'Re: Reasons why Java 7 got me excited about Ant 2'

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List:       ant-dev
Subject:    Re: Reasons why Java 7 got me excited about Ant 2
From:       Nicolas_Lalevée <nicolas.lalevee () hibnet ! org>
Date:       2012-02-26 18:09:44
Message-ID: 88C65E42-7A46-4002-9986-21346BF447D8 () hibnet ! org
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Le 26 févr. 2012 à 18:12, Mansour Al Akeel a écrit :

> Java is widely used and accepted. Scala is functional and it could be more
> suitable for a build system, however, I don't see enough reasons for the
> core to be written with scala or any other language.
> I think it's better to keep it in java, and allow the addition of plugins
> written in other languages the works with JVM (scala, groovy, ... etc).
> 
> This will allow contribution from users experts in java.

+1

And knowing that scala is not stable yet (they break bytecode backward compatibility \
regularly), maintaining an binary API would be quite complicated. Let's stick the \
core of Ant to Java.

Nicolas


> 
> 
> 2012/2/26 wolfgang häfelinger <whaefelinger@gmail.com>
> 
> > Hi there,
> > 
> > how about rewriting Ant 2.0 using Scala? Scala appears to be well
> > suited as a scripting language. Charged with a scripting language, I
> > could write low level macros on the fly.
> > 
> > 
> > // Wolfgang
> > 
> > 
> > On Fri, Feb 17, 2012 at 2:31 AM, Bruce Atherton <bruce@callenish.com>
> > wrote:
> > > I thought I'd expand on why I got so excited about NIO 2.0 and JSR 203 as
> > > well as the other changes in Java 7. I can see I have done a bad job of
> > > selling the benefits of a refactoring for potential volunteers. Reading
> > > through the changes that were introduced in Java 7, it seems to me that
> > Ant
> > > was probably an inspiration for a lot of them.
> > > 
> > > Others come from taking the performance of I/O on Java more seriously.
> > This
> > > has the potential to speed Ant up enormously. Projects like Tim Bray's
> > Wide
> > > Finder 2[1] showcased just how badly Java performed and benchmarks like
> > that
> > > may have been an impetus to focus resources on taking advantage of all
> > the
> > > features of the native filesystems. Unfortunately the results of the
> > project
> > > are lost due to Oracle's acquisition of Sun, but you can still see the
> > > results from the original Wide Finder 1[2] although there isn't even an
> > > attempt to do a Java implementation there. I can tell you from memory
> > that
> > > the final results on WF2 were several C implementations with innovative
> > I/O
> > > using parallel processing at the top, erlang and ruby and scala were up
> > > there, but the fastest Java implementation was in the double digits in
> > the
> > > list as I recall.
> > > 
> > > The basics for file handling in Java 7 are provided by Path and the Paths
> > > Utility class, along with the FileSystemProvider classes. If Ant 2 were
> > > created to make Resource a fundamental element and Path the Resource that
> > > represented something on a file system (native file systems, zip/jar file
> > > systems, and I expect eventually open source projects will add others
> > like
> > > HTTP, FTP, NFS and Samba), I think the LOC count on Ant could be reduced
> > > tremendously. Writing patches would be simplified and contributing to Ant
> > > would have a lower barrier to entry for new people coming in. Path is
> > > immutable which suits Ant well. Path has methods to access elements in a
> > > file path, compare, test, normalize, and relativize paths in the ways
> > that
> > > Ant has code to do. It has all kinds of features for determining
> > > accessibility on the native filesystem and bulk loading file metadata
> > > attributes whereas currently it is done one field at a time. Symbolic
> > link
> > > identification and handling is a core feature. And converting to and from
> > > File objects is trivial.
> > > 
> > > Add to that the new methods on File. There is also a Files utility helper
> > > class. Files covers the most basic tasks in Ant implemented using all the
> > > features of the native filesystem to make them as fast as possible:
> > copying;
> > > deleting; moving; reading file contents; writing; creating directories,
> > file
> > > and links; getting input and output streams. There is also recursion
> > with a
> > > method for walking a file tree that creates a FileVisitor interface
> > > implementation, either default or custom, with 3 phases: previsit
> > directory,
> > > visit file, and postvisit directory. It also provides for a visit file
> > > failed method. At each point you can continue, stop, skip subtree, or
> > skip
> > > other entries in the current directory. Options control whether symlinks
> > are
> > > followed, and cycles are detected.
> > > 
> > > DirectoryStream includes filters like glob, regex, and custom
> > > implementations that could be perfect for implementing Selectors.
> > > DirectoryStream uses less resources and works much better with remote
> > > resources. It also handles directories that are very large much more
> > > efficiently.
> > > 
> > > Error handling throughout is by exception rather than boolean value as
> > it is
> > > now, which I'm sure we all agree is preferable.
> > > 
> > > Then there is the Watch Service which uses the native eventing service if
> > > available, where you can get events in your build when a file is created
> > or
> > > deleted, or when a directory is modified. Would we translate it into
> > > something for BuildListeners? How would we harness it, scheduling a
> > target
> > > and its dependencies when the a watch fired an event?
> > > 
> > > I could keep going  but this is getting rather long. I'll just point out
> > a
> > > few resources from other people that are clearer than I am and have more
> > > detail: The Java 7 feature list[3] is comprehensive but has little on the
> > > impact of features; this Doctor Dobbs post[4] has good code examples for
> > how
> > > NIO 2 could be used by Ant; an article listing "8 things I found most
> > > useful"[5], all of which are relevant to a simplified Ant implementation,
> > > details the NIO 2 changes at #8; interviews with Alan Bateman in text[6],
> > > video[7], and podcast[8] are interesting, as is a JavaOne 2011 slide
> > > show[9];  Leandro Pezzente sent me a link[10] (thanks, Leandro) that
> > lists
> > > some of the other changes to Java 7 to think about, although it only
> > > mentions the file system changes that JSR 203 introduces in passing.
> > > 
> > > [1] http://www.tbray.org/ongoing/When/200x/2008/05/01/Wide-Finder-2
> > > [2] http://www.tbray.org/ongoing/When/200x/2007/10/30/WF-Results
> > > [3] http://openjdk.java.net/projects/jdk7/features/#f250
> > > [4] http://drdobbs.com/blogs/jvm/231600403
> > > [5] http://jaxenter.com/java-7-the-top-8-features-37156.html
> > > [6] http://www.artima.com/lejava/articles/more_new_io.html
> > > [7] http://www.youtube.com/watch?v=yNRS1ssLPdQ
> > > [8]
> > > 
> > https://blogs.oracle.com/javaspotlight/entry/java_spotlight_episode_59_alan
> > > [9] http://openjdk.java.net/projects/nio/presentations/TS-5052.pdf
> > > [10]
> > > 
> > http://marxsoftware.blogspot.com/2011/03/jdk-7-new-interfaces-classes-enums-and.html
> > 
> > > 
> > > 
> > > ---------------------------------------------------------------------
> > > To unsubscribe, e-mail: dev-unsubscribe@ant.apache.org
> > > For additional commands, e-mail: dev-help@ant.apache.org
> > > 
> > 
> > 
> > 
> > --
> > Wolfgang Häfelinger
> > 
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: dev-unsubscribe@ant.apache.org
> > For additional commands, e-mail: dev-help@ant.apache.org
> > 
> > 


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