ydb/yql/essentials/tests/s-expressions/suites/ImplictCasts/ImplicitEqualsOverVariantStruct.yqls

(
(let config (DataSource 'config))

(let res_sink (DataSink 'result))

# Variant<Struct<Int16, Int16>>> -> Variant<Struct<Uint32, Uint64>> (false)
(let variantType (VariantType (StructType '('"a" (DataType 'Int16)) '('"b" (DataType 'Int16)))))
(let value (Variant (Int16 '"-1") '"a" variantType))
(let commonType (VariantType (StructType '('"a" (DataType 'Uint32)) '('"b" (DataType 'Uint64)))))
(let imlicitEqualsResult (Exists (StrictCast value commonType)))
(let world (Write! world res_sink (Key) imlicitEqualsResult '('('type))))

# Variant<Struct<Uint16, Uint16>>> -> Variant<Struct<Uint32, Uint64>> (true)
(let variantType (VariantType (StructType '('"a" (DataType 'Uint16)) '('"b" (DataType 'Uint16)))))
(let value (Variant (Uint16 '0) '"a" variantType))
(let commonType (VariantType (StructType '('"a" (DataType 'Uint32)) '('"b" (DataType 'Uint64)))))
(let imlicitEqualsResult (Exists (StrictCast value commonType)))
(let world (Write! world res_sink (Key) imlicitEqualsResult '('('type))))

(let world (Commit! world res_sink))
(return world)

)