[
https://issues.apache.org/jira/browse/JEXL-390?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17651338#comment-17651338
]
Henri Biestro commented on JEXL-390:
------------------------------------
You are absolutely correct. One way to fool-proof it ( pragmas must occur
before any statement) and maintain compatibility (and choice) would be to
introduce a feature flag (much like operator names).
> Pragmas should not be statements
> --------------------------------
>
> Key: JEXL-390
> URL: https://issues.apache.org/jira/browse/JEXL-390
> Project: Commons JEXL
> Issue Type: Improvement
> Affects Versions: 3.2.1
> Reporter: Dmitri Blinov
> Assignee: Henri Biestro
> Priority: Minor
> Fix For: 3.3
>
>
> In Jexl pragmas are treated as statements syntactically, but do not find
> their way to AST tree and this leads to strange bugs like in the following
> example
> {code}
> @Test
> public void testBadPragmas() throws Exception {
> final JexlEngine jexl = new
> JexlBuilder().cache(1024).debug(true).create();
> final JexlScript script = jexl.createScript("if (true) #pragma one
> 42");
> JexlContext jc = new MapContext();
> final Object result = script.execute(jc);
> debuggerCheck(jexl);
> }
> {code}
> While this partucular bug can be trivially fixed, in fact the whole idea to
> allow putting pragmas for example inside a loop or inside if-branch is a
> strange language design (I'm not aware of examples in other languages) as it
> gives false idea of the pragma being controlled by script execution logic.
> If there's no reason or use case to keep this design as is, my proposal is to
> make a grammar change and allow pragmas to be declared only at the top of the
> script. Another point to change current pragma implementation is that pragmas
> can not be used with expressions, e.g. no way to specify standard options /
> imports.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
