So let's say, perhaps, we don't generate a BOM, unless asked
specifically... but not with new methods, but with new parameters to such
methods. In addition to specifying a charset, we could also pass a boolean
saying we want a BOM to be generated (false by default, needs to be
specified as true if BOM wanted) ?
2015-06-09 21:47 GMT+02:00 Keegan Witt <keeganw...@gmail.com>:
> I get that -- and I wish JDK did the same. But what bothers me most about
> the current state is that sometimes it's transparent, sometimes it's not --
> depending on how it was invoked. And while we could fix the new instance
> usage too with metaClass, that could lead to weird inconsistencies when
> Groovy is invoked from Java.
>
> I really think most users would not expect these two usages to behave
> differently. I think most would expect the difference to be stylistic
> only. So as much as it pains me to say this, I think it's better not to
> violate the principle of least surprise, and remain consistent across all
> styles of invocation with Java's poor life choices.
>
> But maybe the friendlier APIs can be moved into new methods, such as new
> BomAwareWriter() / WithBomAwareWriter{} What do you think? If we did
> that, I guess it'd be consistent to do the same for the readers as well.
>
> -Keegan
>
> On Tue, Jun 9, 2015 at 3:22 PM, Guillaume Laforge <glafo...@gmail.com>
> wrote:
>
>>
>> 2015-06-09 18:57 GMT+02:00 Keegan Witt <keeganw...@gmail.com>:
>>
>>> I created PR 37 <https://github.com/apache/incubator-groovy/pull/37> to
>>> correct the JavaDoc I mentioned (as well as to document the existing
>>> behavior for the non-NIO methods).
>>>
>>> Java doesn't eat the BOM, but this is a problem Java folks are used to
>>> dealing with, and why things like Apache Common-IO's BOMInputStream
>>> <https://commons.apache.org/proper/commons-io/apidocs/org/apache/commons/io/input/BOMInputStream.html>
>>> exist.
>>>
>>
>> That's also why I made Groovy eat the BOM too, so that it's transparent
>> to our users :-)
>> But that was a long time ago since I worked on those parts of the
>> codebase, and it's been refactored quite a bit (by Jim for example).
>>
>>
>>>
>>> -Keegan
>>>
>>> On Tue, Jun 9, 2015 at 11:33 AM, Guillaume Laforge <glafo...@gmail.com>
>>> wrote:
>>>
>>>> So now, how to decide what's best? :-)
>>>>
>>>> Is a Java reader happy with the BOM? and eats it transparently? (I
>>>> think in the past that wasn't the case but I may be wrong)
>>>>
>>>> 2015-06-09 17:21 GMT+02:00 Keegan Witt <keeganw...@gmail.com>:
>>>>
>>>>> That's an excellent point, Paolo. NioGroovyMethods.newWriter claims
>>>>> (in the JavaDoc) it will write the BOM if needed, but it doesn't because
>>>>> it
>>>>> uses Java's implementation rather than with Groovy's
>>>>> writeUTF16BomIfRequired. None of the methods in NioGroovyMethods use
>>>>> writeUTF16BomIfRequired.
>>>>>
>>>>> Whichever we decide, we should be consistent.
>>>>>
>>>>> -Keegan
>>>>>
>>>>> On Tue, Jun 9, 2015 at 11:08 AM, Paolo Di Tommaso <
>>>>> paolo.ditomm...@gmail.com> wrote:
>>>>>
>>>>>> I'm wondering if NioGroovyMethods that implement the write methods
>>>>>> for Path should do the same.
