What is a language construct? (was Re: Comment on state of Project Jigsaw)

[Alex Buckley]

On 12/21/2011 2:39 PM, Rémi Forax wrote:
> Java is a programming languages with several sources files
> and jigsaw introduces a rule to find the module declaration
> from a source file. This rule used a convention instead of a
> declaration i.e. you don't have to edit all class files
> to declare that they are part of a module but you have to use
> a precise source layout.
>
> If this layout is defined in the language spec so I don't see the problem.

As Mark said, a module declaration is just another kind of declaration 
within a compilation unit. The JLS has never made normative statements 
about the physical form or layout of compilation units. (Nor, for that 
matter, has the JVM Spec with regard to class files).

A compiler for the Java language is free to make up rules for the 
placement on a file system of files that represent compilation units. 
The file system placement of a compilation unit containing a module 
declaration should no more be specified in the JLS than the placement of 
a compilation unit containing a type declaration.

I am still curious to know how Neal would integrate statements or 
declarations into the Java language that determine the visibility of 
types ("observability", in JLS terms) for code within the scope of the 
statements or declarations.

Alex