[antlr-interest] How to report bugs ?

Randall R Schulz rschulz at sonic.net
Sat Mar 24 07:55:30 PDT 2007


On Saturday 24 March 2007 03:12, Martin Probst wrote:
> Hi,
> > The use of File.separator I think this is a constant depending on
> > the platform. So if you compile this on a Windows box, it won't
> > work on a *nix box.
> >
> > The only evidence I have is that the released jar with Antlrworks
> > didn't work on my Mac. I recompiled the antlr jar and it worked
> > fine.
> File.separator is a constant in the File class, but Java is a late-
> binding language so this constant won't be inlined until runtime. So
> this should not be an issue on UNIX or Windows systems. And
> ANTLRWorks works for me on my Mac :-) Did you download the .app
> package?

Actually, this is not true for fields that are declared "static final". 
In this case, the compiler inlines the value it finds when compiling.

There's a passage in the language specification (see sec. 13.4.9 of "The 
Java Language Specification, 3rd Edition", pg. 349) suggesting that 
for "constants" of the sort represented by these fields of class File 
that a static accessor method be used.

Presumably the authors of File hadn't considered these subtleties way 
back when they originally implemented it and established the API for 
that class. The really should add the static methods.

Also, if you look at the description of those methods, you'll see 
they're initialized from system properties, so code that needs to use 
the constants specific to the platform on which they're running can 
access those system properties. To wit (from 


public static final char separatorChar

    The system-dependent default name-separator character. This field is 
initialized to contain the first character of the value of the system 
property file.separator. On UNIX systems the value of this field 
is '/'; on Microsoft Windows systems it is '\\'.

    See Also:


public static final String separator

    The system-dependent default name-separator character, represented 
as a string for convenience. This string contains a single character, 
namely separatorChar.

Lastly, the Macintosh (at least Mac OS X) is a Unix system and uses the 
same file and path separator characters as does Linux, Solaris and 
other POSIX-compliant systems. So I'm not sure why the OP had problems 

> Regards,
> Martin

Randall Schulz

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