[pkg/ottl] Update Parser to understand solo conditions

[TylerHelmuth]

No description provided.

[kovrus]

It looks good! @TylerHelmuth thanks for playing around with it.

One comment that is not related to the essence of this PR: As mentioned before #14783 (comment) the transform processor can now parse both conditionStatement and transformationStatement; it should not be allowed since using conditionStatement doesn't make much sense there. Shall we pass smth that would verify what statement types are supported in the given context, for example, when creating an instance of ottl.Parser we can do the following:

... = NewParser(
         statements,
         WithFunctions(functions),
         WithSettings(settings),
         WithSupportedStatements(Statement.TRANSFORMATION), 
      )

[TylerHelmuth]

Yes we could add something like that in the future and use it during validation, but I think it could be added later in its own PR.

[kovrus]

We can probably inline this method and in tests it should be ok to use parser.ParseString("", raw)

[github-actions]

This PR was marked stale due to lack of activity. It will be closed in 14 days.

[kovrus]

Can I somehow help to move this idea forward?

[TylerHelmuth]

@kovrus I've been unable to make this work a priority as I've been working on other things. Are you able to take over?

[kovrus]

@kovrus I've been unable to make this work a priority as I've been working on other things. Are you able to take over?

@TylerHelmuth I can try! I'll take a look at it the next week.

[github-actions]

This PR was marked stale due to lack of activity. It will be closed in 14 days.

[github-actions]

Closed as inactive. Feel free to reopen if this PR is still being worked on.