//! This is a library for controlling colors and formatting, such as //! red bold text or blue underlined text, on ANSI terminals. //! //! //! ## Basic usage //! //! There are three main types in this crate that you need to be //! concerned with: [`AnsiString`], [`Style`], and [`Color`]. //! //! A `Style` holds stylistic information: foreground and background colors, //! whether the text should be bold, or blinking, or other properties. The //! [`Color`] enum represents the available colors. And an [`AnsiString`] is a //! string paired with a [`Style`]. //! //! [`Color`] is also available as an alias to `Color`. //! //! To format a string, call the `paint` method on a `Style` or a `Color`, //! passing in the string you want to format as the argument. For example, //! here’s how to get some red text: //! //! ``` //! use nu_ansi_term::Color::Red; //! //! println!("This is in red: {}", Red.paint("a red string")); //! ``` //! //! It’s important to note that the `paint` method does *not* actually return a //! string with the ANSI control characters surrounding it. Instead, it returns //! an [`AnsiString`] value that has a [`Display`] implementation that, when //! formatted, returns the characters. This allows strings to be printed with a //! minimum of [`String`] allocations being performed behind the scenes. //! //! If you *do* want to get at the escape codes, then you can convert the //! [`AnsiString`] to a string as you would any other `Display` value: //! //! ``` //! use nu_ansi_term::Color::Red; //! //! let red_string = Red.paint("a red string").to_string(); //! ``` //! //! //! ## Bold, underline, background, and other styles //! //! For anything more complex than plain foreground color changes, you need to //! construct `Style` values themselves, rather than beginning with a `Color`. //! You can do this by chaining methods based on a new `Style`, created with //! [`Style::new()`]. Each method creates a new style that has that specific //! property set. For example: //! //! ``` //! use nu_ansi_term::Style; //! //! println!("How about some {} and {}?", //! Style::new().bold().paint("bold"), //! Style::new().underline().paint("underline")); //! ``` //! //! For brevity, these methods have also been implemented for `Color` values, //! so you can give your styles a foreground color without having to begin with //! an empty `Style` value: //! //! ``` //! use nu_ansi_term::Color::{Blue, Yellow}; //! //! println!("Demonstrating {} and {}!", //! Blue.bold().paint("blue bold"), //! Yellow.underline().paint("yellow underline")); //! //! println!("Yellow on blue: {}", Yellow.on(Blue).paint("wow!")); //! ``` //! //! The complete list of styles you can use are: [`bold`], [`dimmed`], [`italic`], //! [`underline`], [`blink`], [`reverse`], [`hidden`], [`strikethrough`], and [`on`] for //! background colors. //! //! In some cases, you may find it easier to change the foreground on an //! existing `Style` rather than starting from the appropriate `Color`. //! You can do this using the [`fg`] method: //! //! ``` //! use nu_ansi_term::Style; //! use nu_ansi_term::Color::{Blue, Cyan, Yellow}; //! //! println!("Yellow on blue: {}", Style::new().on(Blue).fg(Yellow).paint("yow!")); //! println!("Also yellow on blue: {}", Cyan.on(Blue).fg(Yellow).paint("zow!")); //! ``` //! //! You can turn a `Color` into a `Style` with the [`normal`] method. //! This will produce the exact same `AnsiString` as if you just used the //! `paint` method on the `Color` directly, but it’s useful in certain cases: //! for example, you may have a method that returns `Styles`, and need to //! represent both the “red bold” and “red, but not bold” styles with values of //! the same type. The `Style` struct also has a [`Default`] implementation if you //! want to have a style with *nothing* set. //! //! ``` //! use nu_ansi_term::Style; //! use nu_ansi_term::Color::Red; //! //! Red.normal().paint("yet another red string"); //! Style::default().paint("a completely regular string"); //! ``` //! //! //! ## Extended colors //! //! You can access the extended range of 256 colors by using the `Color::Fixed` //! variant, which takes an argument of the color number to use. This can be //! included wherever you would use a `Color`: //! //! ``` //! use nu_ansi_term::Color::Fixed; //! //! Fixed(134).paint("A sort of light purple"); //! Fixed(221).on(Fixed(124)).paint("Mustard in the ketchup"); //! ``` //! //! The first sixteen of these values are the same as the normal and bold //! standard color variants. There’s nothing stopping you from using these as //! `Fixed` colors instead, but there’s nothing to be gained by doing so //! either. //! //! You can also access full 24-bit color by using the `Color::Rgb` variant, //! which takes separate `u8` arguments for red, green, and blue: //! //! ``` //! use nu_ansi_term::Color::Rgb; //! //! Rgb(70, 130, 180).paint("Steel blue"); //! ``` //! //! ## Combining successive colored strings //! //! The