I created DAFFODIL-2887, I probably forgot to respond on the users@ list about it.
On 2024-04-17 05:24 PM, Larry Barber wrote:
I don’t believe so *From:*Mike Beckerle <mbecke...@apache.org> *Sent:* Wednesday, April 17, 2024 5:22 PM *To:* users@daffodil.apache.org *Subject:* Re: No element corresponding to step {}Type found Was a bug report created for the original error?On Wed, Apr 17, 2024 at 5:13 PM Larry Barber <larry.bar...@nteligen.com <mailto:larry.bar...@nteligen.com>> wrote:Yes, Steve helped me with your best workaround, but the <sequence> change worked as well. *From:*Mike Beckerle <mbecke...@apache.org <mailto:mbecke...@apache.org>> *Sent:* Wednesday, April 17, 2024 5:08 PM *To:* users@daffodil.apache.org <mailto:users@daffodil.apache.org> *Subject:* Re: No element corresponding to step {}Type found Did you get a response about this? This may indicate a bug in Daffodil. To my eye your schema looks correct. I think ../../Type should be the right path for those discriminators. The best workaround is change to a choice by dispatch so you won't use discriminators at all. The second workaround is to put the discriminators on a sequence that appears before the elements in each choice branch. There's a small trick to this: Not this in each branch: <sequence> annotation with discriminator element of the branch </sequence> rather you must do: <sequence> <sequence> <!-- inner sequence to hold discriminator --> annotation with discriminator </sequence> element of the branch </sequence> This inner sequence is needed because otherwise the discriminator will evaluate at the END of the sequence i.e., after the element. (Section 9.5 of the DFDL spec says that discriminators on a sequence evaluate at the END of the sequence. DFDL implementations can hoist this to earlier when the behavior would not be changed, but Daffodil does not do that optimization. Personally I think this was a mistake in DFDL as it violates top-down left-to-right default behavior. But it is easily worked around by the inner sequence trick.) On Thu, Apr 4, 2024 at 9:11 AM Larry Barber <larry.bar...@nteligen.com <mailto:larry.bar...@nteligen.com>> wrote: I’m having a problem with the attached schema. In the discriminators (lines 44 & 51), I cannot get Daffodil to access the value of *Type* (line 34). When I tried *../Type*, it says valid options are *P_INT32* & *P_UINT32*, I figured I needed to go back another level, but *../../Type* doesn’t work either. At this point it says valid options are *Msg_ID* & *Parameter*, which are too far back! However, line 37 has no problem accessing *Length* (line35). Anyone have an explanation for this? …or even better, a solution?
