Migrate_utilsSourceAdd comments in the output. Comments are attached to a location that must appear in the output AST and cannot be a ghost location. If loc is None, use the location set with set_default_comment_loc instead.
Set the default location for comments added with add_comment.
val migrate :
packages:string list ->
units:(string -> bool) ->
modify_ast:(fname:string -> modify_ast) ->
(unit, [ `Msg of string ]) resultModify files containing occurrences to modules matched by units of packages packages using modify_ast. Will scan file in _build and in the current directory.