Terminal Formatter

ANSI escape codes for shell output.

Options

Runtime	Options
Rust	language, theme, background, width, rainbow_brackets
Elixir	language, theme, background, width, rainbow_brackets
JavaScript	language, theme, background, width, rainbowBrackets
Java	withLang(), withTheme(), withFormatter(Formatter.TERMINAL)
CLI	default formatter, --theme, --background, --width, --rainbow-brackets

Example

JavaScript

import {highlight} from '@lumis-sh/lumis'
import {terminal} from '@lumis-sh/lumis/formatters'
import javascript from '@lumis-sh/lumis/langs/javascript'
import frappe from '@lumis-sh/themes/catppuccin_frappe'

const ansi = await highlight(
  'const x = 1',
  terminal({language: javascript, theme: frappe, background: 'theme', width: 120}),
)
console.log(ansi)

Rust

use lumis::{highlight, TerminalBackground, TerminalBuilder, languages::Language, themes};

let ansi = highlight(
    "fn main() {}",
    TerminalBuilder::new()
        .language(Language::Rust)
        .theme(Some(themes::get("catppuccin_frappe").unwrap()))
        .background(TerminalBackground::Theme)
        .width(Some(120))
        .build()
        .unwrap(),
);

println!("{}", ansi);

Elixir

Lumis.highlight!(
  "fn main() {}",
  formatter: {:terminal, language: "rust", theme: "catppuccin_frappe", background: :theme, width: 120}
)

Java

import io.roastedroot.lumis4j.core.Formatter;
import io.roastedroot.lumis4j.core.Lang;
import io.roastedroot.lumis4j.core.Lumis;
import io.roastedroot.lumis4j.core.Theme;

var lumis = Lumis.builder().build();

var highlighter = lumis.highlighter()
    .withLang(Lang.JAVASCRIPT)
    .withTheme(Theme.CATPPUCCIN_FRAPPE)
    .withFormatter(Formatter.TERMINAL)
    .build();

var ansi = highlighter.highlight("const x = 1").string();
System.out.println(ansi);

lumis.close();

CLI

lumis highlight main.rs --theme catppuccin_frappe
# same as: lumis highlight main.rs --formatter terminal --theme catppuccin_frappe
lumis highlight main.rs --theme catppuccin_frappe --background theme
lumis highlight main.rs -b '#303446' -w 120

Output format

Terminal output is plain text wrapped in ANSI escape sequences:

\x1b[38;2;202;158;230mfn\x1b[0m \x1b[38;2;140;170;238mmain\x1b[0m() {}

• the source stays as terminal text, not HTML
• ANSI escape sequences set foreground color and text styles
• background / --background controls the fallback background: omit it to inherit the output background, use theme to reuse the theme background, or pass a hex color
• width / --width pads each rendered line to the requested width, which is only visible alongside background; in the CLI, auto uses the current terminal width when available, and -w is the short form
• a tab counts as four columns when measuring a line for padding, in every runtime
• \x1b[0m resets formatting between styled segments

When to use it

• CLI tools
• logs and local scripts
• previewing highlighted code in a terminal