IO

Module io

import io

Bytes in, bytes out — described as attributes, not classes.

io describes streams rather than implementing them. Reader and Writer are attributes, so any type becomes a stream by carrying one — a file, a socket, or a buffer you wrote yourself. Functions that move bytes take @io.Reader or @io.Writer and never care which.

ReadStream and WriteStream are simply the ones the host hands out; os.os.stdout returns a WriteStream, and an open fs.File carries both attributes at once.

The Has… attributes are the other half: a program declares that its environment provides a writer, and a test passes one that collects into memory instead of reaching for standard output.

Contents

• Data — ReadStream, WriteStream
• Attributes — HasErrorWriter, HasStandardReader, HasStandardWriter, Reader, Writer

---

Data

ReadStream

`io/reader-writer.zirr:18`

data ReadStream {
	readFrom: fn(Int) -> Binary
}

A readable stream backed by the host, such as standard input or an open file.
Any type can be a reader by carrying @Reader; this is simply the one the host hands out.

Fields

---

WriteStream

`io/reader-writer.zirr:24`

data WriteStream {
	writeTo: fn(Binary) -> Int
}

A writable stream backed by the host, such as standard output or an open file.

Fields

---

Attributes

HasErrorWriter

`io/capabilities.zirr:11`

attr HasErrorWriter {
	writer(self) -> @Writer
}

Provides a standard error writer.
In production, this usually points to os.stderr.

Fields

---

HasStandardReader

`io/capabilities.zirr:17`

attr HasStandardReader {
	reader(self) -> @Reader
}

Provides a standard input writer.
In production, this usually points to os.stdin.

Fields

---

HasStandardWriter

`io/capabilities.zirr:5`

attr HasStandardWriter {
	writer(self) -> @Writer
}

Provides a standard out writer.
In production, this usually points to os.stdout.

Fields

---

Reader

`io/reader-writer.zirr:4`

attr Reader {
	read(self: @Reader, length: Int) -> Binary
}

Marks a type as a readable stream of bytes.

Fields

---

Writer

`io/reader-writer.zirr:10`

attr Writer {
	write(self: @Writer, buf: Binary) -> Int
}

Marks a type as a writable stream of bytes.

Fields