Home » Modeling » TMF (Xtext) » [Xtext] Problem modifying enumeration in post processing (Xtend)
| [Xtext] Problem modifying enumeration in post processing (Xtend) [message #54144] |
Tue, 30 June 2009 09:14  |
|
Hi all,
I'm trying to migrate from oAW Xtext to TMF Xtext. Since the handling
of enumarations has been changed, I want to post process the ecore
model in order to restore the original behaviour.
In my grammar, an enumeration is defined (actually this is only one
example, I have severals. In the following case I might add a "package"
as default NULL value, but I have cases in which this doesn't work):
------------------------
enum VisibilityModifier:
public | private;
------------------------
Now I want to add the NULL literal. Only adding a new literal doesn't
help, as public becomes the default value (and its value is 0). That
is, I have to increment the value for all defined literals and then add
my NULL literal.
However, I don't get Xtend to do that. Adding a literal is working like that:
--------------------------------------------------------
Void addNullValue(ecore::EPackage p, String toEnum):
let e=(ecore::EEnum) p.getEClassifier(toEnum):
e.addLiteral("NULL", "NULL", 0);
--------------------------------------------------------
OK, but as explained, this does only solve half of the problem, I still
have to increment the values for the existing literals. I tried several
variations, the most simple one:
--------------------------------------------------------
Void addNullValue(ecore::EPackage p, String toEnum):
let e=(ecore::EEnum) p.getEClassifier(toEnum):
e.eLiterals.collect(lit|lit.setValue(lit.value+1)) ->
e.addLiteral("NULL", "NULL", 0);
--------------------------------------------------------
It does not work, the following error occurs:
--------------------------------------------------------
EvaluationException : Couldn't find property 'value' for type
mitra::VisibilityModifier
de::feu::MitraPostProcessor.ext[4181,9] on line 100 'lit.value'
de::feu::MitraPostProcessor.ext[190,37] on line 11
'addNullValue(p,"VisibilityModifier")'
--------------------------------------------------------
I do not understand how this happens. "lit" is expected to be an
intance of ecore::EEnumLiteral, that is a literal of
VisibilityModifier, and not the enum itself. (Also, there are no errors
"compiling" the Xtend source). OK, I tried it to manually iterate over
the collection (I removed the let-expression as it caused lots of weird
syntax errors I don't fully understand... I assume there is something
wrong with let, e.g., code assist does not work within a let
expression):
--------------------------------------------------------
Void addNullValue(ecore::EPackage p, String toEnum):
((ecore::EEnum)p.getEClassifier(toEnum)).eLiterals.incAllVal ues() ->
((ecore::EEnum)p.getEClassifier(toEnum)).addLiteral("NULL", "NULL", 0);
ecore::EEnumLiteral incValue(ecore::EEnumLiteral literal):
literal.setValue(literal.value+1) -> literal;
Void incAllValues(List[ecore::EEnumLiteral] list):
if list.size>0 then
list.first().incValue() ->
list.withoutFirst().incAllValues();
--------------------------------------------------------
But, again, the same error as above:
--------------------------------------------------------
EvaluationException : Couldn't find operation 'incValue()' for
mitra::VisibilityModifier.
de::feu::MitraPostProcessor.ext[4540,23] on line 111 'list.first().incValue()'
de::feu::MitraPostProcessor.ext[4016,65] on line 98
'(ecore::EEnum)p.getEClassifier(toEnum).eLiterals.incAllValu es()'
de::feu::MitraPostProcessor.ext[190,37] on line 11
'addNullValue(p,"VisibilityModifier")'
--------------------------------------------------------
At this point I assume it's a bug, as incAllValues is called without an
error, which means the list must contain EEnumLiterals -- but then how
does the enumeration sneaks into this collection again?
Do you have any solutions for my problem? (In the worst case, I'll try
to write a Java extension, but I assume this problem should be solvable
within Xtend).
Cheers
Jens
|
|
|
| Re: [Xtext] Problem modifying enumeration in post processing (Xtend) [message #54175 is a reply to message #54144] |
Tue, 30 June 2009 09:58  |
|
Hi all,
I'm answering my self, or at least add some details. I have now
implemented the extension in Java:
------------------------------------------------------------ ---
Void addNullValue(ecore::EPackage p, String toEnum):
doAddNullValue( (ecore::EEnum) p.getEClassifier(toEnum) );
Void doAddNullValue(ecore::EEnum e):
JAVA
de.feu.MitraPostProcessorHelper.addNullValue(org.eclipse.emf .ecore.EEnum);
------------------------------------------------------------ ---
with
------------------------------------------------------------ ---
public
class MitraPostProcessorHelper {
public static void addNullValue(org.eclipse.emf.ecore.EEnum e) {
for (EEnumLiteral literal : e.getELiterals()) {
literal.setValue(literal.getValue() + 1);
}
EEnumLiteral nullLiteral = EcoreFactory.eINSTANCE.createEEnumLiteral();
nullLiteral.setName("NULL");
nullLiteral.setLiteral("NULL");
nullLiteral.setValue(0);
e.getELiterals().add(0, nullLiteral);
}
}
------------------------------------------------------------ ---
Previously I assumed that it's the value of a literal which makes it
the default value (if set to 0). But that's wrong, instead it is the
first literal in the list which becomes the default one. That is,
-------------------------------------
e.getELiterals().add(0, nullLiteral);
-------------------------------------
does not make the nullLiteral the default one, but
-------------------------------------
e.getELiterals().add(0, nullLiteral);
-------------------------------------
does. As I don't know how to easily implement the last line in Xtend
(add(int, Object) is not available), I have to use Java anyway.
