Re: Wrapping up SRFI 177: Portable keyword arguments John Cowan (02 Mar 2020 23:53 UTC)
Re: Wrapping up SRFI 177: Portable keyword arguments Marc Feeley (03 Mar 2020 04:46 UTC)
Re: Wrapping up SRFI 177: Portable keyword arguments Marc Nieper-Wißkirchen (03 Mar 2020 06:29 UTC)
Re: Wrapping up SRFI 177: Portable keyword arguments Marc Nieper-Wißkirchen (03 Mar 2020 06:43 UTC)
Re: Wrapping up SRFI 177: Portable keyword arguments Marc Nieper-Wißkirchen (03 Mar 2020 07:51 UTC)
Identifier syntax, and using macros with call/kw Lassi Kortela (03 Mar 2020 08:57 UTC)
Re: Identifier syntax, and using macros with call/kw Shiro Kawai (03 Mar 2020 09:00 UTC)
Re: Identifier syntax, and using macros with call/kw Marc Nieper-Wißkirchen (03 Mar 2020 09:06 UTC)
Re: Identifier syntax, and using macros with call/kw Shiro Kawai (03 Mar 2020 09:19 UTC)
Re: Identifier syntax, and using macros with call/kw Marc Nieper-Wißkirchen (03 Mar 2020 09:48 UTC)
Re: Identifier syntax, and using macros with call/kw Shiro Kawai (03 Mar 2020 10:03 UTC)
Re: Identifier syntax, and using macros with call/kw Marc Nieper-Wißkirchen (03 Mar 2020 10:12 UTC)
Re: Identifier syntax, and using macros with call/kw John Cowan (06 Oct 2020 20:20 UTC)
Re: Identifier syntax, and using macros with call/kw Marc Nieper-Wißkirchen (07 Oct 2020 07:29 UTC)
Syntax for identifier syntax Lassi Kortela (03 Mar 2020 09:55 UTC)
Re: Syntax for identifier syntax Marc Nieper-Wißkirchen (03 Mar 2020 10:16 UTC)
Re: Syntax for identifier syntax John Cowan (03 Mar 2020 13:37 UTC)
Re: Syntax for identifier syntax Lassi Kortela (03 Mar 2020 13:42 UTC)
Re: Syntax for identifier syntax Marc Nieper-Wißkirchen (03 Mar 2020 14:59 UTC)
Re: Syntax for identifier syntax Jim Rees (04 Mar 2020 18:12 UTC)
Re: Syntax for identifier syntax Marc Nieper-Wißkirchen (04 Mar 2020 18:18 UTC)
Re: Syntax for identifier syntax John Cowan (04 Mar 2020 23:48 UTC)
Re: Identifier syntax, and using macros with call/kw Marc Nieper-Wißkirchen (03 Mar 2020 09:13 UTC)
R7RS-large backward compatibility Lassi Kortela (03 Mar 2020 10:31 UTC)
Re: R7RS-large backward compatibility Marc Nieper-Wißkirchen (03 Mar 2020 11:31 UTC)
Specifying a meeting point for different keyword systems Lassi Kortela (03 Mar 2020 11:56 UTC)
Re: Specifying a meeting point for different keyword systems Marc Nieper-Wißkirchen (03 Mar 2020 15:03 UTC)
Re: R7RS-large backward compatibility John Cowan (05 Mar 2020 19:36 UTC)
Re: R7RS-large backward compatibility Lassi Kortela (05 Mar 2020 19:51 UTC)
Re: R7RS-large backward compatibility John Cowan (05 Mar 2020 20:03 UTC)
Re: R7RS-large backward compatibility Lassi Kortela (05 Mar 2020 20:17 UTC)
Re: R7RS-large backward compatibility Marc Nieper-Wißkirchen (08 Mar 2020 09:00 UTC)
Re: R7RS-large backward compatibility Lassi Kortela (08 Mar 2020 09:06 UTC)
Re: R7RS-large backward compatibility John Cowan (08 Mar 2020 21:58 UTC)
Re: R7RS-large backward compatibility Lassi Kortela (08 Mar 2020 22:40 UTC)
Re: [scheme-reports-wg2] Re: R7RS-large backward compatibility Marc Nieper-Wißkirchen (09 Mar 2020 07:42 UTC)
Re: [scheme-reports-wg2] Re: R7RS-large backward compatibility Marc Nieper-Wißkirchen (09 Mar 2020 11:46 UTC)
Re: [scheme-reports-wg2] R7RS-large backward compatibility Lassi Kortela (09 Mar 2020 12:07 UTC)
Re: R7RS-large backward compatibility Per Bothner (09 Mar 2020 16:30 UTC)
Re: [scheme-reports-wg2] Re: R7RS-large backward compatibility Marc Nieper-Wißkirchen (09 Mar 2020 16:48 UTC)

Identifier syntax, and using macros with call/kw Lassi Kortela 03 Mar 2020 08:57 UTC

>         The difference is not subtle at all: macros resemble procedures
>         only in the general appearance of an invocation.  Lambda defines
>         a procedure, and even though there is no kw-apply, you can still
>         retrofit keywords to procedures and apply those procedures to
>         regular positional arguments without breaking them.
>
>     I agree with you that we would give up the ability of retrofitting
>     and that this would make keyword arguments much less useful.
>
> Having thought about this once more, I have to retract this point. With
> identifier syntax, it is very well possible to retrofit procedures with
> keyword arguments. A procedure with keyword arguments, even if it
> implemented as syntax, can still evaluate to an ordinary procedure when
> not used as a macro keyword.

This would require adding identifier syntax to R7RS-large, as you noted.

Unless I have misunderstood something, identifier syntax is basically
the same as symbol macros in Common Lisp. I Liked having them, but they
always seemed like there could be weird edge cases that blow up
unexpectedly. I never encountered any concrete problems with it, but
always felt like it shouldn't work that easily :)

One important use I'd like to preserve with kw args is higher-order
functions. With the current 177 you can make a lambda/kw and pass it to
another procedure that can call it using any of these:

- (foo args...)
- (apply foo args...)
- (call/kw foo args... (kws...))

That makes things really simple for users. I don't see a way to preserve
all of these possibilities without identifier syntax. Since 177 needs to
be usable immediately, it can't rely on new kinds of macros. That means
177 should probably specify lambda/kw to return real lambdas.

However, call/kw could be extended so it's allowed to call things that
are not real lambdas. Since call/kw is a macro that just expands to (foo
...), anything that is a valid procedure or macro call in the underlying
Scheme implementation should in principle work? I just thought of this
idea for the first time and may not understand all the details.