GenContext

Whether a message's constructor parameters get defaults at all.

Precedence runs field, then message, then file, then the command line - most specific wins, which is how every other option here behaves.

The file-level object holding the descriptors and companion lists.

Whether lenses were asked for.

Read only so the generator can reject the request. Lenses are not implemented, and accepting the option while emitting nothing is the same failure mode as an option that never reaches the generator at all: configuration that looks applied and is not.

The Scala path of a message relative to its package, e.g. Person.Nested.

Whether the descriptors keep protoc's source-code info.

Either the command-line parameter or the file option turns it on. Reading only the file option would make --scala3_opt=retain_source_code_info silently do nothing.

The Scala package a file's types land in.

package_name wins, then java_package, then the proto package. Unless the layout is flat, the file's base name is appended, which is what keeps two files in the same proto package from colliding when both declare a Status enum.