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Converting an SXML file to a list
Posted: Tue Jul 11, 2006 8:57 am
by cormullion
Say I have an SXML file:
Code: Select all
((rss
(@
(version "0.92"))
(channel
(docs "http://backend.userland.com/rss092")
(title "newLISP Fan Club")
(link "http://www.alh.net/newlisp/phpbb/")
(description "Friends and Fans of newLISP ")
(managingEditor "dooright101@yahoo.com")
(webMaster "dooright101@yahoo.com")
(lastBuildDate "Mon, 10 Jul 2006 22:40:58 GMT")
(item
...
How can I make this into a list?
(I think this might be an easy question but when you don't know the answer, every question seems hard... :-)
Posted: Tue Jul 11, 2006 9:09 am
by m i c h a e l
cormullion wrote:How can I make this into a list?
Code: Select all
(list (rss
(@
(version "0.92"))
(channel
(docs "http://backend.userland.com/rss092")
...
Sorry, bad joke ;-)
m i c h a e l
Posted: Tue Jul 11, 2006 9:11 am
by cormullion
Well, funnily enough I did try that (using read-file)...:-) I got a list containing one very large string...
Posted: Tue Jul 11, 2006 1:04 pm
by Lutz
It is already a list. I assume you want to find certain things in it?
I have assigned the list to a variable called RSS to handle it better:
Code: Select all
(set 'RSS '((rss
(@
(version "0.92"))
(channel
(docs "http://backend.userland.com/rss092")
(title "newLISP Fan Club")
(link "http://www.alh.net/newlisp/phpbb/")
(description "Friends and Fans of newLISP ")
(managingEditor "dooright101@yahoo.com")
(webMaster "dooright101@yahoo.com")
(lastBuildDate "Mon, 10 Jul 2006 22:40:58 GMT") ))))
;use ref to find the indices of something:
> (ref 'channel RSS)
(0 2 0)
>
; try it
> (RSS 0 2 0)
channel
>
; strip of the last index number to extract the channel members
> (RSS 0 2)
(channel (docs "http://backend.userland.com/rss092") (title "newLISP Fan Club")
(link "http://www.alh.net/newlisp/phpbb/")
(description "Friends and Fans of newLISP ")
(managingEditor "dooright101@yahoo.com")
(webMaster "dooright101@yahoo.com")
(lastBuildDate "Mon, 10 Jul 2006 22:40:58 GMT"))
; taking the rest of it gives you just the channel members
> (set 'CHN (1 (RSS 0 2)))
((docs "http://backend.userland.com/rss092") (title "newLISP Fan Club")
(link "http://www.alh.net/newlisp/phpbb/")
(description "Friends and Fans of newLISP ")
(managingEditor "dooright101@yahoo.com")
(webMaster "dooright101@yahoo.com")
(lastBuildDate "Mon, 10 Jul 2006 22:40:58 GMT"))
>
; on this you could use assoc to find something:
> (assoc 'link CHN)
(link "http://www.alh.net/newlisp/phpbb/")
> (assoc 'webMaster CHN)
(webMaster "dooright101@yahoo.com")
>
Lutz
Posted: Tue Jul 11, 2006 1:08 pm
by cormullion
Hi Lutz! The thing I can't do is this:
since the ((rss ... stuff is in a file. For now I'm doing what you're doing, and copying the SXML into a (set ... expression. But I couldn't work out how to get a file containing this into a symbol...
Posted: Tue Jul 11, 2006 1:14 pm
by Lutz
lets assume this in your file:
Code: Select all
;; file rss-info
((rss (@ (version "0.92")) (channel (docs "http://backend.userland.com/rss092")
(title "newLISP Fan Club")
(link "http://www.alh.net/newlisp/phpbb/")
(description "Friends and Fans of newLISP ")
(managingEditor "dooright101@yahoo.com")
(webMaster "dooright101@yahoo.com")
(lastBuildDate "Mon, 10 Jul 2006 22:40:58 GMT"))))
;; eof
Do the following to get it all in to the variable RSS:
Code: Select all
> (set 'RSS (eval-string (append "'" (read-file "rss-info"))))
((rss (@ (version "0.92")) (channel (docs "http://backend.userland.com/rss092")
(title "newLISP Fan Club")
(link "http://www.alh.net/newlisp/phpbb/")
(description "Friends and Fans of newLISP ")
(managingEditor "dooright101@yahoo.com")
(webMaster "dooright101@yahoo.com")
(lastBuildDate "Mon, 10 Jul 2006 22:40:58 GMT"))))
Lutz
Posted: Tue Jul 11, 2006 1:37 pm
by cormullion
Lutz wrote:Code: Select all
> (set 'RSS (eval-string (append "'" (read-file "rss-info"))))
That's the one! I feel better now, because I never tried that ... :-)
This works for the short example file that you gave. I am trying to make it work with a longer SXML file now - assuming there's no size limit for eval-string, it might just be some formatting that's gone adrift...
Anyway, thanks, Lutz!