Re: no class-of ?

[Jamison Hope <jrh@theptrgroup.com>]

On Sep 22, 2017, at 6:26 PM, Per Bothner <per@bothner.com> wrote:
> 
> On 09/22/2017 03:18 PM, Jamison Hope wrote:
>> OK, so if I understand correctly, I can't use a macro for this, but what
>> I can do instead is write a function that always gets inlined.  The
>> function itself doesn't really have to do anything, because the real
>> work will be done in the validate-apply handler that rewrites the
>> procedure application to a new Expression.  And there, I can decide what
>> kind of Expression to construct based upon the Type of the argument
>> expression.
> 
> 100% correct.

I found isEofValidateApply, which is extremely similar in form to what I
want, so I started with this:

(import (kawa expressions))

(module-export ensure-boolean validateEnsureBoolean)

(define (ensure-boolean o)
  validate-apply: "test:validateEnsureBoolean"
  (if o #t #f))

(define-validate validateEnsureBoolean (exp required proc)
  ((exp:isSimple 1 1)
   (exp:visitArgs (get-visitor))
   (let* ((e0 (exp:getArg 0))
          (t0 (e0:getType)))
     (cond ((eq? t0 boolean) e0)
           (else exp)))))


But I get a java.lang.Error when I try to compile that:


(compiling test.scm to test)
Exception in thread "main" java.lang.Error: gnu.kawa.lispexpr.LangPrimType does not implement Externalizable
	at gnu.expr.LitTable.error(LitTable.java:122)
	at gnu.expr.LitTable.writeObject(LitTable.java:282)
	at gnu.expr.LitTable.emit(LitTable.java:85)
	at gnu.expr.Compilation.generateBytecode(Compilation.java:2015)
	at gnu.expr.Compilation.process(Compilation.java:1810)
	at gnu.expr.ModuleInfo.loadByStages(ModuleInfo.java:310)
	at gnu.expr.ModuleInfo.loadByStages(ModuleInfo.java:292)
	at kawa.repl.compileFiles(repl.java:780)
	at kawa.repl.processArgs(repl.java:441)
	at kawa.repl.main(repl.java:820)


If I change the test to "(eq? t0 integer)" or "(eq? t0 byte)", then it
compiles without error, so it's something about boolean in particular.


--
Jamison Hope
The PTR Group
www.theptrgroup.com