Ocaml_protoc_compiler_lib.Pb_codegen_pluginSourcePlugin architecture.
OCaml-protoc generates code based on a number of plugins, each of which can contribute code to the output files (.ml and .mli).
type codegen_f =
?and_:unit ->
Pb_codegen_ocaml_type.type_ ->
Pb_codegen_formatting.scope ->
boolA code generation function