lowdown: markdown->sxml produces unnormalised SXML

[Norman Gray]

% csi

CHICKEN
(c) 2008-2015, The CHICKEN Team
(c) 2000-2007, Felix L. Winkelmann
Version 4.10.0 (rev b259631)
macosx-unix-clang-x86-64 [ 64bit manyargs dload ptables ]
compiled 2015-08-04 on yves.more-magic.net (Linux)

#;1> (use lowdown sxpath)
; loading /Data/tools/chicken-4.10.0/lib/chicken/7/lowdown.import.so ...
[...]
#;2> (define testdoc "Title\n=====\n\n  * [link](uri)\n")
#;3> (define sx-test (with-input-from-string testdoc (lambda () (markdown->sxml (current-input-port)))))
#;4> sx-test
((h1 ("Title")) (ul (li ((a (@ (href "uri")) "link")))))
#;5> ((sxpath '(// a)) sx-test)
()
#;6> (define (tidy-sxml sx)
      (cond ((not (list? sx)) sx)
            ((and (= (length sx) 1)
                  (list? (car sx)))
             ;; turn ((node ...)) into (node ...)
             (tidy-sxml (car sx)))
            (else (map tidy-sxml sx))))
#;7> ((sxpath '(// a)) (tidy-sxml sx-test))
((a (@ (href "uri")) "link"))
#;8> 

I think the parsed sx-test is not invalid, but it does appear to be
sufficiently unnormalised that it confuses sxpath.
See ​http://okmij.org/ftp/Scheme/SXML.html#Normalized%20SXML

The function tidy-sxml works in this case, but is probably too simple-minded to work in general.