Conan.ProcessSourceval descending_walk :
't Sigs.scheduler ->
('fd, 'error, 't) Sigs.syscall ->
'fd ->
database ->
(Metadata.t, 't) Sigs.ioval ascending_walk :
't Sigs.scheduler ->
('fd, 'error, 't) Sigs.syscall ->
'fd ->
Tree.t ->
(Metadata.t list, 't) Sigs.io