Types and functions for reading and writing files. A File value is obtained via file() and carries the path, format, and an internal reference. Capability groups — the fs/env split a sandbox profile grants via `fs#read` / `fs#update` / `env#read`, the host clock (`time#read`) and the embedding host's message channel (`host#read` / `host#append`); the functions below link in their signature.
pub struct EnvVariable {
pub name: text,
pub value: text,
}One entry of the process environment, as env_variables() answers them: the variable's name and its value, both as plain text.
pub enum Format {
TextFile,
LittleEndian,
BigEndian,
Directory,
NotExists,
}Describes how a file is opened. TextFile: read or write as UTF-8 text (default). LittleEndian: binary mode, least-significant byte first. BigEndian: binary mode, most-significant byte first. Directory: represents a directory path. NotExists: no file or directory exist.
pub enum FileResult {
Ok,
NotFound,
PermissionDenied,
IsDirectory,
NotEmpty,
Other,
}Result of a filesystem-mutating operation (delete, move, mkdir). Use ok() to get a simple boolean, or match on specific variants for detailed error handling. Every variant can actually be produced: Ok on success, NotFound for a missing / out-of-project path, PermissionDenied when the OS refuses access, IsDirectory when a file op targets a directory (e.g. deleting a directory with delete()), NotEmpty when rmdir() is given a directory that still holds entries, and Other for anything else. (--native and --interpret classify from the OS error; the wasm host reports only Ok / Other, and NotFound still comes from the loft-level existence check.)
pub fn ok(self: FileResult) -> booleanTrue when the result is FileResult.Ok. Use to test a file op for success.
pub struct File {
pub path: text,
pub size: integer,
// A fresh File reads as `NotExists` until `file()` has determined the real format for
// the path, so this default is a placeholder rather than a claim about the path — it is
// overwritten before any read.
pub format: Format = NotExists,
ref: i32?,
current: integer,
next: integer,
}A handle to a filesystem entry. Fields: path (full path), size (file size in bytes), format (open mode), current (byte position after last read), next (byte position to read next).