`std/fs`

The file system: File, which is both a stream's reading end and its writing end, and IoError, what every operation here fails with. The whole-file helpers (readText, writeText, readBytes, writeBytes) are for what fits in memory; chunks(), lines() and the Sink side are for everything else (docs/design/STREAMS.md).

Around the contents: remove, rename, copy, createDirectory, removeDirectory, list and walk for the tree, metadata for what a path is, symbolic links, temporary files and directories, and writeBytesAtomically for a file that is replaced whole or not at all. Every one of them takes the same path text on every system - / between the names, a drive letter on Windows - and the runtime converts it where it calls the system (docs/design/PATH.md section 6), so nothing here branches on the operating system.

Modules

std/fs/libThe file system: File, which is both a stream's reading end and its writing end, and IoError, what every operation here fails with.
std/fs/metadataWhat File.metadata answers about a path: [Metadata], with its [FileKind] and its [Permissions].

Everything

type FileA file that is open.
type FileKindWhat a path names.
type IoErrorWhat went wrong with which path.
extend IoError with From<Utf8Error>Bytes off a disk are not always UTF-8, and a String always is - so decoding is one of the ways reading fails.
type MetadataWhat a path is, how large, when it was last written, and who may do what with it.
type PermissionsThe permission bits of a file, the way POSIX writes them: read, write and execute for the owner, the group and everybody else - 0b111_101_101, which is 0o755 - plus the set-id and sticky bits above them.