Boxart (Boxart v0.3.1)

Terminal graph rendering with Unicode box-drawing characters.

Accepts a Graph.t() from libgraph and renders it as a text diagram.

Quick start

graph =
  Graph.new()
  |> Graph.add_vertex("A", label: "Start")
  |> Graph.add_vertex("B", label: "Decision", shape: :diamond)
  |> Graph.add_vertex("C", label: "End")
  |> Graph.add_edge("A", "B")
  |> Graph.add_edge("B", "C", label: "yes")

IO.puts(Boxart.render(graph))

Vertex labels

Vertex labels are keyword lists (libgraph convention). Boxart recognizes:

:label — display text inside the node (defaults to inspect(vertex))
:shape — node shape atom (:rectangle, :diamond, :rounded, :hexagon, :stadium, :circle, :cylinder, etc.)
:source — raw source code string (renders as a code block with line numbers)
:start_line — first line number for code display (default: 1)
:language — language atom for syntax highlighting (e.g. :elixir)

Code nodes

When a vertex has a :source label, it renders as a code block with line numbers and optional syntax highlighting:

Graph.add_vertex(g, "block",
  source: "x = fetch(url)

case decode(x)",

  start_line: 5,
  language: :elixir
)

Edge labels

Simple string labels:

Graph.add_edge(g, "A", "B", label: "yes")

Keyword list labels for advanced edge styling:

Graph.add_edge(g, "A", "B", label: [
  label: "yes",         # display text
  style: :dotted,       # :solid (default), :dotted, :thick
  bidirectional: true,  # arrows on both ends
  arrow: false,         # no arrow (T-junction instead)
  arrow_type: :circle   # :arrow (default), :circle, :cross
])

Directions

:td / :tb — top-down (default)
:lr — left-to-right
:bt — bottom-to-top
:rl — right-to-left

Summary

Types

option()

Functions

render(graph, opts \\ [])

Renders a libgraph Graph.t() as a Unicode/ASCII text diagram.

Types

option()

@type option() ::
  {:charset, :unicode | :ascii}
  | {:direction, Boxart.Graph.direction()}
  | {:padding_x, non_neg_integer()}
  | {:padding_y, non_neg_integer()}
  | {:gap, non_neg_integer()}
  | {:theme, atom() | Boxart.Theme.t()}
  | {:rounded_edges, boolean()}
  | {:max_width, pos_integer()}
  | {:max_label_width, pos_integer()}

Functions

render(graph, opts \\ [])

@spec render(Graph.t(), [option()]) :: String.t()

Renders a libgraph Graph.t() as a Unicode/ASCII text diagram.

Options

:direction — layout direction (default: :td)
:charset — :unicode (default) or :ascii
:padding_x — horizontal padding inside node boxes (default: 4)
:padding_y — vertical padding inside node boxes (default: 2)
:gap — space between nodes (default: 4)
:theme — color theme: :default, :mono, :neon, :dracula, :nord, :amber, :phosphor, or a %Boxart.Theme{} struct
:rounded_edges — use rounded corners on edge turns (default: true)
:max_width — clamp output width to this many columns (truncates lines)
:max_label_width — maximum label width before word wrapping (default: 20)

Returns "" for empty graphs.