Xtext序列化器生成无效的DSL

Question

I have DSL instances and I'm trying to serialize them. I have the following grammar:

Database returns schema::Database:
    'database' name=EString  '{'
    (keys+=Key ( "," keys+=Key)*)? )
    ('structures''{' structureList+=(Group|Template)(','structureList+=(Group|Template))* '}')?
    '}'
;

Group returns schema::Group: 
    structureType=StructureType name=EString
    ('{'
        ('table' '{' tableFieldList=FieldList '}')?)
    '}')

;

First of all the serializer ignores the comma for the keys and doesn't genereta it between "keys". The second problem is "structures" This keyword is generated for every structure. When I import the files in the DSL Editor, they are not valid, so the grammar is working fine, but not the serializer. Any idea how to fix this?

Answer 1

I assume the full version of the grammar that you're having the trouble with makes use of unordered groups, doesn't it? Unordered groups are elements separated by operator "&".

If my assumption is true, then https://bugs.eclipse.org/bugs/show_bug.cgi?id=369175 would explain the behavior you're describing.