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https://issues.apache.org/jira/browse/JEXL-113?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13062391#comment-13062391
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Henri Biestro commented on JEXL-113:
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Hi Max,
So, your functional need is extracting which variables are used to evaluate a
script. I've had the same need for a while.
So maybe an 'extractDependencies' method could be more useful than fumbling
with the 'dot' operator behavior.
Its signature could be: Set<List<String>> JexlEngine.extractDependencies(Script
script). Each entry in the returned set would be the list of constant 'names'
used in references aka dot or bracket expressions.
Would this be adequate ?
Cheers
Henri
PS/ thanks for the positive reinforcement :-)
> Dot notation behaves unexpectedly with null values
> --------------------------------------------------
>
> Key: JEXL-113
> URL: https://issues.apache.org/jira/browse/JEXL-113
> Project: Commons JEXL
> Issue Type: Bug
> Affects Versions: 2.0.1
> Environment: JDK 1.6
> Reporter: Max Tardiveau
>
> When a variable of the form a.b is evaluated, the context is asked first for
> the value of a. That value is then asked for the value of b.
> So far, so good: this is exactly what you'd expect from the dot operator.
> But if the value of b is null, the context is then asked for the value of
> a.b, in other words the dot operator is ignored and "a.b" is considered to be
> a single variable.
> This is at best confusing. Granted, this can be avoided with the a['b']
> notation, but that's clumsy.
> I assume this is an attempt to support both the dot operator and ant-style
> variables. I don't think you can have both and remain sane.
> Suggestion: either document this behavior, or make it an option. My vote
> would be to just use the value returned, even if it's null. Either dot is an
> operator, or it's not. Perhaps make that configurable?
> Thanks!
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