* definitions in macros?
@ 2020-03-22 19:07 Han-Wen Nienhuys
2020-03-22 19:16 ` Matt Wette
2020-03-22 21:09 ` David Kastrup
0 siblings, 2 replies; 4+ messages in thread
From: Han-Wen Nienhuys @ 2020-03-22 19:07 UTC (permalink / raw)
To: Guile Devel; +Cc: lilypond-devel
Hi there,
in my quest to get lilypond working with GUILE 2+, I've hit another
stumbling block.
In order to make compilation with GUILE 2+ working, we have to move
away from runtime symbol definition (ie. module-define! calls).
In the code below, it looks like only one of the two definitions in
the body of my-macro-new takes effect. Is this expected, and if so,
why?
(defmacro-public my-macro-old (command-and-args . definition)
(module-define! (current-module) 'x1 "I am X1\n")
(module-define! (current-module) 'x2 "I am X2\n"))
(defmacro-public my-macro-new (command-and-args . definition)
`(define p "i am P\n")
`(define q "i am Q\n"))
(my-macro-old 1 2)
(my-macro-new 1 2)
(display x1)
(display x2)
(display q)
(display p)
thanks,
--
Han-Wen Nienhuys - hanwenn@gmail.com - http://www.xs4all.nl/~hanwen
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: definitions in macros?
2020-03-22 19:07 definitions in macros? Han-Wen Nienhuys
@ 2020-03-22 19:16 ` Matt Wette
2020-03-22 21:09 ` David Kastrup
1 sibling, 0 replies; 4+ messages in thread
From: Matt Wette @ 2020-03-22 19:16 UTC (permalink / raw)
To: guile-devel
On 3/22/20 12:07 PM, Han-Wen Nienhuys wrote:
> Hi there,
>
> in my quest to get lilypond working with GUILE 2+, I've hit another
> stumbling block.
>
> In order to make compilation with GUILE 2+ working, we have to move
> away from runtime symbol definition (ie. module-define! calls).
>
> In the code below, it looks like only one of the two definitions in
> the body of my-macro-new takes effect. Is this expected, and if so,
> why?
>
> (defmacro-public my-macro-old (command-and-args . definition)
> (module-define! (current-module) 'x1 "I am X1\n")
> (module-define! (current-module) 'x2 "I am X2\n"))
>
> (defmacro-public my-macro-new (command-and-args . definition)
> `(define p "i am P\n")
> `(define q "i am Q\n"))
>
>
> (my-macro-old 1 2)
> (my-macro-new 1 2)
> (display x1)
> (display x2)
> (display q)
> (display p)
>
>
> thanks,
>
Try the following. Not sure about defmacro but define-syntax must
return a single form.
(defmacro-public my-macro-new (command-and-args . definition)
`(begin
(define p "i am P\n")
(define q "i am Q\n")))
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: definitions in macros?
2020-03-22 19:07 definitions in macros? Han-Wen Nienhuys
2020-03-22 19:16 ` Matt Wette
@ 2020-03-22 21:09 ` David Kastrup
2020-03-23 7:21 ` Han-Wen Nienhuys
1 sibling, 1 reply; 4+ messages in thread
From: David Kastrup @ 2020-03-22 21:09 UTC (permalink / raw)
To: Han-Wen Nienhuys; +Cc: lilypond-devel, Guile Devel
Han-Wen Nienhuys <hanwenn@gmail.com> writes:
> Hi there,
>
> in my quest to get lilypond working with GUILE 2+, I've hit another
> stumbling block.
>
> In order to make compilation with GUILE 2+ working, we have to move
> away from runtime symbol definition (ie. module-define! calls).
>
> In the code below, it looks like only one of the two definitions in
> the body of my-macro-new takes effect. Is this expected, and if so,
> why?
>
> (defmacro-public my-macro-old (command-and-args . definition)
> (module-define! (current-module) 'x1 "I am X1\n")
> (module-define! (current-module) 'x2 "I am X2\n"))
>
> (defmacro-public my-macro-new (command-and-args . definition)
> `(define p "i am P\n")
> `(define q "i am Q\n"))
This is very much expected. The macro body contains two side-effect
free expressions (namely quoted lists) and returns the last one which is
(define q "i am Q\n")
This then gets evaluated at run time, defining q .
You probably wanted something like
`(begin (define p ...) (define q ...))
as your body (and return expression) instead.
> (my-macro-old 1 2)
> (my-macro-new 1 2)
> (display x1)
> (display x2)
> (display q)
> (display p)
>
>
> thanks,
--
David Kastrup
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: definitions in macros?
2020-03-22 21:09 ` David Kastrup
@ 2020-03-23 7:21 ` Han-Wen Nienhuys
0 siblings, 0 replies; 4+ messages in thread
From: Han-Wen Nienhuys @ 2020-03-23 7:21 UTC (permalink / raw)
To: David Kastrup; +Cc: lilypond-devel, Guile Devel
On Sun, Mar 22, 2020 at 10:09 PM David Kastrup <dak@gnu.org> wrote:
> > In the code below, it looks like only one of the two definitions in
> > the body of my-macro-new takes effect. Is this expected, and if so,
> > why?
> >
> > (defmacro-public my-macro-old (command-and-args . definition)
> > (module-define! (current-module) 'x1 "I am X1\n")
> > (module-define! (current-module) 'x2 "I am X2\n"))
> >
> > (defmacro-public my-macro-new (command-and-args . definition)
> > `(define p "i am P\n")
> > `(define q "i am Q\n"))
>
> This is very much expected. The macro body contains two side-effect
> free expressions (namely quoted lists) and returns the last one which is
..
> You probably wanted something like
> `(begin (define p ...) (define q ...))
d'oh! I am an idiot.
Thanks,
--
Han-Wen Nienhuys - hanwenn@gmail.com - http://www.xs4all.nl/~hanwen
^ permalink raw reply [flat|nested] 4+ messages in thread
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2020-03-22 19:07 definitions in macros? Han-Wen Nienhuys
2020-03-22 19:16 ` Matt Wette
2020-03-22 21:09 ` David Kastrup
2020-03-23 7:21 ` Han-Wen Nienhuys
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