From: Per Bothner <per@bothner.com>
To: Duncan Mak <duncanmak@gmail.com>,
kawa mailing list <kawa@sourceware.org>
Subject: Re: Reflection on function argument types
Date: Sun, 01 Jan 2017 18:19:00 -0000 [thread overview]
Message-ID: <10f01de4-d72f-799c-795c-9a078ebfa239@bothner.com> (raw)
In-Reply-To: <CABgWrqqcC2v96NiJ_m7MqFBRtjpbFy0FaoWDKLULmtgS3vTNEQ@mail.gmail.com>
On 12/27/2016 09:34 PM, Duncan Mak wrote:
> I wrote the following code:
>
> (import (srfi 1))
> (define (foo (a :: integer)) (+ a a))
> (define (hello-number (n :: number) (i :: number)) (list "number" n))
> (define (hello-string (s :: string)) (list "string" s))
> (define (print-types (func :: gnu.mapping.MethodProc))
> (display (procedure-property func 'name)) (newline)
> (for-each (lambda (t) (display t) (newline))
> (map (lambda (i) (func:getParameterType i)) (iota
> (func:numParameters))))
> (newline))
> (print-types foo)
> (print-types hello-number)
> (print-types hello-string)
>
> I'm surprise to see that the output differs between foo and hello-*:
>
> foo
> Type integer
>
> hello-number
> ClassType java.lang.Object
> ClassType java.lang.Object
>
> hello-string
> ClassType java.lang.Object
>
> Why is it that I only see java.lang.Object for the hello-* functions?
> Shouldn't number and string show up, like it did for foo?
This turns out to be a problem with demangling. 'foo' works because
it doesn't have any special characters.
In ModuleMethod.java in resolveParameterTypes it says:
String mangledName = Mangling.mangleNameIfNeeded(name);
but it should be:
String mangledName = Mangling.mangleName(name);
Unfortunately, fixing this improves the accuracy of type-checking
enough to cause some problems. For example this code
(simplified from r7rs-tests.scm):
(let ((val 'abc))
(cond ((and (complex? val)
(not (nan? val)))
(display val))))
Kawa complains that the call to nan? is invalid because the argument val
is a symbol. This is bogus, since the previous test to complex? ensures
nan? is never called.
I created this issue:
https://gitlab.com/kashell/Kawa/issues/1
--
--Per Bothner
per@bothner.com http://per.bothner.com/
prev parent reply other threads:[~2017-01-01 18:19 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-28 5:38 Duncan Mak
2017-01-01 18:19 ` Per Bothner [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=10f01de4-d72f-799c-795c-9a078ebfa239@bothner.com \
--to=per@bothner.com \
--cc=duncanmak@gmail.com \
--cc=kawa@sourceware.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).