add typesafe `std/paths`, `std/files`, `std/dirs`, `std/symlinks` (#20582)

* split std/os; add typesafe std/paths
* add more files, dirs, paths
* add documentation
* add testcase
* remove tryRemoveFile
* clean up
* Delete test.nim
* apply changes
* add `add` and fixes

1 files changed, 177 insertions, 0 deletions

diff --git a/lib/std/dirs.nim b/lib/std/dirs.nim
new file mode 100644
index 000000000..e89bfc668
--- /dev/null
+++ b/lib/std/dirs.nim
@@ -0,0 +1,177 @@
+from paths import Path, ReadDirEffect, WriteDirEffect
+
+from std/private/osdirs import dirExists, createDir, existsOrCreateDir, removeDir,
+                               moveDir, walkPattern, walkFiles, walkDirs, walkDir,
+                               walkDirRec, PathComponent
+
+export PathComponent
+
+proc dirExists*(dir: Path): bool {.inline, tags: [ReadDirEffect].} =
+  ## Returns true if the directory `dir` exists. If `dir` is a file, false
+  ## is returned. Follows symlinks.
+  result = dirExists(dir.string)
+
+proc createDir*(dir: Path) {.inline, tags: [WriteDirEffect, ReadDirEffect].} =
+  ## Creates the `directory`:idx: `dir`.
+  ##
+  ## The directory may contain several subdirectories that do not exist yet.
+  ## The full path is created. If this fails, `OSError` is raised.
+  ##
+  ## It does **not** fail if the directory already exists because for
+  ## most usages this does not indicate an error.
+  ##
+  ## See also:
+  ## * `removeDir proc`_
+  ## * `existsOrCreateDir proc`_
+  ## * `copyDir proc`_
+  ## * `copyDirWithPermissions proc`_
+  ## * `moveDir proc`_
+  createDir(dir.string)
+
+proc existsOrCreateDir*(dir: Path): bool {.inline, tags: [WriteDirEffect, ReadDirEffect].} =
+  ## Checks if a `directory`:idx: `dir` exists, and creates it otherwise.
+  ##
+  ## Does not create parent directories (raises `OSError` if parent directories do not exist).
+  ## Returns `true` if the directory already exists, and `false` otherwise.
+  ##
+  ## See also:
+  ## * `removeDir proc`_
+  ## * `createDir proc`_
+  ## * `copyDir proc`_
+  ## * `copyDirWithPermissions proc`_
+  ## * `moveDir proc`_
+  result = existsOrCreateDir(dir.string)
+
+proc removeDir*(dir: Path, checkDir = false
+                ) {.inline, tags: [WriteDirEffect, ReadDirEffect].} =
+  ## Removes the directory `dir` including all subdirectories and files
+  ## in `dir` (recursively).
+  ##
+  ## If this fails, `OSError` is raised. This does not fail if the directory never
+  ## existed in the first place, unless `checkDir` = true.
+  ##
+  ## See also:
+  ## * `removeFile proc`_
+  ## * `existsOrCreateDir proc`_
+  ## * `createDir proc`_
+  ## * `copyDir proc`_
+  ## * `copyDirWithPermissions proc`_
+  ## * `moveDir proc`_
+  removeDir(dir.string, checkDir)
+
+proc moveDir*(source, dest: Path) {.inline, tags: [ReadIOEffect, WriteIOEffect].} =
+  ## Moves a directory from `source` to `dest`.
+  ##
+  ## Symlinks are not followed: if `source` contains symlinks, they themself are
+  ## moved, not their target.
+  ##
+  ## If this fails, `OSError` is raised.
+  ##
+  ## See also:
+  ## * `moveFile proc`_
+  ## * `copyDir proc`_
+  ## * `copyDirWithPermissions proc`_
+  ## * `removeDir proc`_
+  ## * `existsOrCreateDir proc`_
+  ## * `createDir proc`_
+  moveDir(source.string, dest.string)
+
+iterator walkPattern*(pattern: Path): Path {.tags: [ReadDirEffect].} =
+  ## Iterate over all the files and directories that match the `pattern`.
+  ##
+  ## On POSIX this uses the `glob`:idx: call.
+  ## `pattern` is OS dependent, but at least the `"*.ext"`
+  ## notation is supported.
+  ##
+  ## See also:
+  ## * `walkFiles iterator`_
