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Grammar solution request [message #1856940]

Tue, 10 January 2023 08:42

Eclipse User

Hi,

I'm requesting some help in the creation of our grammar

currently we have some base grammar with one object

Expression1 returns QueryExpression:
{Expression1 } fct=ID '(' args+=QueryExpression (',' args+=QueryExpression)* ')'
;

this should be able to retrieve functions like to_string(1) or to_integer("0");

Now on our top level we should have something to be able to retrieve
ID(args*)?.(ID (args*))*

as example we can have

field
fieldWithoutArg.id
fieldWithArg(1).id
fieldWithArg(1)..fieldWithArg(2).id

fieldWithArg(1)..fieldWithArg(2)....id
but at grammar level we encounter issues that we can't make the difference between expression1 and expression2

Reference:
ref=[ecore::EObject|ID];

Expression2 returns query::QueryExpression:
=> Reference -> ( {Expression2 .root=current} ('('args+=QueryExpression (',' args+=QueryExpression)*')')? => '.' path=[ecore::EObject|ID] )*
;

Baseexpression:
Expression1 | Expression2

Can somebody help me on this?

Re: Grammar solution request [message #1856941 is a reply to message #1856940]

Tue, 10 January 2023 08:45

Eclipse User

if they are synactially exactly the same and can be used at the same place i dont see how this should be solvable,
native question: what stops you from unifying them?

e.g. using
Reference:
ref=[ecore::EObject|ID];
everywthere.

Re: Grammar solution request [message #1856942 is a reply to message #1856941]

Tue, 10 January 2023 08:49

Eclipse User

Problem is that we don't want to touch expression1 as this is a base for every other grammar but in this case we want to extend this one with extra levels

Expression1 will only have 1 level
Expression2 can have * levels and doesn't need ot have always args, can also be without

Re: Grammar solution request [message #1856943 is a reply to message #1856942]

Tue, 10 January 2023 09:07

Eclipse User

if you have

xxxx(yyyy)

it can be both, right?

=> what about checking the restrictions using variables.
maybe you can also use IDerivedStateComputer and SyntheticLinkingSupport
to create references for the id

[Updated on: Tue, 10 January 2023 09:08] by Moderator

Re: Grammar solution request [message #1856944 is a reply to message #1856943]

Tue, 10 January 2023 09:09

Eclipse User

Hi, we would expect this is expression1 and should not be Expression2

For expression2 we should be able to have
field
fieldWithoutArg.id
fieldWithArg(1).id
fieldWithArg(1)..fieldWithArg(2).id

fieldWithArg(1)..fieldWithArg(2)....id

but we don't want to accept
fieldWithArg(1)

Re: Grammar solution request [message #1856945 is a reply to message #1856944]

Tue, 10 January 2023 09:22

Eclipse User

then maybe you should have different cases for just one element or at least 2 elements (maybe also using the => operator)

but i still would try to unify

[Updated on: Tue, 10 January 2023 09:23] by Moderator

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