[jira] [Commented] (JEXL-229) Introduce new syntax for class literals: Class and Type
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https://issues.apache.org/jira/browse/JEXL-229?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16182695#comment-16182695
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Dmitri Blinov commented on JEXL-229:
I have found another solution to this problem. I have adjusted the
{{JexlContext}} class to resolve ant-ish style context properties like for
example {{java.lang.Integer}} to the instances of corresponding
{{Class}} so it is now as easy to address {{Class}}
objects as to write
{code}if (obj =~ java.util.Map){code}
Furthermore, I have added a property resolver for {{Class}} objects to
return static class members, like for example {code}var one =
java.math.BigInteger.ONE{code} This also allowed me to access {{Class}}
objects for primitive types, since they are referenced via {{TYPE}} static
member of corresponding boxed type, like the following
{code}java.lang.Integer.TYPE{code} I think I have achieved what I was aiming
at, a clean solution without functors and need to use type names as strings. So
I think it is better now to close this issue.
> Introduce new syntax for class literals: Class and Type
> -
>
> Key: JEXL-229
> URL: https://issues.apache.org/jira/browse/JEXL-229
> Project: Commons JEXL
> Issue Type: New Feature
>Affects Versions: 3.1
>Reporter: Dmitri Blinov
>Priority: Minor
>
> For the purpose of type checking in jexl, It whould be convenient to have
> some simple syntax for referring to class types, like Class or
> Type. Literal Class should refer to general classes, and literal
> Type should refer to primitive type classes. For literals Class it
> could be possible to specify partal class name, which should resolve to
> classes in basic packages like java.lang and java.util, for example.
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[jira] [Commented] (JEXL-229) Introduce new syntax for class literals: Class and Type
[
https://issues.apache.org/jira/browse/JEXL-229?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16064557#comment-16064557
]
Dmitri Blinov commented on JEXL-229:
The difference between a dedicated literal, like Class, and a functor
classp("String") in my view is as the difference between literal
{code}
1234.33B
{code}
and its functional equivalent
{code}
new ("java.math.BigDecimal", "1234.33")
{code}
the readability, compactness and parse-time checks, which is good for Q
The use case I'm after is to get away from now existing functors like
{{isMap()}}, {{isCollection()}} {{isSet()}} and to come to more generic type
checking. I have overloaded the {{=~}} operator to be used with right-hand
{{Class}} instances by calling either Class.isInstance() for objects or
Class.isAssignableFrom() for other Classes, for example
{code}
if (obj =~ klass)
{code}
so I think we can get along without introducing {{instanceof}} operator, but
for the types, as they are very basic Java elements for scripting, like
primitives, IMHO, it would be desirable to have a special language construct.
> Introduce new syntax for class literals: Class and Type
> -
>
> Key: JEXL-229
> URL: https://issues.apache.org/jira/browse/JEXL-229
> Project: Commons JEXL
> Issue Type: New Feature
>Affects Versions: 3.1
>Reporter: Dmitri Blinov
>Priority: Minor
>
> For the purpose of type checking in jexl, It whould be convenient to have
> some simple syntax for referring to class types, like Class or
> Type. Literal Class should refer to general classes, and literal
> Type should refer to primitive type classes. For literals Class it
> could be possible to specify partal class name, which should resolve to
> classes in basic packages like java.lang and java.util, for example.
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[jira] [Commented] (JEXL-229) Introduce new syntax for class literals: Class and Type
[ https://issues.apache.org/jira/browse/JEXL-229?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16062958#comment-16062958 ] Henri Biestro commented on JEXL-229: A set of use cases is missing. However and in general, I suspect a new syntax is not warranted. Can you give produce an example/test using a classp(...) or typep(...) function/functor in a namespace so what you're after is made clear? > Introduce new syntax for class literals: Class and Type > - > > Key: JEXL-229 > URL: https://issues.apache.org/jira/browse/JEXL-229 > Project: Commons JEXL > Issue Type: New Feature >Affects Versions: 3.1 >Reporter: Dmitri Blinov >Priority: Minor > > For the purpose of type checking in jexl, It whould be convenient to have > some simple syntax for referring to class types, like Class or > Type. Literal Class should refer to general classes, and literal > Type should refer to primitive type classes. For literals Class it > could be possible to specify partal class name, which should resolve to > classes in basic packages like java.lang and java.util, for example. -- This message was sent by Atlassian JIRA (v6.4.14#64029)
