Crate termdiff 

This library is for helping you create diff for displaying on the terminal

Examples

use termdiff::{diff, ArrowsTheme};
let old = "The quick brown fox and\njumps over the sleepy dog";
let new = "The quick red fox and\njumps over the lazy dog";
let mut buffer: Vec<u8> = Vec::new();
let theme = ArrowsTheme::default();
diff(&mut buffer, old, new, &theme).unwrap();
let actual: String = String::from_utf8(buffer).expect("Not valid UTF-8");

assert_eq!(
    actual,
    "< left / > right
<The quick brown fox and
<jumps over the sleepy dog
>The quick red fox and
>jumps over the lazy dog
"
);

Alternatively if you are dropping this into a format! or similar, you might want to use the displayable instead

use termdiff::{DrawDiff, SignsTheme};
let old = "The quick brown fox and\njumps over the sleepy dog";
let new = "The quick red fox and\njumps over the lazy dog";
let theme = SignsTheme::default();
let actual = format!("{}", DrawDiff::new(old, new, &theme));

assert_eq!(
    actual,
    "--- remove | insert +++
-The quick brown fox and
-jumps over the sleepy dog
+The quick red fox and
+jumps over the lazy dog
"
);

Features

This crate provides several features that can be enabled or disabled in your Cargo.toml:

Diff Algorithms

• myers - Provides a Myers diff algorithm variant. This is a from-scratch implementation of Eugene Myers’ O(ND) difference algorithm (1986) that does not depend on the similar crate. It can be used on its own (without the similar feature) and produces output compatible with the similar feature.

• similar - Uses the “similar” crate to compute diffs. This is the primary algorithm implementation.

Themes

• arrows - A simple, colorless theme that uses arrow symbols (< and >) to indicate deleted and inserted lines. The header shows “< left / > right”.

• arrows_color - A colored version of the arrows theme. Uses red for deleted content and green for inserted content. Requires the “crossterm” crate for terminal color support.

• signs - A simple, colorless theme that uses plus and minus signs (- and +) to indicate deleted and inserted lines. The header shows “— remove | insert +++”. This style is similar to traditional diff output.

• signs_color - A colored version of the signs theme. Uses red for deleted content and green for inserted content. Requires the “crossterm” crate for terminal color support.

By default, all features are enabled. You can selectively disable features by specifying default-features = false and then listing the features you want to enable.

You can define your own theme if you like

use std::borrow::Cow;

use crossterm::style::Stylize;
use termdiff::{DrawDiff, Theme};

#[derive(Debug)]
struct MyTheme {}
impl Theme for MyTheme {
    fn highlight_insert<'this>(&self, input: &'this str) -> Cow<'this, str> {
        input.into()
    }

    fn highlight_delete<'this>(&self, input: &'this str) -> Cow<'this, str> {
        input.into()
    }

    fn equal_content<'this>(&self, input: &'this str) -> Cow<'this, str> {
        input.into()
    }

    fn delete_content<'this>(&self, input: &'this str) -> Cow<'this, str> {
        input.into()
    }

    fn equal_prefix<'this>(&self) -> Cow<'this, str> {
        "=".into()
    }

    fn delete_prefix<'this>(&self) -> Cow<'this, str> {
        "!".into()
    }

    fn insert_line<'this>(&self, input: &'this str) -> Cow<'this, str> {
        input.into()
    }

    fn insert_prefix<'this>(&self) -> Cow<'this, str> {
        "|".into()
    }

    fn line_end<'this>(&self) -> Cow<'this, str> {
        "\n".into()
    }

    fn header<'this>(&self) -> Cow<'this, str> {
        format!("{}\n", "Header").into()
    }
}
let my_theme = MyTheme {};
let old = "The quick brown fox and\njumps over the sleepy dog";
let new = "The quick red fox and\njumps over the lazy dog";
let actual = format!("{}", DrawDiff::new(old, new, &my_theme));

assert_eq!(
    actual,
    "Header
!The quick brown fox and
!jumps over the sleepy dog
|The quick red fox and
|jumps over the lazy dog
"
);

Structs

ArrowsColorTheme

A simple colorful theme using arrows

ArrowsTheme

A simple colorless using arrows theme

DrawDiff

The struct that draws the diff

SignsColorTheme

A simple colorful theme using signs

SignsTheme

A simple colorless using signs theme

Enums

Algorithm

The algorithm to use for computing diffs

Traits

Theme

A Theme for customizing the appearance of diffs

Functions

diff

Print a diff to a writer

diff_with_algorithm

Print a diff to a writer using a specific algorithm