benefit of writing ANSI escape codes to the terminal is that they //! *stack*: you do not need to end every colored string with a reset code if //! the text that follows it is of a similar style. For example, if you want to //! have some blue text followed by some blue bold text, it’s possible to send //! the ANSI code for blue, followed by the ANSI code for bold, and finishing //! with a reset code without having to have an extra one between the two //! strings. //! //! This crate can optimise the ANSI codes that get printed in situations like //! this, making life easier for your terminal renderer. The [`AnsiStrings`] //! type takes a slice of several [`AnsiString`] values, and will iterate over //! each of them, printing only the codes for the styles that need to be updated //! as part of its formatting routine. //! //! The following code snippet uses this to enclose a binary number displayed in //! red bold text inside some red, but not bold, brackets: //! //! ``` //! use nu_ansi_term::Color::Red; //! use nu_ansi_term::{AnsiString, AnsiStrings}; //! //! let some_value = format!("{:b}", 42); //! let strings: &[AnsiString<'static>] = &[ //! Red.paint("["), //! Red.bold().paint(some_value), //! Red.paint("]"), //! ]; //! //! println!("Value: {}", AnsiStrings(strings)); //! ``` //! //! There are several things to note here. Firstly, the [`paint`] method can take //! *either* an owned [`String`] or a borrowed [`&str`]. Internally, an [`AnsiString`] //! holds a copy-on-write ([`Cow`]) string value to deal with both owned and //! borrowed strings at the same time. This is used here to display a `String`, //! the result of the `format!` call, using the same mechanism as some //! statically-available `&str` slices. Secondly, that the [`AnsiStrings`] value //! works in the same way as its singular counterpart, with a [`Display`] //! implementation that only performs the formatting when required. //! //! ## Byte strings //! //! This library also supports formatting `\[u8]` byte strings; this supports //! applications working with text in an unknown encoding. [`Style`] and //! [`Color`] support painting `\[u8]` values, resulting in an [`AnsiByteString`]. //! This type does not implement [`Display`], as it may not contain UTF-8, but //! it does provide a method [`write_to`] to write the result to any value that //! implements [`Write`]: //! //! ``` //! use nu_ansi_term::Color::Green; //! //! Green.paint("user data".as_bytes()).write_to(&mut std::io::stdout()).unwrap(); //! ``` //! //! Similarly, the type [`AnsiByteStrings`] supports writing a list of //! [`AnsiByteString`] values with minimal escape sequences: //! //! ``` //! use nu_ansi_term::Color::Green; //! use nu_ansi_term::AnsiByteStrings; //! //! AnsiByteStrings(&[ //! Green.paint("user data 1\n".as_bytes()), //! Green.bold().paint("user data 2\n".as_bytes()), //! ]).write_to(&mut std::io::stdout()).unwrap(); //! ``` //! //! [`Cow`]: https://doc.rust-lang.org/std/borrow/enum.Cow.html //! [`Display`]: https://doc.rust-lang.org/std/fmt/trait.Display.html //! [`Default`]: https://doc.rust-lang.org/std/default/trait.Default.html //! [`String`]: https://doc.rust-lang.org/std/string/struct.String.html //! [`&str`]: https://doc.rust-lang.org/std/primitive.str.html //! [`Write`]: https://doc.rust-lang.org/std/io/trait.Write.html //! [`Style`]: struct.Style.html //! [`Style::new()`]: struct.Style.html#method.new //! [`Color`]: enum.Color.html //! [`Color`]: enum.Color.html //! [`AnsiString`]: type.AnsiString.html //! [`AnsiStrings`]: type.AnsiStrings.html //! [`AnsiByteString`]: type.AnsiByteString.html //! [`AnsiByteStrings`]: type.AnsiByteStrings.html //! [`write_to`]: type.AnsiByteString.html#method.write_to //! [`paint`]: type.AnsiByteString.html#method.write_to //! [`normal`]: enum.Color.html#method.normal //! //! [`bold`]: struct.Style.html#method.bold //! [`dimmed`]: struct.Style.html#method.dimmed //! [`italic`]: struct.Style.html#method.italic //! [`underline`]: struct.Style.html#method.underline //! [`blink`]: struct.Style.html#method.blink //! [`reverse`]: struct.Style.html#method.reverse //! [`hidden`]: struct.Style.html#method.hidden //! [`strikethrough`]: struct.Style.html#method.strikethrough //! [`fg`]: struct.Style.html#method.fg //! [`on`]: struct.Style.html#method.on #![crate_name = "nu_ansi_term"] #![crate_type = "rlib"] #![warn(missing_copy_implementations)] // #![warn(missing_docs)] #![warn(trivial_casts, trivial_numeric_casts)] // #![warn(unused_extern_crates, unused_qualifications)] #[cfg(target_os = "windows")] extern crate winapi; #[cfg(test)] #[macro_use] extern crate doc_comment; #[cfg(test)] doctest!("../README.md"); pub mod ansi; pub use ansi::{Infix, Prefix, Suffix}; mod style; pub use style::{Color, Style}; mod difference; mod display; pub use display::*; mod write; mod windows; pub use windows::*; mod util; pub use util::*; mod debug; pub mod gradient; pub use gradient::*; mod rgb; pub use rgb::*;