc var tstack :test #'eq)))
  (when (variable-p var)
    (prog1
        (teval var)
      (cond (old
             (setq tstack (delete old tstack :test #'eq)) ; POP should be all we need.
             (setq old (cdr old))
             (putprop1 var (tstack-slot-mode old) 'mode)
             (putprop1 var (tstack-slot-tbind old) 'tbind)
             (putprop1 var (tstack-slot-val-modes old) 'val-modes)
             (putprop1 var (tstack-slot-special old) 'special))))))

(defun putprop1 (name value key)
  ;; leaves property list clean after unwinding, this
  ;; is an efficiency/storage issue only.
  (if value
      (putprop name value key)
      (progn
        (remprop name key)
        nil)))

(defun tunbinds (l)
  (do ((nl))
      ((null l) nl)
    (setq nl (cons (tunbind (caar tstack)) nl)
          l (cdr l))))

(defun tboundp (var)
  ;; really LEXICAL-VARP.
  (and (symbolp var) (get var 'tbind) (not (tr-get-special var))))

(defun teval (var)
  (or (and (symbolp var) (get var 'tbind)) var))

;; Local Modes:
;; Mode: LISP
;; Comment Col: 40
;; END: