tree 0f2eef1a7148dd14e719adf3eb67e57780e30d3c
parent 1c40f4957d1705d0ff12c86e51a61736775f7e1b
author Joe Tsai <joetsai@digital-static.net> 1541887941 -0800
committer Joe Tsai <thebrokentoaster@gmail.com> 1542063583 +0000

internal/value: expose Converter.{MessageType,EnumType}

Rather than having the Converter carry a NewMessage method, have the struct
simply expose the MessageType or EnumType since they carry more information
and are retrieved anyways as part of the functionality of NewConverter.
While changing Converter, export the fields and remove all the methods.
Also, add an IsLegacy boolean, which is useful for the later implementation
of the extension fields.

Add a wrapLegacyEnum function which is used to wrap v1 enums as v2 enums.
We use this functionality in NewLegacyConverter to detrive the EnumType.
Additionally, modify wrapLegacyMessage to return a protoreflect.ProtoMessage
to be consistent with wrapLegacyEnum which must return a protoreflect.ProtoEnum.

Change-Id: Idc8989d07e4895d30de4ebc22c9ffa7357815cad
Reviewed-on: https://go-review.googlesource.com/c/148827
Reviewed-by: Herbie Ong <herbie@google.com>