Java Platform Module System

Jayaprakash Artanareeswaran jay.a at
Tue May 2 14:12:13 UTC 2017

My previous email showed up blank. So, sending from another email account.

Thanks Stephan for summing it up! And at the risk of repeating myself and Stephan, we are really blocked by these issues and eagerly waiting for the updated spec.

I will also use this opportunity to add one more item that should be taken to completion. This is was already discussed here but not sure there was any conclusion.

Chapter 2 in the JLS [1] describes context-free grammars. The addition to "3.9 Keywords" defines "restricted keywords", which prevent the grammar for ModuleDeclaration from being context-free. This prevents compilers from using common parser generators, since those typically only support context-free grammars. The lexical/syntactic grammar split defined in chapter 2 is not of much use for actual implementations of parsers.
The spec at least needs to point out that the given grammar for ModuleDeclaration is not actually context-free.


[1] <><> (2017-02-22)
----- Original message -----
From: Stephan Herrmann <stephan.herrmann at>
Sent by: "jigsaw-dev" <jigsaw-dev-bounces at>
To: Alex Buckley <alex.buckley at>, jigsaw-dev at
Subject: Re: Java Platform Module System
Date: Tue, May 2, 2017 5:43 PM

Thanks, Alex, for promising improvements in various places of the spec.

I recall several threads on this list ending in you saying "still being
clarified" [1][2]. Are those issues settled by now and just need to be
penned down? Otherwise it would be very helpful just to see the list of
open questions, so we don't bang our heads against walls that are still
subject to change (I'm not speaking about the general "Issue Summary",
but s.t. more focused on JLS and its dependencies in JPMS spec).

Looking forward to an updated spec version, allowing us to double check
if those changes raise any follow-up questions,

[1] <>
[2] <>

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