Like some people mentioned, you can use a parsing library, but often
times I don't think that's necessary if you are just creating a DSL.
There are a couple of other strategies.
One is you can use a series of nested macros that expand into a data
structure. In this way your DSL will sort of auto-transform into a
nested data structure that you can then just operate on like regular
data. Here's what I mean, using a mini database DSL as an example:
(defmacro table [name & body]
`{:type :table
:name (str (quote ~name))
:cols [...@body]})
(defmacro col [name type]
`{:type :col
:name (str (quote ~name))
:data-type ~type})
; Allowing for specifications like this:
(table users
(col email :string)
(col password :string))
(Note: You can run this code to see the data structure it produces...)
Alternatively, if you want to get rid of parenthesis or introduce new
semantics, then you'll need to process the tokens yourself with some
logic. At a larger scale this is better done with a parser, but if
you just need to support a special keyword here or there, it's pretty
easy to include some simple logic in a macro to look at a symbol and
do something different depending on what it is. In general I try to
keep the semantics inside normal function definitions though, and just
use macros for restructuring.
-Jeff
On Jul 8, 8:52 pm, Nicolas Oury <nicolas.o...@gmail.com> wrote:
> Dear all,
>
> I am trying to write a small Domain Specific Language using macro, and I
> want the syntax of the args of the macro to be somehow "parsed" and
> transformed.
>
> So, I have two questions:
>
> - Does anybody else does that? (except the infix calculus) Is there a
> generic method for doing it? Or even better a library?
> - I want to report syntax error from my macro expansion. Is there a way to
> get the line (or even better the line/file and character) of the usage of a
> macro being expanded?
> That way I could have helpful error message....
>
> Best regards,
>
> Nicolas.
--
You received this message because you are subscribed to the Google
Groups "Clojure" group.
To post to this group, send email to clojure@googlegroups.com
Note that posts from new members are moderated - please be patient with your
first post.
To unsubscribe from this group, send email to
clojure+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/clojure?hl=en
