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problem with using enums as optional elements [message #760200]

Thu, 01 December 2011 10:26

Eclipse User

Hi,

I have a problem with the use of enums and processing the grammar. I'm not using XTend, I'm using java directly.

My dsl is like this

...
ItemVisualization:
'item' id=ID
'type' dbType=DBTYPE
('caption' caption=STRING)?
('align' align=ALIGNTYPE)?
...
;

enum ALIGNTYPE :
H2 = 'h2' |
B2 = 'b2' |
K1 = 'k1'
...

While processing the DSL I can use the question ...getCaption()!=null ... to test whether the optional element caption is used or not.
In the case of align this did'nt work, getAlign() is not null and getAlign().getLiteral() deliver the first value of the enum ('h2').

How can I check wether th optional align was used or not?

Thanks

Re: problem with using enums as optional elements [message #760210 is a reply to message #760200]

Thu, 01 December 2011 10:46

Eclipse User

Hi,

at least 2 possibilities:
-you can introduce an artificial enum (default value) UNSET (first of the list
-you can bind the align keyword to a boolean feature (isAlignSet?='align' align=...)

Alex

Re: problem with using enums as optional elements [message #760235 is a reply to message #760210]

Thu, 01 December 2011 11:37

Eclipse User

Hi,

you can use a manually maintained metamodel with an unsettable eattribute
maybe you can use the metamodel postprocessor to make the eattribute unsettable too

~Christian

Re: problem with using enums as optional elements [message #760358 is a reply to message #760200]

Fri, 02 December 2011 01:33

Eclipse User

Hi,

Cool!
Thank you for your quick reply.

I tried the binding to a boolean feature and it works fine.

Joerg

Re: problem with using enums as optional elements [message #760428 is a reply to message #760358]

Fri, 02 December 2011 05:55

Eclipse User

You should be able to use the EObject#isSet method as well. Something like this should work (untested):

instance.eIsSet(instance.eClass().getEStructuralFeature("caption"))

Re: problem with using enums as optional elements [message #1016985 is a reply to message #760428]

Fri, 08 March 2013 08:34

Eclipse User

Meinte Boersma wrote on Fri, 02 December 2011 05:55

You should be able to use the EObject#isSet method as well. Something like this should work (untested):
instance.eIsSet(instance.eClass().getEStructuralFeature("caption"))

This doesn't work for the first element in the enum. eIsSet will return false, if the first enum value is specified.

I used UNSET as first element in the list and hid it from ContentAssist.

Re: problem with using enums as optional elements [message #1062412 is a reply to message #760210]

Fri, 07 June 2013 10:45

Eclipse User

I have similar problem, but my grammar dont have some keyword before enum Memory, which signal me that Memory is used.

My dsl grammar is:

...
Rule:
name=ID memory=Memory? int=INT
...
;

enum Memory:
xm = 'XM' | pm = 'PM' | ym = 'YM'
;

Thanks,
Sale

Re: problem with using enums as optional elements [message #1062504 is a reply to message #1062412]

Sat, 08 June 2013 03:00

Eclipse User

Hi the unsettable Solution does not Need keywords

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