Package xopotel provides gateways/connections between xop and OpenTelemetry.
SpanToLog() allows xop to be used as a logger to add "Events" to an
existing OTEL span.
SeedModifier allows using an OTEL Tracer as an xopbase.Logger
BaseLogger() creates a xopbase.Logger that can be used as a
to gateway xop logs and spans into OTEL.
OTEL supports far fewer data types than xop. Mostly, xop types can be converted cleanly, but links are a special case: links can only be added to OTEL spans when the span is created. Since xop allows links to be made at any time, links will be added as ephemeral sub-spans. Distinct, Multiple, and Locked attributes will be ignored for links.
OTEL does not support unsigned ints. uint64 will be converted to a
string and smaller unsigned ints will convert to int64.
OTEL provides no way to record links (trace_id/span_id) except as part of the initial set of "Links" associated with a span. Those links are values only (no key, no name). Xop supports arbitrary numbers of links on a per-logline basis. There is no way to record those as links using the OTEL structures so if there is more than one of them, then they'll be recorded as strings. Most of the time, a log line won't have more than one trace reference.
For both events with links, and links as span metadata, an extra OTEL span will be created just to hold the link. The extra span will be marked with span.is-link-attribute:true for span metadata and span.is-link-event for events.