Re: evaluating syntax transformer threw unbound location first

[Panicz Maciej Godek <godek dot maciek at gmail dot com>]

> You can always add a:
>    ex.printStackTrace();
> before the:
>    return tr.syntaxError("evaluating syntax transformer '"
>
> I'd also try replacing first by car, to see if the issue
> is the (require 'srfi-1) not working as expected.

Thanks. I did replace everything from srfi with core functions,
and the "unbound location" error was solved (I have to admit
that decoding the error message was a littie bit tricky, because
I thought that the transformer threw unbound location first,
that is, before the evaluation ;] It would be helpful if the
symbol was put in quotes or was otherwise distinguished
typographically)

The macro that I sent had some other mistakes, but after
some corrections I got this:

(define-syntax define-application-views
  (lambda (stx)
    (syntax-case stx (show)
      ((define-application-views activity-name . names+views)
       (with-syntax ((show (datum->syntax #'define-application-views 'show)))
         #`(activity
            activity-name
            (on-create-view
             (letrec (#,@(datum->syntax
                        stx
                        (letrec ((range (lambda(start end)
                                          (if (= start end)
                                              '()
                                              `(,start
                                                ,@(range (+ 1 start) end))))))
                          (map (lambda (name+view id)
                                 `(,(car name+view) ::int ,id))
                               (syntax->datum #'names+views)
                               (range 0 (length (syntax->datum
#'names+views))))))
                    (activity-name ::android.widget.ViewFlipper
                     (view-flipper))
                    (show
                     (lambda (view)
                       ((as android.widget.ViewFlipper
                            activity-name):setDisplayedChild
                            view))))
               #,@(datum->syntax
                   stx
                   (map (lambda(name+view)
                          `((as android.widget.ViewFlipper
                                ,(syntax->datum #'activity-name)):addView
                                ,(cadr name+view)))
                        (syntax->datum #'names+views)))
               (as android.view.View activity-name)))))))))

Now I use the macro in the following way:

(expand/step #'(define-application-views mrok
  (short-view
   (button text: "Go to view 2"
           typeface: android.graphics.Typeface:SERIF
           on-click-listener: (lambda (_) (show long-view))))
  (long-view
   (button text: "Go to view 1"
           typeface: android.graphics.Typeface:SANS_SERIF
           on-click-listener: (lambda (_) (show short-view)))))

When I expand it using Racket's macro expander, it results with
the following code:

(activity
 mrok
 (on-create-view
  (letrec ((short-view ::int 0)
           (long-view ::int 1)
           (mrok ::android.widget.ViewFlipper (view-flipper))
           (show (lambda (view) ((as android.widget.ViewFlipper mrok)
:setDisplayedChild view))))
    ((as android.widget.ViewFlipper mrok)
     :addView
     (button
      text:
      "Go to view 2"
      typeface:
      android.graphics.Typeface:SERIF
      on-click-listener:
      (lambda (_) (show long-view))))
    ((as android.widget.ViewFlipper mrok)
     :addView
     (button
      text:
      "Go to view 1"
      typeface:
      android.graphics.Typeface:SANS_SERIF
      on-click-listener:
      (lambda (_) (show short-view))))
    (as android.view.View mrok))))

After I manually remove white spaces before :setDisplayedChild and
:addView, it works just as expected. However, when I use Kawa
to expand it, I get the following error:
"no declaration seen for unquote"

It refers to the line of the macro definition containing the code:
,(syntax->datum #'activity-name)):addView

(which is strange, because the unquote is used from within
quasiquote there)

When I expand the code with Kawa's expander (from syntax-utils),
the unquotes indeed remain in the resulting code:

(activity mrok
 (on-create-view
  (let
   ((short-view #!undefined) (long-view #!undefined) (mrok #!undefined)
    (show #!undefined))
   (begin (set short-view 0) (set long-view 1) (set mrok (view-flipper))
    (set show
     (lambda (view)
      ((: (as android.widget.ViewFlipper mrok) (quote setDisplayedChild))
       view)))
    ((:
      (as android.widget.ViewFlipper
       (unquote
        (syntax->datum
         (let
          ((#!null
            ((quote kawa.lang.TemplateScope kawa.lang.TemplateScope.make()))))
          ((quote
            java.lang.Object
kawa.lang.SyntaxTemplate.execute(java.lang.Object[],kawa.lang.TemplateScope))
           (quote kawa.lang.SyntaxTemplate@6d3f7281) (quote #!null) #!null)))))
      (quote addView))
     (button text: Go to view 2 on-click-listener:
      (lambda (_) (show long-view))))
    ((:
      (as android.widget.ViewFlipper
       (unquote
        (syntax->datum
         (let
          ((#!null
            ((quote kawa.lang.TemplateScope kawa.lang.TemplateScope.make()))))
          ((quote
            java.lang.Object
kawa.lang.SyntaxTemplate.execute(java.lang.Object[],kawa.lang.TemplateScope))
           (quote kawa.lang.SyntaxTemplate@6076ab2f) (quote #!null) #!null)))))
      (quote addView))
     (button text: Go to view 1 on-click-listener:
      (lambda (_) (show short-view))))
    (as android.view.View mrok)))))

What is the reason of this discrepancy and how could one possibly
overcome it?

Regards,
Panicz