#lang scheme/base
(require "../"
         (for-syntax scheme/base

;; Toplevel forms for dictionary construction and compilation for the
;; Staapl macro forth.

;; These forms assume particular namespace organization:
;;   * macro   op transformer namespace
;;   * target  instantiated op lists
;;   * inline  postponed instantiation macros for target words
;; The dictionary is in a special format: (define register! wrap name compile code ...)
;;   - define    = define-macro or define-forth
;;   - register! = called for each inline macro (used for instantiation)
;;   - wrap      = wrapper functions provided by compiler
;;   - name      = word name
;;   - compile   = semantics of (code ...)

(provide (all-defined-out))

(define-syntax macro-word
  (syntax-rules ()
    ((_ _ _ #f . _)  (begin)) ;; mode marker
    ((_ register! wrap name compile code ...)
     (ns (macro)
         (define name
           (wrap 'name #f (compile code ...)))))))

(define-syntax-rule (word-trap-anon) (begin))

(define-syntax define/false
  (syntax-rules ()
    ((_ _ #f _)   (begin)) ;; don't define anonymous words
    ((_ (n ...) name value) (ns (n ...) (define name value)))))

(define-syntax forth-word
  (syntax-rules ()
    ((_ register! wrap name compile code ...)
         (label wrapper inline)
         (wrap 'name #f (compile code ...)))
       (define/false (target) name label)
       (define/false (macro)  name wrapper)
       (define/false (inline) name inline)
       (register! inline)))))

;; Toplevel forms.

;; Similar to 'macro: but for a toplevel form.  Initialize dictionary
;; in 'forth' mode, but make sure the first line is invalid.
(define-syntax-rule (forth-begin/init init code ...)
  (rpn-parse (begin
             code ...))

(define-syntax-rule (provide-words w ...)
   ;; (ns-out (target) w) ...   ;; don't provide target words
   ;; (ns-out (inline) w) ...)
   (ns-out (macro) w) ...

;; Forth parsers.

;; ((provide-all) (|{| provide (all-defined-out) |}|))

 ((|'| name)       (',(macro name)))
 ((|`| name)       ('name))

 ((provide w)       (|{| provide-words w |}| ))

 ;;   ((variable name)  (create name 1 allot))
 ;;   ((2variable name) (create name 2 allot))
 ;;   ((vector name)    (2varable name))
 ;;   ((declare name)   (:macro name 'name undefined |;|))
 ;;   ((parameter name) (:macro name ,(make-constant 'name) |;|))
 ;;   ((string name)    (',(symbol->string 'name)))
 ;; Trouble with the word 'f->' being defined later...
 ;; ((fstring name)   (f-> string name |string,|))

 (define (with-mode def-word register! wrap)
    (lambda (name)
      #`(#,def-word #,register! #,wrap #,name rpn-lambda))))

 ;; ':' takes semantics from last entry.
 (define (last-mode register! forthword wrapword macroword wrapmacro)
    (lambda (d) ;; get-compile
      (let ((entry (d-last d)))
         (lambda (name)
           (syntax-case entry (macro-word)
             ((macro-word . _) #`(#,macroword #,register! #,wrapmacro #,name rpn-lambda))
             (else             #`(#,forthword #,register! #,wrapword #,name rpn-lambda)))))))))

 (define (stx->path it)
   (let ((it (syntax->datum it)))
      ((symbol? it) (string->path (symbol->string it)))
      ((string? it) (string->path it))
      ((path? it)   it)
       (raise-syntax-error #f "can't convert to path" it)))))

;; Non-hygienically instantiate Forth syntax parameterized by
;; registration and compilation functions.
(define-syntax (define-forth-parser stx)
  (syntax-case stx ()
    ((_ forth-begin (reg wrap-macro wrap-word wrap-variable))
      (;; defined:
       forth macro : :macro :forth :variable variable 2variable
       expand require require-file planet staapl

