* Merge two event methods in span API
There was an agreement to get rid of the Event interface and
consolidate the two methods for adding events into one. See #57.
* Eliminate the use of the Event interface
There is no need for the SDK to provide the implementation of the
Event interface - it is used nowhere.
* Drop the Event interface
It's dead code now.
* Make it possible to override a finish timestamp through options
Opentracing to opentelemetry bridge will certainly use this feature.
* Obey the start time option
* Add tests for events and custom start/end times
This is to make tag.Map an immutable type, so it is safe to use
concurrently. The safety is not yet fully achieved because of the
functions returning contents of the map (Value and Foreach). The
functions give callers an access to core.Value objects, which contain
a byte slice, which has pointer like semantics. So to avoid accidental
changes, we will need to copy the value if it is of BYTES type.
Fixes#59
It was printing an ID of the created span instead. Also drop the if
clause checking if span has a parent span ID - we know at this point
that the condition is always true.
* Run go generate in the precommit target
So we should always get an updated version of a file generated by a
stringer utility.
* Update the generated file
* Make CI to fail if working tree has uncommited changes
The uncommitted changes may come from the golang linter (that formats
our code among other things) and from stringer (when updated some
enumeration).