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Posted to fop-dev@xmlgraphics.apache.org by Vincent Hennebert <vh...@gmail.com> on 2009/01/07 11:47:16 UTC
Re: svn commit: r731248 - in /xmlgraphics/fop/trunk: ./ src/documentation/content/xdocs/trunk/
src/foschema/ src/java/org/apache/fop/fonts/ src/java/org/apache/fop/fonts/autodetect/
src/java/org/apache/fop/fonts/truetype/ src/java/org/apache/fop/render/ sr...
Hi Jeremias,
> Author: jeremias
> Date: Sun Jan 4 04:59:29 2009
> New Revision: 731248
<snip/>
> + /**
> + * Sets the requested encoding mode for this font.
> + * @param mode the new encoding mode
> + */
> + public void setEncodingMode(EncodingMode mode) {
> + if (mode == null) {
> + throw new NullPointerException("mode must not be null");
> + }
> + this.encodingMode = mode;
> + }
<snip/>
> if (type1) {
> + if (encodingMode == EncodingMode.CID) {
> + throw new IllegalArgumentException(
> + "CID encoding mode not supported for Type 1 fonts");
> + }
I’d rather use assert statements instead. Anything wrong with that?
Thanks,
Vincent
Re: Assert vs Exceptions [was: svn commit: r731248 - in /xmlgraphics/fop/trunk:
./ src/documentation/content/xdocs/trunk/ src/foschema/ src/java/org/apache/fop/fonts/
src/java/org/apache/fop/fonts/autodetect/ src/java/org/apache/fop/fonts/truetype/
src/java/org/apache/fop/render/ sr...]
Posted by Vincent Hennebert <vh...@gmail.com>.
Jeremias Maerki wrote:
> On 07.01.2009 12:36:34 Vincent Hennebert wrote:
>> Jeremias Maerki wrote:
>>> Hi Vincent
>>>
>>> On 07.01.2009 11:47:16 Vincent Hennebert wrote:
>>>> Hi Jeremias,
>>>>
>>>>> Author: jeremias
>>>>> Date: Sun Jan 4 04:59:29 2009
>>>>> New Revision: 731248
>>>> <snip/>
>>>>> + /**
>>>>> + * Sets the requested encoding mode for this font.
>>>>> + * @param mode the new encoding mode
>>>>> + */
>>>>> + public void setEncodingMode(EncodingMode mode) {
>>>>> + if (mode == null) {
>>>>> + throw new NullPointerException("mode must not be null");
>>>>> + }
>>>>> + this.encodingMode = mode;
>>>>> + }
>>>> <snip/>
>>>>> if (type1) {
>>>>> + if (encodingMode == EncodingMode.CID) {
>>>>> + throw new IllegalArgumentException(
>>>>> + "CID encoding mode not supported for Type 1 fonts");
>>>>> + }
>>>> I’d rather use assert statements instead. Anything wrong with that?
>>> Nothing, it's a matter of taste. For these cases here, I prefer
>>> exceptions.
>> No big deal of course, but let me just explain my view of assert vs
>> exception:
>> - if the error is due to an illegal use of the library, I use an assert
>> and expect the developer to test his program with assertions enabled,
>> debug it and then put it in production with assertions disabled. That
>> saves some checking overhead.
>> - if the error is due to some external cause (missing resource, invalid
>> URL, etc.) then an exception is to be used.
>>
>> I don’t know the context, but in this case it seemed to correspond to
>> the first situation, hence my question.
>>
>> Vincent
>
> I understand your reasoning, but looking around on the net, I find that
> best practice seems to be to use explicit checks for parameters of
> public methods and asserts only for private methods and code consistency
> checks. That basically matches my understanding of the facility and how
> I try to use it.
>
> http://docs.sun.com/app/docs/doc/806-7930/6jgp65iks?a=view#assert-13
> http://www.jfasttrack.com/whitePapers/assertions.html
> http://goliath.ecnext.com/coms2/gi_0199-1331586/Using-assertions-in-Java-building.html
Thanks for the links. Indeed that makes sense to use exceptions in
public methods; but then they need to appear in the javadoc I think,
even if they are unchecked exceptions.
I’ll apply that convention from now on. But to be honest, I’m not too
keen on constantly checking for e.g. null arguments. I guess it’s all
a matter of how ‘obvious’ this is that the argument must not be null...
Vincent
Re: svn commit: r731248 - in /xmlgraphics/fop/trunk: ./ src/documentation/content/xdocs/trunk/ src/foschema/ src/java/org/apache/fop/fonts/ src/java/org/apache/fop/fonts/autodetect/ src/java/org/apache/fop/fonts/truetype/ src/java/org/apache/fop/render/
sr...
Posted by Jeremias Maerki <de...@jeremias-maerki.ch>.
On 07.01.2009 12:36:34 Vincent Hennebert wrote:
> Jeremias Maerki wrote:
> > Hi Vincent
> >
> > On 07.01.2009 11:47:16 Vincent Hennebert wrote:
> >> Hi Jeremias,
> >>
> >>> Author: jeremias
> >>> Date: Sun Jan 4 04:59:29 2009
> >>> New Revision: 731248
> >> <snip/>
> >>> + /**
> >>> + * Sets the requested encoding mode for this font.
