I/O Fundamentals

std.io contains the byte, encoding, read-state, and resource protocols shared by files, networking, HTTP, and processes. System failures throw IOException or a more specific domain exception.

Bytes

Bytes is an immutable sequence of byte values in 0..255. bytes(values:) is its public constructor; an out-of-range element throws ByteException with a stable code, element position, and value. slice(start:, length:) creates a read-only view sharing the underlying storage.

Bytes content = bytes(values: [78, 111, 114, 109])
Integer first = content.at(index: 0)
Bytes tail = content.slice(start: 1, length: 3)

toArray() returns a logically independent array. std.io.bytes defines the complete declarations.

Reading and closing

ReadChunk.Data(Bytes) means data was read, while ReadChunk.Eof means end of stream. Partial reads and writes are normal results. readAll(reader:, maximumBytes:) reads bounded content and writeAll(writer:, content:) completes a write; lack of progress, invalid progress, and exceeding limits throw StreamException.

External resources implement Resource.close(). use(resource:, body:) closes on both success and failure, preserving the body exception as primary when both body and close fail. The execution scope cleans up resources left open.

Java Binding projects returned java.io.InputStream and java.io.OutputStream as InputStream and OutputStream. Both implement the byte protocols and Resource above, and retain the same host object when passed back to a JAR API.

Text encoding

encodeText(text:, encoding:) and decodeText(content:, encoding:) provide strict UTF-8 conversion. Invalid input throws TextException.

See std.io.bytes, std.io.system, and std.io.streams for complete declarations.

See Command Line and Processes for standard input, output, and error.