Cringe

OTP-native terminal UI for Elixir.

Cringe is an experiment in building interactive terminal apps with declarative layouts, supervised runtimes, semantic input events, render-only widgets, and ExUnit-friendly render assertions. The name is a joke; the goal is serious terminal UI ergonomics for the BEAM.

Status

Early alpha. The API is not stable yet, but Cringe is usable for small interactive terminal experiments.

First document

use Cringe

box padding: 1 do
  column gap: 1 do
    text("Cringe", color: :green, bold: true)
    text("Terminal UI for the BEAM")
  end
end
|> render(width: 80, ansi: true)
|> IO.puts()

Render-only widgets

use Cringe

column gap: 1 do
  spinner(frame: 2, label: "Loading")
  progress(value: 0.42, width: 16, label: "Build")
  input(value: "cringe", focused: true, width: 24)
  select(options: ["Dashboard", "Logs", "Settings"], selected: 1)
end

Interactive app

defmodule Counter do
  use Cringe.App

  def init(_opts), do: {:ok, %{count: 0}}
  def handle_event(%Cringe.Event.Key{key: :up}, state), do: {:noreply, %{state | count: state.count + 1}}
  def render(state), do: box(text("Count: #{state.count}"), padding: 1)
end

{:ok, app} = Cringe.run(Counter, backend: Cringe.Runtime.Backend.Terminal)
Cringe.Runtime.dispatch(app, Cringe.Event.key(:up))
Cringe.Runtime.paint(app)

Run examples locally:

mix run examples/hello.exs
mix run examples/dashboard.exs
mix run examples/layout.exs
mix run examples/dsl.exs
mix run examples/widgets.exs
mix run examples/counter.exs
mix run examples/interactive_counter.exs
mix run examples/interactive_input.exs
mix run examples/form.exs

Installation

Once published, add cringe to your dependencies:

def deps do
  [
    {:cringe, "~> 0.2"}
  ]
end

Documentation is published at https://hexdocs.pm/cringe.

Benchmarks

Cringe includes local Benchee benchmarks for render, canvas, painter, and input paths:

mix bench

Benchmarks are for local regression checks and are not part of CI.

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