+  ## * `walkDirs iterator`_
+  ## * `walkDir iterator`_
+  ## * `walkDirRec iterator`_
+  for p in walkPattern(pattern.string):
+    yield Path(p)
+
+iterator walkFiles*(pattern: Path): Path {.tags: [ReadDirEffect].} =
+  ## Iterate over all the files that match the `pattern`.
+  ##
+  ## On POSIX this uses the `glob`:idx: call.
+  ## `pattern` is OS dependent, but at least the `"*.ext"`
+  ## notation is supported.
+  ##
+  ## See also:
+  ## * `walkPattern iterator`_
+  ## * `walkDirs iterator`_
+  ## * `walkDir iterator`_
+  ## * `walkDirRec iterator`_
+  for p in walkFiles(pattern.string):
+    yield Path(p)
+
+iterator walkDirs*(pattern: Path): Path {.tags: [ReadDirEffect].} =
+  ## Iterate over all the directories that match the `pattern`.
+  ##
+  ## On POSIX this uses the `glob`:idx: call.
+  ## `pattern` is OS dependent, but at least the `"*.ext"`
+  ## notation is supported.
+  ##
+  ## See also:
+  ## * `walkPattern iterator`_
+  ## * `walkFiles iterator`_
+  ## * `walkDir iterator`_
+  ## * `walkDirRec iterator`_
+  for p in walkDirs(pattern.string):
+    yield Path(p)
+
+iterator walkDir*(dir: Path; relative = false, checkDir = false):
+    tuple[kind: PathComponent, path: Path] {.tags: [ReadDirEffect].} =
+  ## Walks over the directory `dir` and yields for each directory or file in
+  ## `dir`. The component type and full path for each item are returned.
+  ##
+  ## Walking is not recursive. If ``relative`` is true (default: false)
+  ## the resulting path is shortened to be relative to ``dir``.
+  ##
+  ## If `checkDir` is true, `OSError` is raised when `dir`
+  ## doesn't exist.
+  for (k, p) in walkDir(dir.string, relative, checkDir):
+    yield (k, Path(p))
+
+iterator walkDirRec*(dir: Path,
+                     yieldFilter = {pcFile}, followFilter = {pcDir},
+                     relative = false, checkDir = false): Path {.tags: [ReadDirEffect].} =
+  ## Recursively walks over the directory `dir` and yields for each file
+  ## or directory in `dir`.
+  ##
+  ## If ``relative`` is true (default: false) the resulting path is
+  ## shortened to be relative to ``dir``, otherwise the full path is returned.
+  ##
+  ## If `checkDir` is true, `OSError` is raised when `dir`
+  ## doesn't exist.
+  ##
+  ## .. warning:: Modifying the directory structure while the iterator
+  ##   is traversing may result in undefined behavior!
+  ##
+  ## Walking is recursive. `followFilter` controls the behaviour of the iterator:
+  ##
+  ## =====================   =============================================
+  ## yieldFilter             meaning
+  ## =====================   =============================================
+  ## ``pcFile``              yield real files (default)
+  ## ``pcLinkToFile``        yield symbolic links to files
+  ## ``pcDir``               yield real directories
+  ## ``pcLinkToDir``         yield symbolic links to directories
+  ## =====================   =============================================
+  ##
+  ## =====================   =============================================
+  ## followFilter            meaning
+  ## =====================   =============================================
+  ## ``pcDir``               follow real directories (default)
+  ## ``pcLinkToDir``         follow symbolic links to directories
+  ## =====================   =============================================
+  ##
+  ##
+  ## See also:
+  ## * `walkPattern iterator`_
+  ## * `walkFiles iterator`_
+  ## * `walkDirs iterator`_
+  ## * `walkDir iterator`_
+  for p in walkDirRec(dir.string, yieldFilter, followFilter, relative, checkDir):
+    yield Path(p)