Re: and-let* is not composable?
2013/9/10 Ian Price > > I have a few notes unrelated to those I've already mentioned in the > thread. > > 1. Guile already has curried definitions in (ice-9 curried-definitions) > > Yes, but those are completely different. I wouldn't call "define-curried" a curried definition, but a definition of a curried macro for generating procedures. > 2. By turning your functions definitions into a macro, you've lost the > ability to use them in a first class manner. > > That's not entirely true. I just need an extra pair of parentheses to do so. The semantics is certainly different than the one of Guile's curried definitions, but that's fine. > 3. I would strongly recommend _not_ using define-macro, and even more > so, not mixing define-macro and syntax-rules in a macro. Syntax-case is > as powerful as defmacro, and in most practical cases, about as much > writing. > Well, while syntax-rules macros are quite easy to understand (at least from the user's point of view), although sometimes a little tricky, the syntax-case system I find still too difficult to use. define-macro, on the other hand, is very easy to explain even to beginner programmers, although the resulting macros are much more difficult to analyse. The main problem with syntax-rules/syntax-case macros is the treatment of ellipses, which makes it difficult to create macros that create macros. Still, I didn't post to comp.lang.scheme for no reason :) 4. What your macro does is not currying, it is partial > application. Those are different things. Currying refers to the process > of turning a function of n arguments into an n-nested set of 1 argument > functions. Partial application is, well, not supplying all the arguments > to a function. You can have partial application without currying, as > your macro shows. > OK, you got me here. But it's still difficult for me to come up with a good name for that macro (and if so, the Guile's curried definitions are not curried either, at least in general: because you can (define ((f a b) c d) ...), getting a chain of 2-argument functions) Thanks, M.
Re: and-let* is not composable?
Panicz Maciej Godek writes: > That's not entirely true. I just need an extra pair of parentheses > to do so. The semantics is certainly different than the one of > Guile's curried definitions, but that's fine. An identifier macro would be even better, but it's still not first class. > Well, while syntax-rules macros are quite easy to understand > (at least from the user's point of view), although sometimes a little > tricky, the syntax-case system I find still too difficult to use. > define-macro, on the other hand, is very easy to explain > even to beginner programmers, although the resulting macros > are much more difficult to analyse. If you, or the other people who are confused by syntax-case, can point to the parts of the manual that confuse you, so we can clear them up, I think we'd all appreciate it. Fundamentally, syntax-case shouldn't be harder to use than define-macro 99% of the time, if you remember - macros are functions from "syntax-objects" to syntax-objects - syntax-objects are smart symbols - syntax->datum to remove the smartness - datum->syntax is for when you want to break hygiene (but syntax parameters are better where applicable) - use quasisyntax to construct lists of syntax-objects instead of quasiquote to construct lists of symbols. > The main problem with syntax-rules/syntax-case macros is > the treatment of ellipses, which makes it difficult to create > macros that create macros. You can expand into ellipses with (... ...), it's ugly, but it's there. > with a good name for that macro (and if so, the Guile's curried > definitions are not curried either, at least in general: because > you can (define ((f a b) c d) ...), getting a chain of 2-argument > functions) Indeed, I wasn't sure whether or not I should have mentioned it, but I was told this is the "correct" name for that feature on comp.lang.scheme a while back. I think it might have been Will Clinger, but I'd need to double check. -- Ian Price -- shift-reset.com "Programming is like pinball. The reward for doing it well is the opportunity to do it again" - from "The Wizardy Compiled"
Doctest for guile
Hello! I am glad to offer implementation of doctest in Guile --- way to declare and check tests in function docstring. In most simple way, if in docstring you write following: +++ (foo 1 2 3) --- 6 doctests will check if it is really so. I belive it encourage writing more modular, generic and pure function. Also, such tests helps to understand function behavior on corner cases. This is just proof-of-concept, that offer following: + test of multiple values + testing of not-exported functions. You can just download attached archive(I belive it small enough to not bother with ftp) and do following: $ tar xf doctest.tar.gz $ cd doctest $ export GUILE_LOAD_PATH=$PWD $ guile doctest.scm '(foo)' ## Two successful tests, one failure ## If no modules specified, doctest tests itself $ guile doctest.scm But much more is todo: + contollable verbosity + exit status on failed tests + shortcut for predicates + it crashes on input like this: +++ (foo 1 2 3 --- 6 + there is no way to say that test should throw + Your ideas? I it will be found useful enough, I will gladly work on patch to integrate doctest in Guile guild script. doctest.tar.gz Description: Tarball of doctest sources -- Best regards, Dmitry Bogatov , Free Software supporter and netiquette guardian. git clone git://kaction.name/rc-files.git --depth 1 GPG: 54B7F00D Html mail and proprietary format attachments are forwarded to /dev/null. pgph69FiC4WS4.pgp Description: PGP signature
Re: Problem with wide characters on upgrading to guile 2.x
On Sat, 2013-09-07 at 11:07 +0200, Andy Wingo wrote:
> On Mon 02 Sep 2013 10:48, Richard Shann writes:
>
> > On Thu, 2013-08-22 at 12:14 -0700, Mike Gran wrote:
> >> >> 2. In the inner_main of your scm_with_guile call,
> >>
> >> >> try calling scm_setlocale. Maybe something like this?
> >> >> (This shouldn't make a difference, I think.
> >> >> But, if it does, it says something interesting.)
> >> >>
> >> >> scm_setlocale( scm_variable_ref(scm_c_lookup("LC_ALL")),
> >> > scm_from_locale_string("") );
> >> >
> >> >> If that actually works, lemme know.
[...]
> >
> > ERROR: In procedure catch-closure:
> > ERROR: In procedure setlocale: Invalid argument
> > 8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><
>
> const char prog[] =
> "(catch #t
> (lambda () (setlocale LC_ALL \"\"))
> (lambda _
>(display \"Locale not supported by the C library.
> Falling back to default \\\"C\\\" locale.\\n\"
> (current-error-port";
> scm_c_eval_string (prog);
>
> Andy
Thank you! That does nicely.
Richard
pretty-print for 1+
Using guile 2.0.9 and the ice-9 pretty-print module, when I apply:
(pretty-print '(1+ 1))
I get:
(#{1+}# 1)
I was expecting:
(1+ 1)
Is this an issue with pretty-print or should I adjust my expectation?
