Stdlib: Io

Alpha (v0.1). Breaking changes expected.

The Io namespace provides human-in-the-loop interaction. All four functions route through a channel (terminal by default; Slack, email, or custom via interface).

Io.ask — blocking input

Blocks the current handler until the user responds.

answer = Io.ask("How should I respond to this?")
# answer: str

choice = Io.ask("Pick a priority", options: [low, medium, high])
# choice: the enum

pick = Io.ask("Approve deployment?", options: [yes, no], via: slack)

Returns: str for free text, or the enum type when options: is provided.

Io.confirm — yes/no approval

approved = Io.confirm("Send this reply?\n\n{draft_reply}")
if approved { Email.send(draft_reply, to: email.from) }

# Via a specific channel
approved = Io.confirm("Delete 50 files?", via: slack)

Returns: bool — true if approved, false otherwise.

Io.notify — non-blocking message

Io.notify("Email classified as critical")
Io.notify("Weekly report ready", via: slack)

Does not wait for a response.

Io.show — display structured data

Io.show(email_summary)
Io.show(table(results))
Io.show(chart(metrics))

Formats structured data for the terminal or UI.

Channels

via: selects the channel. Default is terminal; the stdlib ships with slack and email channels, and additional channels can be installed by implementing the Channel interface.

Io.notify("Deploy started", via: slack)

Why a library, not keywords

Io.ask, Io.confirm, Io.notify, and Io.show are prelude functions rather than reserved words. Treating them as regular functions keeps the grammar small and lets them compose with the rest of the language: they work inside pipelines, accept lambdas for formatting, and can be wrapped by user code without fighting the parser. See The Prelude & Interfaces.