Parsing error when encountering numeric property used for indexer

[dustinburson]

Hello!

I am one of the maintainers of the repository https://github.com/microsoft/FHIR-Converter which uses Liquid templates to convert data from one healthcare standard (Hl7v2, CCDA) to another (FHIR). The engine is currently based on DotLiquid and I am doing an investigation on potential performance improvements of switching the engine over to Fluid.

One issue I have hit is the data model the Hl7 message is loaded into uses string and numeric indexers. One example is below where MSH is the string indexer and 10 is the numeric indexer.

{{ firstSegments.MSH.10.Value }}

For the string indexers I have been able to build an adapter using the IFluidIndexable interface but since the numeric indexer is failing at the template parser, I haven't been able to find a solution.

I have a few work arounds, but they all require modifying the template content in some way which I am trying to avoid.

My questions are:

• Is accessing a numeric indexer on a class like in the example above supported but I am doing something incorrect?
• If not is there a recommend way to override the parser for this specific case?
• If the above is not possible, is this something you would consider supporting in the project and take a contribution for?

Thank you!

[sebastienros]

Quick thought before I look deeper, have you tried the indexer syntax like MSH[10] or MSH["10"] ?