veryl 0.20.1

A modern hardware description language
use console::{Style, style};
use similar::{ChangeTag, TextDiff};
use std::fmt;
use std::path::Path;

struct Line(Option<usize>);

impl fmt::Display for Line {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self.0 {
            None => write!(f, "    "),

            Some(idx) => write!(f, "{:<4}", idx + 1),
        }
    }
}

pub fn print_diff(file: &Path, org: &str, new: &str) {
    let diff = TextDiff::from_lines(org, new);

    println!("Diff in {}", file.to_string_lossy());

    for (idx, group) in diff.grouped_ops(3).iter().enumerate() {
        if idx > 0 {
            println!("{:-^1$}", "-", 80);
        }
        for op in group {
            for change in diff.iter_inline_changes(op) {
                let (sign, s) = match change.tag() {
                    ChangeTag::Delete => ("-", Style::new().red()),
                    ChangeTag::Insert => ("+", Style::new().green()),
                    ChangeTag::Equal => (" ", Style::new().dim()),
                };
                print!(
                    "{}{} |{}",
                    style(Line(change.old_index())).dim(),
                    style(Line(change.new_index())).dim(),
                    s.apply_to(sign).bold(),
                );
                for (emphasized, value) in change.iter_strings_lossy() {
                    if emphasized {
                        print!("{}", s.apply_to(value).underlined().on_black());
                    } else {
                        print!("{}", s.apply_to(value));
                    }
                }
                if change.missing_newline() {
                    println!();
                }
            }
        }
    }
}