Cheers
Jens
|
|
| | | |
| Re: [Xtext] Problem modifying enumeration in post processing (Xtend) [message #54386 is a reply to message #54305] |
Wed, 01 July 2009 07:49 |
 Sebastian Zarnekow
Messages: 3118
Registered: July 2009 |
Senior Member |
|
|
Hi Krzysztof,
yes, that is definitely an option and should work fine.
Regards,
Sebastian
Am 01.07.2009 0:36 Uhr, schrieb Krzysztof Kowalczyk:
> Sebastian Zarnekow pisze:
>> Hi Jens,
>>
>> please be aware of the fact that JAVA extensions should not be used
>> from within the post processor step. The post processor is used from
>> inside your IDE which has no idea about any java classes that reside
>> in your project. They are only available at runtime.
>
> But it still is possible to put Java extensions to a plugin and install
> the plugin to the eclipse instance, isn't it?
> So if some extension reside in a plugin that is installed it should be
> possible to reach them.
> That, in some way, should solve the problem of QVT / ATL integration too.
>
> Regards,
> Krzysztof Kowalczyk
|
|
|
| Re: [Xtext] Problem modifying enumeration in post processing (Xtend) [message #54409 is a reply to message #54226] |
Wed, 01 July 2009 08:41 |
|
Hi Sebastian,
On 2009-06-30 15:53:23 +0200, Sebastian Zarnekow
<Sebastian.Zarnekow@itemis.de> said:
> please be aware of the fact that JAVA extensions should not be used
> from within the post processor step. The post processor is used from
> inside your IDE which has no idea about any java classes that reside in
> your project. They are only available at runtime.
I'm not sure if I understand what you mean. At least, the JAVA
extension _is_ working within the post processor step. That is, I have
an Xtext project with the Xtext grammar and the MWE workflow. I have
created a Java class within the same folder as the Xtend postprocessor
extension, and I can simply call this Java class as a JAVA extension as
decribed in my second posting. Actually, my second posting doesn't
describe a problem, it describes a running solution.
But I agree insofar as I prefer solving the problem within Xtend -- but
the problem is that Xtend obviously has a problem with the
ecore::EEnumLiteral as described in my initial posting. This is why I
created the JAVA extension in the first place.
> Can you please describe the oAW behavior, that you want to mimic?
Quite simple: I want to mimic the oAW Xtext enum behaviour with default
NULL literals.
Cheers,
Jens
|
|
|
| Re: [Xtext] Problem modifying enumeration in post processing (Xtend) [message #54434 is a reply to message #54305] |
Wed, 01 July 2009 08:47 |
|
Hi Krzysztof,
On 2009-07-01 00:36:45 +0200, Krzysztof Kowalczyk
<kowalczyk.krzysztof@gmail.com> said:
> But it still is possible to put Java extensions to a plugin and install
> the plugin to the eclipse instance, isn't it?
I haven't put the Java extension to a plugin which I installed. I
simply put the Java class in the very same folder as the post processor
extension -- and it works!
> So if some extension reside in a plugin that is installed it should be
> possible to reach them.
> That, in some way, should solve the problem of QVT / ATL integration too.
I assume that this is something different, but I'm not familiar with
how MWE/Xtend calls Java extensions. I'd assume QVT or ATL are to be
installed, and then calling an QVT / ATL transformation is simply
calling an installed Java class (i.e. the Java class executing the ATL
bytecode).
Cheers,
Jens
|
|
| |
| Re: [Xtext] Problem modifying enumeration in post processing (Xtend) [message #54488 is a reply to message #54461] |
Wed, 01 July 2009 12:21 |
|
Hi Knut,
On 2009-07-01 12:45:30 +0200, knut.wannheden@paranor.ch (Knut Wannheden) said:
>> But I agree insofar as I prefer solving the problem within Xtend -- but
>> the problem is that Xtend obviously has a problem with the
>> ecore::EEnumLiteral as described in my initial posting. This is why I
>> created the JAVA extension in the first place.
>
> You should also be able to add your enumeration literal to the end of
> the list and then set the default on the EAttributes of that type
> (using EAttribute#setDefaultValueLiteral(String)). That is then a pure
> Xtend solution.
OK.... but how? Do you have any hints?
Cheers
Jens
|
|
| |
Goto Forum:
Current Time: Thu Jul 04 09:28:13 GMT 2024
Powered by FUDForum. Page generated in 0.03643 seconds |
] 
Search
Help
Register
Login
Home
