[ 
https://issues.apache.org/jira/browse/DAFFODIL-2692?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17530823#comment-17530823
 ] 

Mike Beckerle commented on DAFFODIL-2692:
-----------------------------------------

DFDL Workgroup email discussion it was suggested that rather than a new 
lengthKind, instead a policy/mode property be added which specifies the 
lengthKind 'pattern' behavior when the pattern does not match. E.g., 

dfdlx:lengthKindPatternNoMatchPolicy="zeroLength|error" where the default for 
compatiblity with DFDL v1.0 would be zeroLength. 

 

> Add lengthKind 'valuePattern' which uses regex to match allowed data values
> ---------------------------------------------------------------------------
>
>                 Key: DAFFODIL-2692
>                 URL: https://issues.apache.org/jira/browse/DAFFODIL-2692
>             Project: Daffodil
>          Issue Type: New Feature
>          Components: Back End, Front End
>    Affects Versions: 3.3.0
>            Reporter: Mike Beckerle
>            Priority: Major
>
> Existing dfdl:lengthKind 'pattern' uses the pattern to determine the length. 
> No match means length 0.
> People want to use regular expression (or regex) matches differently from 
> this. They want to specify the allowed data patterns, with no match meaning 
> parse error. 
> This should be added as a dfdlx experimental feature to develop experience 
> with it. 
> A few design issues: we need to decide if this pattern includes nil values in 
> its syntax, or if those get added as allowed value patterns automatically. It 
> is simpler if we define this to require that the regex pattern specify all 
> possible data patterns that are accepted, whether they become nilled 
> elements, or elements with values. That, however, requires one to redundantly 
> express the dfdl:nilValue information.
> There may also be an interaction with properties like 
> dfdl:emptyValueDelimiterPolicy and the empty representation. I.e., does the 
> pattern have to allow for a zero-length successful match in order for the 
> data to be zero-length?
>  
>  
>  
>  



--
This message was sent by Atlassian Jira
(v8.20.7#820007)

Reply via email to