Hojun-Cho
5c20c40724
read → (i32 | eof | closed), write → (i32 | closed), close → (void | closed). `type eof = void` and `type closed = void` are exported as named-void variants — distinct nominal tags despite identical (zero-byte) payloads. No existing callers exercised the eof/closed sentinels (the smoke test mimics the stream pattern with its own local types), so the graduation is purely API shape — no callsite churn.
34 lines
1.0 KiB
Plaintext
34 lines
1.0 KiB
Plaintext
// io — stream interface (Plan 9 Bio / Hare io::stream shape).
|
|
//
|
|
// No closures, no methods. A `stream` is a struct of function
|
|
// pointers plus a `ctx: *void`. The error channel is the return
|
|
// value of read/write/close — Hare-shaped tagged unions instead of
|
|
// errno-style integer sentinels.
|
|
|
|
// eof — read past the end of the stream. NAMED-void so it's a
|
|
// distinct variant tag from `void` (which would be "no result yet").
|
|
export type eof = void;
|
|
|
|
// closed — operation attempted on a stream that has already been
|
|
// closed. NAMED-void; same shape, different tag.
|
|
export type closed = void;
|
|
|
|
type stream = struct {
|
|
ctx: *void,
|
|
read: fn(s: *stream, buf: []u8) (i32 | eof | closed),
|
|
write: fn(s: *stream, buf: []u8) (i32 | closed),
|
|
close: fn(s: *stream) (void | closed),
|
|
};
|
|
|
|
export fn read(s: *stream, buf: []u8) (i32 | eof | closed) = {
|
|
return s.read(s, buf);
|
|
};
|
|
|
|
export fn write(s: *stream, buf: []u8) (i32 | closed) = {
|
|
return s.write(s, buf);
|
|
};
|
|
|
|
export fn close(s: *stream) (void | closed) = {
|
|
return s.close(s);
|
|
};
|