Two minutes ago, Jon Rafkind wrote:
>
> My issue is that first I try @{foo} and get the error "expected a
> procedure, given a string". At which point I remember kevin telling
> me off-hand how you (eli) had a trick to deal with these situations,
> which was to put string-append between the @ and {.
It's not really a trick. What if you want to do something else:
(define foo 123)
@string-append{blah @foo blah}
this reads as
(string-append "blah " 123 " blah")
Obviously, `list' won't work in all cases too, since you might want a
string.
Instead, things are kept very simple -- and very *uniform*: both the
"command part" (following the `@') and the "datums part" (inside `[]')
are put in a list, before the rest of the actual text. Since the
command part is optional, you can omit it, but then
@{foo bar baz}
reads as ("foo bar baz")
Another exmaple:
@[emph]{blah}
reads as (emph "blah") which is the same as
@emph{blah}
If you want a cheap way to have a list of text, you could use quote
(again, uniformity is top priority, which makes these things fall off
for free):
'{for bar baz}
but there's no similar way to get a single string, because of the
"interpolation" feature. (Not really interpolation, but close in
spirit.)
> Could @{ as a special case do string-append for me?
BTW, you could still do it in your language:
-> ,r scribble/reader
-> (read-syntax)
@{foo}
#<syntax::34 ("foo")>
-> (syntax-property ^ 'scribble)
'(form #f 1)
having a scribble property that starts with `form' identifies a form,
and the #f identifies the missing command part. (I don't remember
what's 1, but that should be easy to find.)
--
((lambda (x) (x x)) (lambda (x) (x x))) Eli Barzilay:
http://barzilay.org/ Maze is Life!
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