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From "Dmitri Blinov (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (JEXL-271) Hoisted variable is lost when currying lambda
Date Mon, 10 Sep 2018 15:15:00 GMT

    [ https://issues.apache.org/jira/browse/JEXL-271?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16609371#comment-16609371
] 

Dmitri Blinov commented on JEXL-271:
------------------------------------

Since we modified the Interpreter.java here, can you also look at {{Interpreter.interpret()}}
method, there is a possibility of incorrect {{ThreadLocal}} handling. First there is a {{cancelCheck(node)}}
call in {{try}} block before threadlocal initialization, and since {{cancelCheck()}}can throw
exception we may eventually end up in restoring wrong values in {{finally}} section later
on. Moreover, within {{finally}} section we try to call {{closiIfSupported()}} for each functor,
and who knows, the corresponding {{close()}} method may also throw an exception, like {{java.io.IOException}},
so we again can skip to restore the correct threadlocal values. ThreadLocals are very important
in container environment

> Hoisted variable is lost when currying lambda
> ---------------------------------------------
>
>                 Key: JEXL-271
>                 URL: https://issues.apache.org/jira/browse/JEXL-271
>             Project: Commons JEXL
>          Issue Type: Bug
>    Affects Versions: 3.1
>            Reporter: Dmitri Blinov
>            Assignee: Henri Biestro
>            Priority: Major
>             Fix For: 3.2
>
>
> I have noticed that when I curry the lambda that contains hoisted variable, then binding
to that variable is lost when I call curried lambda. The following test case illustrates the
problem
> {code}
>     @Test
>     public void testCurry4() throws Exception {
>         JexlEngine jexl = new JexlBuilder().strict(false).create();
>         JexlScript base = jexl.createScript("var base = 2; var sum = (x, y, z)->{
base + x + y + z }; var y = sum.curry(1); y(2,3)");
>         Object result = base.execute(null);
>         Assert.assertEquals(8, result);
>     }
> {code}
> To put it another way, the following script returns {{2}} when it should return {{0}};
> {code}var base = 2; var sum = (x, y, z)->{ base + x + y + z }; var y = sum.curry(1);
sum(1, 2, 3) - y(2,3){code}



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