>>>>>>
>>>>>>
>>>>>> Cheers,
>>>>>> Paolo
>>>>>>
>>>>>>
>>>>>> On Tue, Jun 9, 2015 at 4:02 PM, Keegan Witt <keeganw...@gmail.com>
>>>>>> wrote:
>>>>>>
>>>>>>> Cool. I'll wait for PR 36 to be merged first, because I also was
>>>>>>> thinking the Javadoc would be changed from
>>>>>>> is "UTF-16BE" or "UTF-16LE"
>>>>>>> to
>>>>>>> is "UTF-16BE" or "UTF-16LE" (or an equivalent alias)
>>>>>>>
>>>>>>> -Keegan
>>>>>>>
>>>>>>>
>>>>>>> On Tue, Jun 9, 2015 at 9:08 AM, Guillaume Laforge <
>>>>>>> glafo...@gmail.com> wrote:
>>>>>>>
>>>>>>>>
>>>>>>>> 2015-06-09 15:04 GMT+02:00 Keegan Witt <keeganw...@gmail.com>:
>>>>>>>>
>>>>>>>>> Created GROOVY-7461
>>>>>>>>> <https://issues.apache.org/jira/browse/GROOVY-7461> and PR 36
>>>>>>>>> <https://github.com/apache/incubator-groovy/pull/36>.
>>>>>>>>>
>>>>>>>>
>>>>>>>> Cool!
>>>>>>>>
>>>>>>>>
>>>>>>>>> How would you feel about a PR to copy the Javadoc comment
>>>>>>>>> mentioning the UTF-16 BOM on File.newWriter to all the other
>>>>>>>>> methods that use writeUTF16BomIfRequired (at least until we
>>>>>>>>> decide we're going to change the current behavior)?
>>>>>>>>>
>>>>>>>>
>>>>>>>> Right, worth it!
>>>>>>>>
>>>>>>>>
>>>>>>>>>
>>>>>>>>> -Keegan
>>>>>>>>>
>>>>>>>>> On Tue, Jun 9, 2015 at 8:17 AM, Guillaume Laforge <
>>>>>>>>> glafo...@gmail.com> wrote:
>>>>>>>>>
>>>>>>>>>> Good point!
>>>>>>>>>>
>>>>>>>>>> 2015-06-09 14:11 GMT+02:00 Keegan Witt <keeganw...@gmail.com>:
>>>>>>>>>>
>>>>>>>>>>> That's only available in Java 7. Isn't Groovy still targeting
>>>>>>>>>>> 1.6 for the non-indy version?
>>>>>>>>>>>
>>>>>>>>>>> -Keegan
>>>>>>>>>>> On Jun 9, 2015 7:56 AM, "Guillaume Laforge" <glafo...@gmail.com>
>>>>>>>>>>> wrote:
>>>>>>>>>>>
>>>>>>>>>>>> Well spotted!
>>>>>>>>>>>>
>>>>>>>>>>>> You could also compare with the StandardCharset, instead of
>>>>>>>>>>>> going through the name comparison:
>>>>>>>>>>>>
>>>>>>>>>>>> http://docs.oracle.com/javase/7/docs/api/java/nio/charset/StandardCharsets.html
>>>>>>>>>>>>
>>>>>>>>>>>> 2015-06-09 13:49 GMT+02:00 Keegan Witt <keeganw...@gmail.com>:
>>>>>>>>>>>>
>>>>>>>>>>>>> No, it's a Groovy bug.
>>>>>>>>>>>>>
>>>>>>>>>>>>> private static void writeUTF16BomIfRequired(final String charset,
>>>>>>>>>>>>> final OutputStream stream) throws IOException {
>>>>>>>>>>>>> if ("UTF-16BE".equals(charset)) {
>>>>>>>>>>>>> writeUtf16Bom(stream, true);
>>>>>>>>>>>>> } else if ("UTF-16LE".equals(charset)) {
>>>>>>>>>>>>> writeUtf16Bom(stream, false);
>>>>>>>>>>>>> }
>>>>>>>>>>>>> }
>>>>>>>>>>>>>
>>>>>>>>>>>>> should be
>>>>>>>>>>>>>
>>>>>>>>>>>>> private static void writeUTF16BomIfRequired(final String charset,
>>>>>>>>>>>>> final OutputStream stream) throws IOException {
>>>>>>>>>>>>> if ("UTF-16BE".equals(Charset.forName(charset).name())) {
>>>>>>>>>>>>> writeUtf16Bom(stream, true);
>>>>>>>>>>>>> } else if
>>>>>>>>>>>>> ("UTF-16LE".equals(Charset.forName(charset).name())) {
>>>>>>>>>>>>> writeUtf16Bom(stream, false);
>>>>>>>>>>>>> }
>>>>>>>>>>>>> }
>>>>>>>>>>>>>
>>>>>>>>>>>>> in org.codehaus.groovy.runtime.ResourceGroovyMethods. We'll
>>>>>>>>>>>>> probably want to fix that regardless of what we decide on the
>>>>>>>>>>>>> *withPrintWriter* question. I'll open a Jira and a PR.
