On Sun 26 Jun 2016 23:06, Andy Wingo <wi...@pobox.com> writes:
> On Tue 17 Nov 2015 09:27, Koz Ross <koz.r...@retro-freedom.nz> writes:
>
>> I have the following file, called foo.scm:
>>
>> (define-module (koz foo)
>> #:use-module (srfi srfi-9))
>>
>> (define-public (make-empty-bar)
>> (make-bar #f))
>>
>> (define-record-type <bar>
>> (make-bar open)
>> bar?
>> (open bar-open set-bar-open!))
>
>> Would it be possible for the error message in this case to be a bit
>> more helpful? Even better, would it be possible to not make this an
>> issue when compiling?
>
> It would be possible to make the scope of make-bar be the whole file.
> In theory it should work I guess, given this news entry from 2.0.1:
>
> ** `begin' expands macros in its body before other expressions
Apparently the reason this doesn't work in Guile right now is that the
compiler currently reads and compiles one Scheme expression at a time,
then stitches them together on the Tree-IL level. Incidentally,
`primitive-load' works in the same way for the interpreter: it reads and
eval's single expressions in a loop. We could change this to have Guile
read the whole file and pass it all to the expander at once, within a
`begin'. This has some user-visible changes though:
* if evaluating an expression throws an error, primitive-load doesn't
read the following expressions and so doesn't detect syntax errors;
try a file like this:
(error "what")
)
With the interpreter (primitive-load) you will get the "what" error,
not a syntax error. (Yes the unclosed paren hurts my eyeballs but I
wanted to demonstrate a syntax error. Here's a matching paren:
")".)
* Procedural macros won't be able to use bindings defined previously
in the file unless they are eval-whenned. Of course this already
breaks in the compiler, but it succeeds in the interpreter.
Maybe now is a good time to do this though, in 2.2. Ludovic, Mark:
thoughts?
Andy
