Standardbibliothek

Antra::FS

import Antra::FS

Filesystem operations for Antra.

FS is the path-oriented companion to Antra::IO and Antra::IO::File. Use it for existence checks, directory creation, copying, moving, removing, and simple permission changes.

Return style:

checks like exists(...), is_file(...), is_dir(...) return bool
mutating operations return %Ok[undef] or %Err[%Error{...}]
temp_file(...) / temp_dir(...) return %Ok[path] or %Err[%Error{...}]

Überblick#

Fuer pfadbasierte Dateisystem-Operationen, die nicht an offene Handles gebunden sind.

Die erste kleine API ist bewusst knapp gehalten:

FS.exists(...) -> bool
FS.is_file(...) -> bool
FS.is_dir(...) -> bool
FS.mkdir(...) -> %Ok[undef] | %Err[%Error{...}]
FS.mkdir_p(...) -> %Ok[undef] | %Err[%Error{...}]
FS.rm(...) -> %Ok[undef] | %Err[%Error{...}]
FS.rmdir(...) -> %Ok[undef] | %Err[%Error{...}]
FS.cp(...) -> %Ok[undef] | %Err[%Error{...}]
FS.mv(...) -> %Ok[undef] | %Err[%Error{...}]
FS.chmod(...) -> %Ok[undef] | %Err[%Error{...}] — Modus als Zahl, am besten oktal: FS.chmod(path, 0o755)
FS.list(dir) -> %Ok[[name, ...]] | %Err[...] — Einträge sortiert, ohne ./..
FS.copy_tree(source, target) -> %Ok[undef] | %Err[...] — Verzeichnis rekursiv kopieren
FS.remove_tree(path) -> %Ok[undef] | %Err[...] — rekursiv löschen; fehlt der Pfad, ist das kein Fehler

Bei Fehlern kannst du also im Result-Kanal direkt err.message lesen. Wenn du an einer Boundary hart scheitern willst, nimm explizit Result.unwrap!(FS.rm(path)) statt separater FS.rm!-Wrapper.

Fuer temporaere Dateien und Verzeichnisse:

FS.temp_file([prefix: = "antra", suffix: = "", dir: = undef]) -> %Ok[path] | %Err[%Error{...}]
FS.temp_dir([prefix: = "antra", dir: = undef]) -> %Ok[path] | %Err[%Error{...}]
FS.with_temp_file([prefix:, suffix:, dir:], f) -> Ergebnis von f | %Err[%Error{...}]
FS.temp_base() -> String — TMPDIR, TEMP oder TMP, sonst /tmp

temp_file legt <dir>/<prefix>-<zufall><suffix> exklusiv an (nie ueber einen schon vorhandenen Pfad hinweg) und mit Modus 0600, temp_dir mit 0700; dir: ist standardmaessig FS.temp_base(). Aufraeumen ist Sache des Aufrufers — ausser bei with_temp_file: der Callback bekommt den Pfad und muss %Ok[...] oder %Err[...] liefern; danach ist die Datei weg, auch wenn der Callback wirft (die Exception geht weiter) oder sie selbst verschoben hat.

import Antra::FS
import Antra::IO

val r = FS.with_temp_file([suffix: ".txt"]) |path| -> {
    IO.spit(path, "zwischenstand").!
    %Ok[IO.slurp(path).!]
}
println(r)                        # %Ok['zwischenstand']

Die Trennung ist absichtlich so gedacht:

Antra::IO fuer bequeme inhaltliche Datei-I/O wie slurp(...) und spit(...)
Antra::IO::File fuer offene Handles und inkrementelles Lesen/Schreiben
Antra::FS fuer Operationen auf Pfaden und Verzeichnissen

Funktionen#

chmod
copy_tree
cp
exists
is_dir
is_file
list
mkdir
mkdir_p
mv
remove_tree
rm
rmdir
temp_base
temp_dir
temp_file
with_temp_file

chmodfn</>

fn chmod(path :- String, mode :- Number) :- Result[Undef, Any]

Returns %Ok[undef] or %Err[%Error{...}].

Changes POSIX permissions using a numeric mode such as 0o755 or decimal 493.

copy_treefn</>

fn copy_tree(source, target)

Returns %Ok[undef] or %Err[%Error{...}].

Copies the directory source with everything below it to target (created if missing; existing files are overwritten).

cpfn</>

fn cp(source :- String, target :- String) :- Result[Undef, Any]

Returns %Ok[undef] or %Err[%Error{...}].

In v1, copies exactly one regular file.

existsfn</>

fn exists(path :- String) :- Bool

Returns bool.

true if the path exists, otherwise false.

is_dirfn</>

fn is_dir(path :- String) :- Bool

Returns bool.

true if the path is a directory, otherwise false.

is_filefn</>

fn is_file(path :- String) :- Bool

Returns bool.

true if the path is a regular file, otherwise false.

listfn</>

fn list(path :- String) :- Result[[String], Any]

Returns %Ok[[name, ...]] or %Err[%Error{...}].

The entries of directory path (files and directories, without . and ..), sorted by name.

mkdirfn</>

fn mkdir(path :- String) :- Result[Undef, Any]

Returns %Ok[undef] or %Err[%Error{...}].

Creates exactly one directory and fails if parent directories are missing or the path already exists.

mkdir_pfn</>

fn mkdir_p(path :- String) :- Result[Undef, Any]

Returns %Ok[undef] or %Err[%Error{...}].

Creates a directory including any missing parent directories.

mvfn</>

fn mv(source :- String, target :- String) :- Result[Undef, Any]

Returns %Ok[undef] or %Err[%Error{...}].

Moves or renames a path.

remove_treefn</>

fn remove_tree(path)

Returns %Ok[undef] or %Err[%Error{...}].

Removes the directory path with everything below it; a missing path is not an error.

rmfn</>

fn rm(path :- String) :- Result[Undef, Any]

Returns %Ok[undef] or %Err[%Error{...}].

Removes exactly one regular file.

rmdirfn</>

fn rmdir(path :- String) :- Result[Undef, Any]

Returns %Ok[undef] or %Err[%Error{...}].

Removes exactly one empty directory.

temp_basefn</>

fn temp_base() :- String

Returns String.

The platform's temp directory: TMPDIR, TEMP or TMP, otherwise /tmp.

temp_dirfn</>

fn temp_dir([prefix: = "antra", dir: = undef])

Returns %Ok[path] or %Err[%Error{...}].

Creates a new, empty directory <dir>/<prefix>-<random> with mode 0700. dir: defaults to temp_base().

temp_filefn</>

fn temp_file([prefix: = "antra", suffix: = "", dir: = undef])

Returns %Ok[path] or %Err[%Error{...}].

Creates a new, empty file <dir>/<prefix>-<random><suffix> exclusively (it never reuses an existing path) with mode 0600. dir: defaults to temp_base(). The caller removes the file; with_temp_file(...) does that automatically.

with_temp_filefn</>

fn with_temp_file(f)
fn with_temp_file([
        prefix: = "antra",
        suffix: = "",
        dir: = undef,
    ], f)

Returns the callback's %Ok[...] / %Err[...], or the %Err of temp_file(...).

Creates a temp file like temp_file(opts), calls f(path) and removes the file afterwards — also when f throws (the exception is rethrown) or has already moved or removed it.

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