>>>>>>>>>>>>>
>>>>>>>>>>>>> -Keegan
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> On Tue, Jun 9, 2015 at 3:21 AM, Guillaume Laforge <
>>>>>>>>>>>>> glafo...@gmail.com> wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>>> From Groovy's point of view (ie. when you're coding in
>>>>>>>>>>>>>> Groovy), the BOM is automatically discarded when you use one of
>>>>>>>>>>>>>> our reader
>>>>>>>>>>>>>> methods (withReader, etc), so it's transparent whether the BOM
>>>>>>>>>>>>>> is here or
>>>>>>>>>>>>>> not.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I tend to think that having the BOM always is a good thing (I
>>>>>>>>>>>>>> even thought that was mandatory), but Groovy should guess the
>>>>>>>>>>>>>> endianness
>>>>>>>>>>>>>> regardless anyway.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Happy to hear what others think too about all this though.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Guillaume
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> 2015-06-08 23:20 GMT+02:00 Keegan Witt <keeganw...@gmail.com>
>>>>>>>>>>>>>> :
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> The code as-is today writes the BOM regardless of platform.
>>>>>>>>>>>>>>> I just tested in Linux with the same results. I think there
>>>>>>>>>>>>>>> are 2 parts to
>>>>>>>>>>>>>>> the question of "what's the correct behavior?"
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> 1. Should the BOM be written at all, particularly when the
>>>>>>>>>>>>>>> platform is Windows?
>>>>>>>>>>>>>>> 2. Should the behavior of *withPrintWriter* differ (even
>>>>>>>>>>>>>>> if the difference is to be smarter) from the behavior of *new
>>>>>>>>>>>>>>> PrintWriter*?
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> *Discussion*
>>>>>>>>>>>>>>> 1. Strictly speaking, yes. Because RFC 2781
>>>>>>>>>>>>>>> <http://tools.ietf.org/html/rfc2781> states in section 4.3
>>>>>>>>>>>>>>> to assume big endian if there is no BOM. However, in practice,
>>>>>>>>>>>>>>> many
>>>>>>>>>>>>>>> applications disregard the RFC and assume little-endian because
>>>>>>>>>>>>>>> that's what Windows
>>>>>>>>>>>>>>> does
>>>>>>>>>>>>>>> <https://msdn.microsoft.com/en-us/library/windows/desktop/dd374101%28v=vs.85%29.aspx>.
