JEP proposed to target JDK 11: 330: Launch Single-File Source-Code Programs (original) (raw)

Mario Torre neugens at redhat.com
Tue May 22 12:11:57 UTC 2018

On Mon, May 21, 2018 at 5:41 PM, Brian Goetz <brian.goetz at oracle.com> wrote:

Shebang support is an additional feature provided for deploying script-like programs -- which is necessarily at the end of their development phase.

I respectfully disagree, Roman's point that beginning a Java file #! makes it not Java is sound. Also, we can't control how people will write their code, so "at the end of their development phase" may be a very wild assumption that most people may or may not follow. I suspect in fact that it may be quite the opposite, as it's a much faster way to write python styled tools and applications in Java, people my start using it expensively, especially given the rise of all the current features like var and lambdas etc...

It seems rather odd that we are allowing a feature that enables writing invalid Java code that a specific implementation of Java can run but that the JLS specifically forbid. It would be most sensible to amend the specification so that the first two bytes can be 0x23 0x21 to identify a java file that is also a script..

Volker's suggestion may clarify the issues but it won't bypass them, I would rather prefer not to have the confusion in the first place.

Cheers, Mario

-- Mario Torre Associate Manager, Software Engineering Red Hat GmbH <https://www.redhat.com> 9704 A60C B4BE A8B8 0F30 9205 5D7E 4952 3F65 7898

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