//! This example demonstrates using the [attribute macro](https://doc.rust-lang.org/reference/procedural-macros.html#attribute-macros) //! [`display_with`] to seamlessly augment field representations in a [`Table`] display. //! //! * [`display_with`] functions act as transformers during [`Table`] instantiation. //! //! * Note how [`display_with`] works with [std] and custom functions alike. //! //! * [`display_with`] attributes can be constructed in two ways (shown below). //! //! * Attribute arguments can be directly overridden with static values, effectively ignoring the //! augmented fields natural value entirely. Even an entire object can be passed as context with `self`. use std::borrow::Cow; use tabled::{Table, Tabled}; #[derive(Tabled)] #[tabled(rename_all = "camelCase")] struct Country { name: &'static str, capital_city: &'static str, #[tabled(display_with("display_perimeter", self))] surface_area_km2: f32, #[tabled(display_with = "str::to_lowercase")] national_currency: &'static str, national_currency_short: &'static str, } fn display_perimeter(country: &Country) -> Cow<'_, str> { if country.surface_area_km2 > 1_000_000.0 { "Very Big Land".into() } else { "Big Land".into() } } impl Country { fn new( name: &'static str, national_currency: &'static str, national_currency_short: &'static str, capital_city: &'static str, surface_area_km2: f32, ) -> Self { Self { name, national_currency, national_currency_short, capital_city, surface_area_km2, } } } fn main() { let data = [ Country::new("Afghanistan", "Afghani", "AFN", "Kabul", 652867.0), Country::new("Angola", "Kwanza", "AOA", "Luanda", 1246700.0), Country::new("Canada", "Canadian Dollar", "CAD", "Ottawa", 9984670.0), ]; let table = Table::new(data); println!("{table}"); }