>>>>>>>>>>>>>>> Because of this, the behavior could be changed so that when
>>>>>>>>>>>>>>> writing
>>>>>>>>>>>>>>> UTF-16LE on Windows, it doesn't write the BOM. But in my
>>>>>>>>>>>>>>> opinion, it's
>>>>>>>>>>>>>>> best practice to always write a BOM when working with UTF-16,
>>>>>>>>>>>>>>> and Java
>>>>>>>>>>>>>>> should have done this in their implementation of their
>>>>>>>>>>>>>>> PrintWriter.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> 2. This is a tough one. Arguably, *withPrintWriter* is
>>>>>>>>>>>>>>> doing the smarter, more correct behavior, but the typical user
>>>>>>>>>>>>>>> would assume
>>>>>>>>>>>>>>> this is just a shorthand convenience for newing up a
>>>>>>>>>>>>>>> PrintWriter (I
>>>>>>>>>>>>>>> certainly did). So the question is, is it better to just
>>>>>>>>>>>>>>> document this
>>>>>>>>>>>>>>> difference in the GroovyDoc? Or to change the behavior to be
>>>>>>>>>>>>>>> closer to
>>>>>>>>>>>>>>> Java? And if the latter, what breakages would that cause
>>>>>>>>>>>>>>> within Groovy
>>>>>>>>>>>>>>> itself? Making that change could break folks in production,
>>>>>>>>>>>>>>> because they
>>>>>>>>>>>>>>> could rely on that BOM being there, in cases for example where
>>>>>>>>>>>>>>> the file is
>>>>>>>>>>>>>>> created on Windows, but then processed on Linux or when working
>>>>>>>>>>>>>>> with a
>>>>>>>>>>>>>>> third party library that is more picky about the presence of a
>>>>>>>>>>>>>>> BOM.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> -Keegan
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> On Mon, Jun 8, 2015 at 4:32 PM, Guillaume Laforge <
>>>>>>>>>>>>>>> glafo...@gmail.com> wrote:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Now... is it what should be done or not is the good
>>>>>>>>>>>>>>>> question to ask :-)
>>>>>>>>>>>>>>>> Does Windows manages to open UTF-16 files without BOMs?
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 2015-06-08 22:17 GMT+02:00 Keegan Witt <
>>>>>>>>>>>>>>>> keeganw...@gmail.com>:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> I forgot to mention that. Yes, I ran the test mentioned
>>>>>>>>>>>>>>>>> in Windows.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> On Mon, Jun 8, 2015 at 3:54 PM, Guillaume Laforge <
>>>>>>>>>>>>>>>>> glafo...@gmail.com> wrote:
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> That's a good question.
>>>>>>>>>>>>>>>>>> I guess this is happening on Windows? (I haven't tried
>>>>>>>>>>>>>>>>>> here, since I'm on OS X)
>>>>>>>>>>>>>>>>>> I think BOMs were mandatory in text files on Windows.
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> 2015-06-08 17:53 GMT+02:00 Keegan Witt <
>>>>>>>>>>>>>>>>>> keeganw...@gmail.com>:
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> I've always taken a perverse pleasure in character
>>>>>>>>>>>>>>>>>>> encoding problems. I was intrigued by this SO question
>>>>>>>>>>>>>>>>>>> <http://stackoverflow.com/questions/30538461/why-groovy-file-write-with-utf-16le-produce-bom-char>
>>>>>>>>>>>>>>>>>>> on
>>>>>>>>>>>>>>>>>>> UTF 16 BOMs in Java vs Groovy.
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> It appears using withPrintWriter(charset) produces a
>>>>>>>>>>>>>>>>>>> BOM whereas new PrintWriter(file, charset) does not.
>>>>>>>>>>>>>>>>>>> As demonstrated here:
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> File file = new File("tmp.txt")try {
>>>>>>>>>>>>>>>>>>> String text = " "
>>>>>>>>>>>>>>>>>>> String charset = "UTF-16LE"
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> file.withPrintWriter(charset) { it << text }
>>>>>>>>>>>>>>>>>>> println "withPrintWriter"
>>>>>>>>>>>>>>>>>>> file.getBytes().each { System.out.format("%02x ", it) }
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> PrintWriter w = new PrintWriter(file, charset)
>>>>>>>>>>>>>>>>>>> w.print(text)
>>>>>>>>>>>>>>>>>>> w.close()
>>>>>>>>>>>>>>>>>>> println "\n\nnew PrintWriter"
>>>>>>>>>>>>>>>>>>> file.getBytes().each { System.out.format("%02x ", it)
>>>>>>>>>>>>>>>>>>> }} finally {
>>>>>>>>>>>>>>>>>>> file.delete()}
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> Outputs
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> withPrintWriter
>>>>>>>>>>>>>>>>>>> ff fe 20 00
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> new PrintWriter
>>>>>>>>>>>>>>>>>>> 20 00
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> Is this difference in behavior intentional? It seems
>>>>>>>>>>>>>>>>>>> kinda odd to me.
