Struct CodeSnippet

pub struct CodeSnippet { /* private fields */ }

CodeSnippet is a component of diagnostic to display code snippets.

Note: If the span spans multiple lines of code, only the first line of the code will be selected.

In the text rendered by CodeSnippet, the specific position of the span will be highlighted by an underline.

Therefore, we recommend that do not use a span with a large scope, the scope of the span should be as small as possible and point to the problem location in the code snippet.

Implementations

impl CodeSnippet

pub fn new(code_span: Span, source_map: Arc<SourceMap>) -> Self

Examples

If you want to get one line code snippet from ‘compiler_base/error/src/diagnostic/test_datas/code_snippet’ file

Line 1 Code Snippet.
Line 2 Code Snippet.

let mut sb = StyledBuffer::<DiagnosticStyle>::new();
let mut errs = vec![];

// 1. You shouled load the file and create the `SourceFile`
let filename = fs::canonicalize(&PathBuf::from("./src/diagnostic/test_datas/code_snippet"))
    .unwrap()
    .display()
    .to_string();

let src = std::fs::read_to_string(filename.clone()).unwrap();
let sm = SourceMap::new(FilePathMapping::empty());
sm.new_source_file(PathBuf::from(filename.clone()).into(), src.to_string());

// 2. You should create a code span for the code snippet.
let code_span = SpanData {
    lo: new_byte_pos(22),
    hi: new_byte_pos(42),
}.span();

// 3. You can create the `CodeSnippet` by the `SourceFile`,
// and render text "Line 2 Code Snippet.".
let code_snippet = CodeSnippet::new(code_span, Arc::new(sm));
code_snippet.format(&mut sb, &mut errs);

Trait Implementations

impl Component<DiagnosticStyle> for CodeSnippet

fn format( &self, sb: &mut StyledBuffer<DiagnosticStyle>, errs: &mut Vec<ComponentFormatError>, )

format() formats components into StyledString and saves them in StyledBuffer.