> >>> + * @param mode the new encoding mode
> >>> + */
> >>> + public void setEncodingMode(EncodingMode mode) {
> >>> + if (mode == null) {
> >>> + throw new NullPointerException("mode must not be null");
> >>> + }
> >>> + this.encodingMode = mode;
> >>> + }
> >> <snip/>
> >>> if (type1) {
> >>> + if (encodingMode == EncodingMode.CID) {
> >>> + throw new IllegalArgumentException(
> >>> + "CID encoding mode not supported for Type 1 fonts");
> >>> + }
> >> I’d rather use assert statements instead. Anything wrong with that?
> >
> > Nothing, it's a matter of taste. For these cases here, I prefer
> > exceptions.
>
> No big deal of course, but let me just explain my view of assert vs
> exception:
> - if the error is due to an illegal use of the library, I use an assert
> and expect the developer to test his program with assertions enabled,
> debug it and then put it in production with assertions disabled. That
> saves some checking overhead.
> - if the error is due to some external cause (missing resource, invalid
> URL, etc.) then an exception is to be used.
>
> I don’t know the context, but in this case it seemed to correspond to
> the first situation, hence my question.
>
> Vincent
I understand your reasoning, but looking around on the net, I find that
best practice seems to be to use explicit checks for parameters of
public methods and asserts only for private methods and code consistency
checks. That basically matches my understanding of the facility and how
I try to use it.
http://docs.sun.com/app/docs/doc/806-7930/6jgp65iks?a=view#assert-13
http://www.jfasttrack.com/whitePapers/assertions.html
http://goliath.ecnext.com/coms2/gi_0199-1331586/Using-assertions-in-Java-building.html
Jeremias Maerki
Re: svn commit: r731248 - in /xmlgraphics/fop/trunk: ./ src/documentation/content/xdocs/trunk/
src/foschema/ src/java/org/apache/fop/fonts/ src/java/org/apache/fop/fonts/autodetect/
src/java/org/apache/fop/fonts/truetype/ src/java/org/apache/fop/render/ sr...
Posted by Vincent Hennebert <vh...@gmail.com>.
Jeremias Maerki wrote:
> Hi Vincent
>
> On 07.01.2009 11:47:16 Vincent Hennebert wrote:
>> Hi Jeremias,
>>
>>> Author: jeremias
>>> Date: Sun Jan 4 04:59:29 2009
>>> New Revision: 731248
>> <snip/>
>>> + /**
>>> + * Sets the requested encoding mode for this font.
>>> + * @param mode the new encoding mode
>>> + */
>>> + public void setEncodingMode(EncodingMode mode) {
>>> + if (mode == null) {
>>> + throw new NullPointerException("mode must not be null");
>>> + }
>>> + this.encodingMode = mode;
>>> + }
>> <snip/>
>>> if (type1) {
>>> + if (encodingMode == EncodingMode.CID) {
>>> + throw new IllegalArgumentException(
>>> + "CID encoding mode not supported for Type 1 fonts");
>>> + }
>> I’d rather use assert statements instead. Anything wrong with that?
>
> Nothing, it's a matter of taste. For these cases here, I prefer
> exceptions.
No big deal of course, but let me just explain my view of assert vs
exception:
- if the error is due to an illegal use of the library, I use an assert
and expect the developer to test his program with assertions enabled,
debug it and then put it in production with assertions disabled. That
saves some checking overhead.
- if the error is due to some external cause (missing resource, invalid
URL, etc.) then an exception is to be used.
I don’t know the context, but in this case it seemed to correspond to
the first situation, hence my question.
Vincent
Re: svn commit: r731248 - in /xmlgraphics/fop/trunk: ./ src/documentation/content/xdocs/trunk/ src/foschema/ src/java/org/apache/fop/fonts/ src/java/org/apache/fop/fonts/autodetect/ src/java/org/apache/fop/fonts/truetype/ src/java/org/apache/fop/render/
sr...
Posted by Jeremias Maerki <de...@jeremias-maerki.ch>.
Hi Vincent
On 07.01.2009 11:47:16 Vincent Hennebert wrote:
> Hi Jeremias,
>
> > Author: jeremias
> > Date: Sun Jan 4 04:59:29 2009
> > New Revision: 731248
> <snip/>
> > + /**
> > + * Sets the requested encoding mode for this font.
> > + * @param mode the new encoding mode
> > + */
> > + public void setEncodingMode(EncodingMode mode) {
> > + if (mode == null) {
> > + throw new NullPointerException("mode must not be null");
> > + }
> > + this.encodingMode = mode;
> > + }
> <snip/>
> > if (type1) {
> > + if (encodingMode == EncodingMode.CID) {
> > + throw new IllegalArgumentException(
> > + "CID encoding mode not supported for Type 1 fonts");
> > + }
>
> I’d rather use assert statements instead. Anything wrong with that?
Nothing, it's a matter of taste. For these cases here, I prefer
exceptions.
Jeremias Maerki