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Splitting grammar in multiple files, not projects [message #1870947]

Wed, 11 September 2024 15:01

Eclipse User

Say we have a rather large grammar and we'd like to split it up in multiple files, as is common to software developers. How would we go about that without creating multiple projects?

Re: Splitting grammar in multiple files, not projects [message #1870950 is a reply to message #1870947]

Wed, 11 September 2024 15:08

Eclipse User

Hi you can simply have multiple language sections in the workflow

https://github.com/cdietrich/xtext-multi-dsl/blob/133bad08f7a5da0e8ba2bdbc06e425aeb58809f6/org.xtext.example.mydsl/src/org/xtext/example/mydsl/GenerateMyDsl.mwe2#L42

Re: Splitting grammar in multiple files, not projects [message #1870953 is a reply to message #1870950]

Wed, 11 September 2024 15:22

Eclipse User

Alright, so in essence we define grammar B to extend grammar A and then import grammar A

grammar B with A
import A as a

Furthermore, in the workflow we define all the grammars and references per grammar:

referencedResource="platform:/resource/<...>/A.xtext"

Are there any limitations to this setup? I believe I've encountered a 'Sealed' exception when trying to extend a production rule.

[Updated on: Wed, 11 September 2024 15:23] by Moderator

Re: Splitting grammar in multiple files, not projects [message #1870959 is a reply to message #1870953]

Wed, 11 September 2024 16:35

Eclipse User

Depends on what you exactly do. You cannot introduce new eattributes or ereferences without creating a new subeclass which seems to be your problem

What are you exactly doing

[Updated on: Wed, 11 September 2024 16:35] by Moderator

Re: Splitting grammar in multiple files, not projects [message #1870968 is a reply to message #1870959]

Thu, 12 September 2024 04:15

Eclipse User

Say in grammar A we have a production rule:

RuleX: 'Hello' name=ID '!';

In grammar B we have a rule which refers this rule:

grammar B with A
import A
RuleY: RuleX | 'Goodbye';

This gives the error: "Cannot add supertype 'RuleY' to sealed type 'RuleX', but can be resolved by assigning RuleX to a feature:

grammar B with A
import A
RuleY: x=RuleX | y='Goodbye';

However, I'd prefer to extend RuleX instead of encapsulating it in a feature.
I made this construct with actions to resolve:

RuleY: {RuleX} f=RuleX | {RuleZ} f='Goodbye';

but perhaps there are better ways...

[Updated on: Thu, 12 September 2024 06:16] by Moderator

Re: Splitting grammar in multiple files, not projects [message #1871007 is a reply to message #1870968]

Thu, 12 September 2024 13:18

Eclipse User

You can do a

RuleY returns RuleX: RuleX | {RuleY}'Goodbye';

Or you need to introduce Ruley as supertype for x
Already in base.
Eg by uncallled rule

Ruley: rulex

Re: Splitting grammar in multiple files, not projects [message #1871010 is a reply to message #1871007]

Thu, 12 September 2024 13:19

Eclipse User

(Depends on which hierarchy you want to achieve

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