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> -Keegan
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> --
>>>>>>>>>>>>>>>>>> Guillaume Laforge
>>>>>>>>>>>>>>>>>> Groovy Project Manager
>>>>>>>>>>>>>>>>>> Product Ninja & Advocate at Restlet <http://restlet.com>
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> Blog: http://glaforge.appspot.com/
>>>>>>>>>>>>>>>>>> Social: @glaforge <http://twitter.com/glaforge> / Google+
>>>>>>>>>>>>>>>>>> <https://plus.google.com/u/0/114130972232398734985/posts>
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> --
>>>>>>>>>>>>>>>> Guillaume Laforge
>>>>>>>>>>>>>>>> Groovy Project Manager
>>>>>>>>>>>>>>>> Product Ninja & Advocate at Restlet <http://restlet.com>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Blog: http://glaforge.appspot.com/
>>>>>>>>>>>>>>>> Social: @glaforge <http://twitter.com/glaforge> / Google+
>>>>>>>>>>>>>>>> <https://plus.google.com/u/0/114130972232398734985/posts>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> --
>>>>>>>>>>>>>> Guillaume Laforge
>>>>>>>>>>>>>> Groovy Project Manager
>>>>>>>>>>>>>> Product Ninja & Advocate at Restlet <http://restlet.com>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Blog: http://glaforge.appspot.com/
>>>>>>>>>>>>>> Social: @glaforge <http://twitter.com/glaforge> / Google+
>>>>>>>>>>>>>> <https://plus.google.com/u/0/114130972232398734985/posts>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> --
>>>>>>>>>>>> Guillaume Laforge
>>>>>>>>>>>> Groovy Project Manager
>>>>>>>>>>>> Product Ninja & Advocate at Restlet <http://restlet.com>
>>>>>>>>>>>>
>>>>>>>>>>>> Blog: http://glaforge.appspot.com/
>>>>>>>>>>>> Social: @glaforge <http://twitter.com/glaforge> / Google+
>>>>>>>>>>>> <https://plus.google.com/u/0/114130972232398734985/posts>
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> --
>>>>>>>>>> Guillaume Laforge
>>>>>>>>>> Groovy Project Manager
>>>>>>>>>> Product Ninja & Advocate at Restlet <http://restlet.com>
>>>>>>>>>>
>>>>>>>>>> Blog: http://glaforge.appspot.com/
>>>>>>>>>> Social: @glaforge <http://twitter.com/glaforge> / Google+
>>>>>>>>>> <https://plus.google.com/u/0/114130972232398734985/posts>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>>>>> Guillaume Laforge
>>>>>>>> Groovy Project Manager
>>>>>>>> Product Ninja & Advocate at Restlet <http://restlet.com>
>>>>>>>>
>>>>>>>> Blog: http://glaforge.appspot.com/
>>>>>>>> Social: @glaforge <http://twitter.com/glaforge> / Google+
>>>>>>>> <https://plus.google.com/u/0/114130972232398734985/posts>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> Guillaume Laforge
>>>> Groovy Project Manager
>>>> Product Ninja & Advocate at Restlet <http://restlet.com>
>>>>
>>>> Blog: http://glaforge.appspot.com/
>>>> Social: @glaforge <http://twitter.com/glaforge> / Google+
>>>> <https://plus.google.com/u/0/114130972232398734985/posts>
>>>>
>>>
>>>
>>
>>
>> --
>> Guillaume Laforge
>> Groovy Project Manager
>> Product Ninja & Advocate at Restlet <http://restlet.com>
>>
>> Blog: http://glaforge.appspot.com/
>> Social: @glaforge <http://twitter.com/glaforge> / Google+
>> <https://plus.google.com/u/0/114130972232398734985/posts>
>>
>
>
--
Guillaume Laforge
Groovy Project Manager
Product Ninja & Advocate at Restlet <http://restlet.com>
Blog: http://glaforge.appspot.com/
Social: @glaforge <http://twitter.com/glaforge> / Google+
<https://plus.google.com/u/0/114130972232398734985/posts>
