;;; "paramlst.scm" passing parameters by name.
; Copyright 1995 Aubrey Jaffer
;
;Permission to copy this software, to redistribute it, and to use it
;for any purpose is granted, subject to the following restrictions and
;understandings.
;
;1.  Any copy made of this software must include this copyright notice
;in full.
;
;2.  I have made no warrantee or representation that the operation of
;this software will be error-free, and I am under no obligation to
;provide any services, by way of maintenance, update, or otherwise.
;
;3.  In conjunction with products arising from the use of this
;material, there shall be no use of my name in any advertising,
;promotional, or sales literature without prior written consent in
;each case.

;;; Format of arity-spec: (name predicate conversion)

(require 'common-list-functions)

(define arity->arity-spec
  (let ((table
	 `((nary
	    ,(lambda (a) #t)
	    ,identity)
	   (nary1
	    ,(lambda (a) (not (null? a)))
	    ,identity)
	   (single
	    ,(lambda (a) (and (pair? a) (null? (cdr a))))
	    ,car)
	   (optional
	    ,(lambda (a) (or (null? a) (and (pair? a) (null? (cdr a)))))
	    ,identity)
	   (boolean
	    ,(lambda (a)
	       (or (null? a)
		   (and (pair? a) (null? (cdr a)) (boolean? (car a)))))
	    ,(lambda (a) (if (null? a) #f (car a)))))))
    (lambda (arity)
      (assq arity table))))

(define (fill-empty-parameters defaults parameter-list)
  (map (lambda (default parameter)
	 (cond ((null? (cdr parameter))
		(cons (car parameter)
		      (if default (default parameter-list) '())))
	       (else parameter)))
       defaults parameter-list))

(define (check-parameters checks parameter-list)
  (for-each (lambda (check parameter)
	      (for-each
	       (lambda (p)
		 (cond ((and check (not (check p)))
			(slib:error "parameter is wrong type: " p))))
	       (cdr parameter)))
	    checks parameter-list)
  parameter-list)

(define (check-arities arity-specs parameter-list)
  (and (every identity arity-specs)
       (every
	(lambda (arity-spec param)
	  ((cadr arity-spec) (cdr param)))
	arity-specs parameter-list)))

(define (parameter-list->arglist positions arities parameter-list)
  (and (= (length arities) (length positions) (length parameter-list))
       (let ((arity-specs (map arity->arity-spec arities))
	     (ans (make-vector (length positions) #f)))
	 (and (check-arities arity-specs parameter-list)
	      (for-each
	       (lambda (pos arity-spec param)
		 (vector-set! ans (+ -1 pos)
			      ((caddr arity-spec) (cdr param))))
	       positions arity-specs parameter-list)
	      (vector->list ans)))))

(define (make-parameter-list parameter-names)
  (map list parameter-names))

(define (parameter-list-ref parameter-list i)
  (let ((ans (assoc i parameter-list)))
    (and ans (cdr ans))))

(define (parameter-list-expand expanders parms)
  (do ((lens (map length parms) (map length parms))
       (olens '() lens))
      ((equal? lens olens))
    (for-each (lambda (expander parm)
		(cond
		 (expander
		  (for-each
		   (lambda (news)
		     (cond ((adjoin-parameters! parms news))
			   (else (slib:error
				  "expanded feature unknown: " news))))
		   (apply append
			  (map (lambda (p)
				 (cond ((expander p))
				       ((not '()) '())
				       (else (slib:error
					      "couldn't expand feature: " p))))
			       (cdr parm)))))))
	      expanders
	      parms)))

(define (adjoin-parameters! parameter-list . parameters)
  (let ((apairs (map (lambda (param)
		       (cond ((pair? param)
			      (assoc (car param) parameter-list))
			     (else (assoc param parameter-list))))
		     parameters)))
    (and (every identity apairs)	;same as APPLY AND?
	 (for-each
	  (lambda (apair param)
	    (cond ((pair? param)
		   (for-each (lambda (o)
			       (if (not (member o (cdr apair)))
				   (set-cdr! apair (cons o (cdr apair)))))
			     (cdr param)))
		  (else (if (not (memv #t (cdr apair)))
			    (set-cdr! apair (cons #t (cdr apair)))))))
	  apairs parameters)
	 parameter-list)))

(define (getopt->parameter-list argc argv optnames arities types aliases)
  (define (can-take-arg? opt)
    (not (eq? (list-ref arities (position opt optnames))
	      'boolean)))
  (define (coerce-val val curopt)
    (define ntyp (list-ref types (position curopt optnames)))
    (case ntyp
      ((expression) val)
      (else (coerce val ntyp))))
  (require 'getopt)
  (let ((optlist '())
	(long-opt-list '())
	(optstring #f)
	(parameter-list (make-parameter-list optnames))
	(curopt '*unclaimed-argument*))
    (set! aliases (map (lambda (alias)
			 (define str (string-copy (car alias)))
			 (do ((i (+ -1 (string-length str)) (+ -1 i)))
			     ((negative? i) (cons str (cdr alias)))
			   (cond ((char=? #\ (string-ref str i))
				  (string-set! str i #\-)))))
		       aliases))
    (for-each
     (lambda (alias)
       (define opt (car alias))
       (cond ((not (string? opt)))
	     ((< 1 (string-length opt))
	      (set! long-opt-list (cons opt long-opt-list)))
	     ((not (= 1 (string-length opt))))
	     ((can-take-arg? (cadr alias))
	      (set! optlist (cons (string-ref opt 0)
				  (cons #\: optlist))))
	     (else (set! optlist (cons (string-ref opt 0) optlist)))))
     aliases)
    (set! optstring (list->string (cons #\: optlist)))
    (let loop ()
      (let ((opt (getopt-- argc argv optstring)))
	(case opt
	  ((#\: #\?)
	   (slib:error
	    'getopt->parameter-list "unrecognized option"
	    getopt:opt))
	  ((#f)
	   (cond ((and (< *optind* argc)
		       (string=? "-" (list-ref argv *optind*)))
		  (set! *optind* (+ 1 *optind*)))
		 ((< *optind* argc)
		  (cond ((adjoin-parameters!
			  parameter-list
			  (list curopt
				(coerce-val (list-ref argv *optind*)
					    curopt)))
			 (set! *optind* (+ 1 *optind*))
			 (loop))
			(else (slib:error 'getopt->parameter-list curopt
					  (list-ref argv *optind*)
					  "not supported"))))))
	  (else
	   (cond ((char? opt) (set! opt (string opt))))
	   (let ((topt (assoc opt aliases)))
	     (cond (topt (set! topt (cadr topt)))
		   (else (slib:error "Option not recognized -" opt)))
	     (cond
	      ((not (can-take-arg? topt))
	       (adjoin-parameters! parameter-list (list topt #t)))
	      (*optarg*
	       (set! curopt topt)
	       (adjoin-parameters! parameter-list
				   (list topt (coerce-val *optarg* curopt))))
	      (else
	       (set! curopt topt)
	       (rdms:warn "No argument for option -" opt))))
	   (loop)))))
    parameter-list))

(define (getopt->arglist argc argv optnames positions
			 arities types defaults checks aliases)
  (let* ((params (getopt->parameter-list
		  argc argv optnames arities types aliases))
	 (fparams (fill-empty-parameters defaults params)))
    (and (list? params) (check-parameters checks fparams))
    (and (list? params) (parameter-list->arglist positions arities fparams))))
