spanned_error_message

一个用于格式化带跨度错误信息的库

此库旨在在过程宏之外使用。

示例

从字符串中的文件

use spanned_error_message::{SpannedErrorMessage, Section};

// A demo file loaded from a string
let file = r#"
pub fn foo(bar: u32) -> u32 {
    return String::from(bar * 2)
}
"#;

// Section is equivalent to a Span in proc_macro.
let section = Section::from_search("String::from", file).unwrap();

// Create the message
let message = SpannedErrorMessage::new()
    .create(&section);

eprintln!("{}", message);
//    |
//  3 |     return String::from(bar * 2)
//    |            ^^^^^^^^^^^^

您还可以将proc_macro2::Span 转换为部分。您还可以从文件中加载内容。

use spanned_error_message::{SpannedErrorMessage, Section};

// Replace this with your own span
let span = proc_macro2::Span::call_site();

// Point the span to a file
let section = Section::from_span_and_path(&span, "src/lib.rs").unwrap();

// Create a message
let message = SpannedErrorMessage::new()
    .create(&section);

带有标签、标题和文件引用

use spanned_error_message::{SpannedErrorMessage, Section};

// A demo file loaded from a string
let file = r#"
pub fn foo(bar: u32) -> u32 {
    return String::from(bar * 2)
}
"#;

// Section is equivalent to a Span in proc_macro.
let mut section = Section::from_search("String::from", file).unwrap()
    .label("the problem is here");

// Set the file path. This happens automatically if you load from a file instead of a string.
section.document.path = Some("src/lib.rs".into());

let message = SpannedErrorMessage::new()
    .title("your code is broken")
    .create(&section);

eprintln!("{}", message);
// error: your code is broken
//   --> src/lib.rs:3:11
//    |
//  3 |     return String::from(bar * 2)
//    |            ^^^^^^^^^^^^ your code is broken

目前仅支持单行指针。如果您有多行跨度，它将只指向第一行。