       ;; referenced:
            (define-syntax-rule (forth-begin . code)
              (forth-begin/init (forth-word reg wrap-word #f rpn-lambda) . code)) ;; (*)
            (ns (macro) (define-syntax :macro    (with-mode #'macro-word #'reg #'wrap-macro)))
            (ns (macro) (define-syntax :forth    (with-mode #'forth-word #'reg #'wrap-word)))
            (ns (macro) (define-syntax :variable (with-mode #'forth-word #'reg #'wrap-variable)))
            (ns (macro) (define-syntax :         (last-mode #'reg
                                                            #'forth-word #'wrap-word
                                                            #'macro-word #'wrap-macro)))

            ;; Recursive expansion.  This is necessary to make sure
            ;; 'require and 'define-syntax forms introduce transformer
            ;; bindings before continuing parsing.  It also needs to
            ;; serialize all dynamic context to the code stream.
            (ns (macro) (define-syntax expand
                           (lambda ()
                             (let ((form
                                       #,@(apply append
                                                 (for/list ((p (reverse (forth-path))))
                                                   #`(path #,p))))))
                               ;; (printf "expand: ~s\n" (syntax->datum form))
             ((forth) (:forth #f))
             ((macro) (:macro #f))

             ((variable n)   (:variable n 1 allot))  ;; FIXME: needs parameterization
             ((2variable n)  (:variable n 2 allot))  ;; FIXME: needs parameterization

             ;; These need expand because the require form might
             ;; introduce transformer bindings.
             ((require id)      (|{| require-id spec   id |}| expand))
             ((staapl id)       (|{| require-id staapl id |}| expand))
             ((planet id)       (|{| require-id planet id |}| expand))
             ((require-file id) (|{| require-id file   id |}| expand))


(ns (macro)
    (define-syntax provide-all
       (lambda (w d k)
         (k (w-cdr w)
             (datum->syntax (w-car w) ;; context needs to come from module
                            '(provide (all-defined-out)))

;; (*) The first word is anonymous.  It doesn't result in namespace
;; bindings but the postponed word is passed to register!  This is
;; mainly there to support compiler/assembler directives like 'org.

(ns (macro) (define-syntax load  ;; nested files
               (lambda (filename) ;; logger
                 (printf " include ~s\n" (path->string filename))))))

;; Inline s-expressions.  Note that if your current lexer allows, once
;; inside this construct ordinary s-expressions can be used.
(ns (macro) (define-syntax |{| rpn-curly-brace-transformer))

;; Ignore the '#lang syntax
(ns (macro) (define-syntax |#lang|
              (rpn-syntax-rules (planet)
                                ((_ planet spec) ())
                                ((_ spec) ()))))

;; Local lexical variables.
(require scheme/match)
(require "../comp/")
(define (macro-pop state n)
  (let-values (((state+ popped) (state-pop state n (ns (op ? qw)))))
    (apply values (cons state+ popped))))
(define-syntax-rule (macro-locals . a)
  (rpn-let-locals ((macro) macro: macro-pop) . a))
(ns (macro) (define-syntax \| (make-rpn-locals-transformer #'macro-locals)))
(ns (macro) (define-syntax path (make-rpn-path-transformer stx->path)))

;; Since there are no strings, how should this work?  Maybe use two
;; words: one that takes filenames directly and another one that uses
;; scheme symbols.
(define-syntax (require-id stx)
  ;; The whole form should have the caller's context to use caller's
  ;; 'require.
  (define req
    (syntax-case stx ()
      ((_ _ id)
       (lambda (sexpr)
         (datum->syntax #'id `(require ,sexpr))))))
  (syntax-case stx (spec file planet staapl)
    ((_ file id)   (req `(file ,(path->string (stx->path #'id)))))
    ((_ planet id) (req `(planet ,#'id)))
    ((_ staapl id) (req `(planet ,(string->symbol
                                   (format "zwizwa/staapl/~a"
                                           (syntax->datum #'id))))))))