Re: Looking for help. Implementing a XML validation engine in JavaScript.
[email protected] (Henry S. Thompson)
| Newsgroups | gmane.text.xml.schema.devel,gmane.comp.web.dom.general |
|---|---|
| Message-ID | <[email protected]> |
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Casey Jordan writes:
> <sequence>
> <element ref="e1"/>
> <choice minOccurs="2">
> <element ref="e2" maxOccurs="2"/>
> <element ref="e3"/>
> </choice>
> <element ref="e4"/>
> </sequence>
>
> This can be seen as a regular expression e1( e2{1,2} | e3 ){2,2} e4. My
> greedy algorithm cannot validate this correctly.
>
> Assuming input like <e1/><e2/><e2/><e4/>
This problem is discussed in [1], which asserts that you need to fall
back to pseudo-parallel or backtracking in such cases. The Python
code in XSV, which I pointed you to yesterday, implements this
fallback.
ht
- --
Henry S. Thompson, School of Informatics, University of Edinburgh
10 Crichton Street, Edinburgh EH8 9AB, SCOTLAND -- (44) 131 650-4440
Fax: (44) 131 651-1426, e-mail: [email protected]
URL: http://www.ltg.ed.ac.uk/~ht/
[mail from me _always_ has a .sig like this -- mail without it is forged spam]
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