indenter 0.2.0

indenter

A wrapper for the fmt::Write objects that efficiently appends indentation after every newline.

This type is intended primarily for writing error reporters that gracefully format error messages that span multiple lines.

Setup

Add this to your Cargo.toml:

[dependencies]
indenter = "0.2"

Example

use std::error::Error;
use std::fmt::{self, Write};
use indenter::indented;

struct ErrorReporter<'a>(&'a dyn Error);

impl fmt::Debug for ErrorReporter<'_> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        let mut source = Some(self.0);
        let mut i = 0;

        while let Some(error) = source {
            writeln!(f)?;
            write!(indented(f).ind(i), "{}", error)?;

            source = error.source();
            i += 1;
        }

        Ok(())
    }
}

License