Struct-valued constants are not yet implemented

As it stands today, the current thrifty schema is not able to parse struct valued constants. Wanted to know if this is a work in progress? If not, was this something consciously left out from implementation?

I am trying to load schemas for manipulating certain exceptions based on added annotations. Given that we only care about exceptions structs, is it possible to silently fail the constant schema generation so that it does not throw IllegalStateException?

Several of our thrift definitions have struct valued constants so wondering if there is any workaround?

[janarajan]

Thanks, @benjamin-bader for the pointers. The apache compiler does support it as we have plenty of struct-defined constants and use the generated code. I am taking a stab at the Loader to see if I can add a ConstValidator implementation for struct valued constants. The AntlrThrift.g4 has support for loading the struct valued constant as the grammar is in line with what Thrift grammar has.

AntlrThrift.g4

constDef : 'const' fieldType IDENTIFIER '=' constValue separator? ;

https://thrift.apache.org/docs/idl#const

Const ::= 'const' FieldType Identifier '=' ConstValue ListSeparator?

I will leave out the code gen part at this time as the immediate requirement is to be able to load the schema.

[benjamin-bader]

Nice, I’ll look forward to it! It’s been so long since I’ve worked on the schema project that I completely forgot that we absolutely did intend to do this. Turns out we never had the need so it fell off my radar.

You’re right that ConstValidator is where the work needs to happen; sounds like you’ve already figured out everything you need. Let me know how I can help, if you hit any issues!