Module Tjr_path_resolution.Intf

Main types; don't open - comp_ is aliased to string

type 'did state = {
cwd : 'did;
is_absolute : bool;
path : string;
}

During path resolution we maintain a state:

  • cwd, the current directory
  • is_absolute, whether we are working with an absolute path
  • path, the path itself, as a string (but without a leading slash, which is dealt with by is_absolute)
module Public : sig ... end
include Public
type comp_ = string

Path components

type ('fid, 'did, 'sid) resolved_comp =
| RC_file of 'fid
| RC_dir of 'did
| RC_sym of 'sid * string
| RC_missing

fid - file id; did - dir id; sid - symlink id

type ('fid, 'did, 'sid, 't) fs_ops = {
root : 'did;
resolve_comp : 'did -> comp_ -> (('fid, 'did, 'sid) resolved_comp, 't) Tjr_monad.m;
}

Operations we require from the underlying filesystem; essentially we need to be able to look up a component in a directory

During path resolution, we need control over whether the last component should be followed if it is a symlink

type ('fid, 'did, 'sid) simplified_result' =
| File of 'fid
| Dir of 'did
| Sym of 'sid * string
| Missing

The result of path resolution (simplified to reduce complexity). A "successful" resolution gives one of the following

type ('fid, 'did, 'sid) simplified_result = {
parent_id : 'did;
comp : comp_;
result : ('fid, 'did, 'sid) simplified_result';
trailing_slash : bool;
}

We also need additional information about the resolved result, such as the containing directory, the last path component, and whether there was a trailing slash on the path

type ('fid, 'did) resolved_err = [
| `File_followed_by_slash_etc of 'did state * comp_ * 'fid
| `Missing_slash_etc of comp_ * 'did * string
]
type ('fid, 'did, 'sid) resolved_path_or_err = (('fid, 'did, 'sid) simplified_result, ('fid, 'did) resolved_err) Stdlib.result