highlight_source.rs

use annotate_snippets::{AnnotationKind, Group, Level, Renderer, Snippet};

fn main() {
    let source = r#"//@ compile-flags: -Z teach

#![allow(warnings)]

const CON: Vec<i32> = vec![1, 2, 3]; //~ ERROR E0010
//~| ERROR cannot call non-const method
fn main() {}
"#;
    let message = Level::ERROR
        .header("allocations are not allowed in constants")
        .id("E0010")
        .group(
            Group::new()
                .element(
                    Snippet::source(source)
                        .fold(true)
                        .origin("$DIR/E0010-teach.rs")
                        .annotation(
                            AnnotationKind::Primary
                                .span(72..85)
                                .label("allocation not allowed in constants")
                                .highlight_source(true),
                        ),
                )
                .element(
                    Level::NOTE.title("The runtime heap is not yet available at compile-time, so no runtime heap allocations can be created."),
                ),
        );

    let renderer = Renderer::styled().anonymized_line_numbers(true);
    anstream::println!("{}", renderer.render(message));
}