Print Macros

Fast-Rich provides drop-in replacement macros for the standard library's print! and println!, automatically adding rich formatting support.

Shadowing Standard Macros

Simply import the macros to shadow the standard versions:

use fast_rich::{print, println};

fn main() {
    // Works exactly like std::println!, but with rich markup
    println!("[bold green]Success![/] Operation completed.");

    // Format arguments work as expected
    let count = 42;
    println!("Processed [cyan]{}[/] items", count);

    // Named arguments supported
    println!("{name} scored [yellow]{score}[/] points", name="Alice", score=100);
}

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Available Macros

Macro	Description
print!	Styled output to stdout (no newline)
println!	Styled output to stdout with newline
eprint!	Styled output to stderr (no newline)
eprintln!	Styled output to stderr with newline
print_raw!	Raw output to stdout (no markup parsing)
println_raw!	Raw output to stdout with newline (no parsing)
eprint_raw!	Raw output to stderr (no parsing)
eprintln_raw!	Raw output to stderr with newline (no parsing)

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Using Aliases

When you need both standard and rich printing in the same file:

use fast_rich::rprintln;  // Alias that doesn't shadow std

fn main() {
    std::println!("Standard: [bold]this is literal[/]");
    rprintln!("Rich: [bold]this is bold[/]");
}

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Raw Output for Untrusted Data

The markup parser is smart—it ignores brackets that don't match style syntax. However, if your data might accidentally form valid markup tags, use raw macros:

use fast_rich::{print, println_raw};

fn main() {
    // Most debug output works fine
    let data = vec![1, 2, 3];
    println!("[cyan]Data:[/] {:?}", data);  // Works!

    // But if data looks like a style tag...
    #[derive(Debug)]
    enum Status { Red }
    let status = vec![Status::Red];

    // ⚠️ Problem: {:?} outputs "[Red]" which is a valid color tag!
    // println!("{:?}", status);  // Would be interpreted as red styling

    // ✅ Solution: Use raw macro
    print!("[cyan]Status:[/] ");
    println_raw!("{:?}", status);  // Prints "[Red]" literally
}

Edge Case: Tag Collisions

This limitation affects data where debug output exactly matches Rich markup syntax (e.g., [Red], [bold]). Use println_raw! when printing untrusted or debug data.

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Stderr Output

For error messages and diagnostics:

use fast_rich::{eprint, eprintln, eprintln_raw};

fn main() {
    eprintln!("[bold red]Error:[/] Connection failed");

    eprint!("[yellow]Warning:[/] ");
    eprintln!("Retry in 5 seconds");

    // Raw for debug data
    eprintln_raw!("Context: {:?}", get_error_context());
}

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Try the Examples

Explore the full capabilities of print macros by running the example:

cargo run --example print_shadowing

This demo covers: - ✅ Basic styled output with format arguments - ✅ Named and positional arguments - ✅ Inline progress dots - ✅ Handling debug output with brackets - ✅ Raw output for edge cases - ✅ Stderr macros (eprint!, eprintln!) - ✅ Using aliases alongside std macros