Syntax Highlighting

Highlight code snippets in the terminal with beautiful syntax coloring.

Feature Flag Required

Syntax highlighting requires the syntax feature:

fast-rich = { version = "0.2.0", features = ["syntax"] }

Quick Example

use fast_rich::prelude::*;
use fast_rich::syntax::Syntax;

fn main() {
    let console = Console::new();

    let code = r#"fn main() {
    println!("Hello, World!");
}"#;

    let syntax = Syntax::new(code, "rust");
    console.print_renderable(&syntax);
}

---

Creating Syntax Objects

Basic Usage

use fast_rich::syntax::Syntax;

let json = r#"{"name": "fast-rich", "version": "0.2.0"}"#;
let syntax = Syntax::new(json, "json");

With Line Numbers

let code = r#"def hello():
    print("Hello!")

hello()"#;

let syntax = Syntax::new(code, "python")
    .line_numbers(true);

---

Supported Languages

Fast-Rich uses syntect for highlighting. Common languages include:

Language	Identifier
Rust	rust, rs
Python	python, py
JavaScript	javascript, js
TypeScript	typescript, ts
JSON	json
YAML	yaml
TOML	toml
HTML	html
CSS	css
SQL	sql
Bash	bash, sh
Go	go
C	c
C++	cpp, c++

---

Themes

Syntax supports multiple color themes:

use fast_rich::syntax::{Syntax, SyntaxTheme};

let syntax = Syntax::new(code, "rust")
    .theme(SyntaxTheme::Monokai);

Available Themes

Theme	Description
Monokai	Dark theme with vibrant colors
SolarizedDark	Solarized dark variant
SolarizedLight	Solarized light variant
Base16OceanDark	Ocean dark theme
InspiredGithub	GitHub-inspired colors

---

Display in Panel

Wrap syntax in a panel for a polished look:

let code = r#"{
    "name": "fast-rich",
    "version": "0.2.0",
    "features": ["syntax", "markdown"]
}"#;

let syntax = Syntax::new(code, "json")
    .line_numbers(true);

let panel = Panel::new(syntax)
    .title("package.json")
    .border_style(BorderStyle::Rounded);

console.print_renderable(&panel);

---

Real Terminal Output

Command:

cargo run --example syntax_highlighting --features syntax

Output:

───────────────────── Syntax Highlighting ─────────────────────

1. Rust Code
╭── main.rs ─────────────────────────────────────────────────╮
│   1 │ fn main() {                                          │
│   2 │     let message = "Hello, Fast-Rich!";               │
│   3 │     println!("{}", message);                         │
│   4 │ }                                                    │
╰────────────────────────────────────────────────────────────╯

2. JSON Data
╭── json ────────────────────────────────────────────────────╮
│   1 │ {"name": "fast_rich", "speed": "blazing"}            │
╰────────────────────────────────────────────────────────────╯

3. Python Code
╭── script.py ───────────────────────────────────────────────╮
│   1 │ def greet(name):                                     │
│   2 │     return f"Hello, {name}!"                         │
│   3 │                                                      │
│   4 │ print(greet("World"))                                │
╰────────────────────────────────────────────────────────────╯

Note

Colors in the actual terminal output vary based on the theme selected.

---

Tips

Language Detection

If you're unsure of the language, syntect often auto-detects from content:

// At minimum, provide a reasonable guess
let syntax = Syntax::new(code, "rust");

Raw Strings

Use Rust raw strings for code with special characters:

let code = r#"let x = "quoted";"#;

Performance

Syntax highlighting can be slow for very large files. Consider limiting the displayed code to relevant snippets.