Struct Diag 

pub struct Diag {
    pub messages: Vec<(DiagMsg, Style)>,
    pub span: MultiSpan,
    pub children: Vec<SubDiagnostic>,
    pub code: Option<DiagId>,
    pub suggestions: Suggestions,
    pub created_at: &'static Location<'static>,
    /* private fields */
}

A compiler diagnostic.

Fields

messages: Vec<(DiagMsg, Style)>

span: MultiSpan

children: Vec<SubDiagnostic>

code: Option<DiagId>

suggestions: Suggestions

created_at: &'static Location<'static>

Implementations

impl Diag

pub fn new<M>(level: Level, msg: M) -> Diag

where M: Into<DiagMsg>,

Creates a new Diag with a single message.

pub fn new_with_messages(level: Level, messages: Vec<(DiagMsg, Style)>) -> Diag

Creates a new Diag with multiple messages.

pub fn is_error(&self) -> bool

Returns true if this diagnostic is an error.

pub fn is_note(&self) -> bool

Returns true if this diagnostic is a note.

pub fn label(&self) -> Cow<'_, str>

Formats the diagnostic messages into a single string.

pub fn label_with_style(&self, supports_color: bool) -> Cow<'_, str>

Formats the diagnostic messages into a single string with ANSI color codes if applicable.

pub fn messages(&self) -> &[(DiagMsg, Style)]

Returns the messages of this diagnostic.

pub fn level(&self) -> Level

Returns the level of this diagnostic.

pub fn id(&self) -> Option<String>

Returns the code of this diagnostic as a string.

impl Diag

Setters.

pub fn span(&mut self, span: impl Into<MultiSpan>) -> &mut Diag

Sets the span of this diagnostic.

pub fn code(&mut self, code: impl Into<DiagId>) -> &mut Diag

Sets the code of this diagnostic.

pub fn span_label(&mut self, span: Span, label: impl Into<DiagMsg>) -> &mut Diag

Adds a span/label to be included in the resulting snippet.

This is pushed onto the MultiSpan that was created when the diagnostic was first built. That means it will be shown together with the original span/label, not a span added by one of the span_{note,warn,help,suggestions} methods.

This span is not considered a “primary span”; only the Span supplied when creating the diagnostic is primary.

pub fn span_labels( &mut self, spans: impl IntoIterator<Item = Span>, label: impl Into<DiagMsg>, ) -> &mut Diag

Labels all the given spans with the provided label. See Self::span_label() for more information.

impl Diag

Sub-diagnostics.

pub fn warn(&mut self, msg: impl Into<DiagMsg>) -> &mut Diag

Add a warning attached to this diagnostic.

pub fn span_warn( &mut self, span: impl Into<MultiSpan>, msg: impl Into<DiagMsg>, ) -> &mut Diag

Prints the span with a warning above it. This is like Diag::warn(), but it gets its own span.

pub fn note(&mut self, msg: impl Into<DiagMsg>) -> &mut Diag

Add a note to this diagnostic.

pub fn span_note( &mut self, span: impl Into<MultiSpan>, msg: impl Into<DiagMsg>, ) -> &mut Diag

Prints the span with a note above it. This is like Diag::note(), but it gets its own span.

pub fn highlighted_note( &mut self, messages: Vec<(impl Into<DiagMsg>, Style)>, ) -> &mut Diag

pub fn note_once(&mut self, msg: impl Into<DiagMsg>) -> &mut Diag

Prints the span with a note above it. This is like Diag::note(), but it gets emitted only once.

pub fn span_note_once( &mut self, span: impl Into<MultiSpan>, msg: impl Into<DiagMsg>, ) -> &mut Diag

Prints the span with a note above it. This is like Diag::note_once(), but it gets its own span.

pub fn help(&mut self, msg: impl Into<DiagMsg>) -> &mut Diag

Add a help message attached to this diagnostic.

pub fn help_once(&mut self, msg: impl Into<DiagMsg>) -> &mut Diag

Prints the span with a help above it. This is like Diag::help(), but it gets its own span.

pub fn highlighted_help( &mut self, msgs: Vec<(impl Into<DiagMsg>, Style)>, ) -> &mut Diag

Add a help message attached to this diagnostic with a customizable highlighted message.

pub fn span_help( &mut self, span: impl Into<MultiSpan>, msg: impl Into<DiagMsg>, ) -> &mut Diag

Prints the span with some help above it. This is like Diag::help(), but it gets its own span.

impl Diag

Suggestions.

pub fn disable_suggestions(&mut self) -> &mut Diag

Disallow attaching suggestions to this diagnostic. Any suggestions attached e.g. with the span_suggestion_* methods (before and after the call to disable_suggestions) will be ignored.

pub fn seal_suggestions(&mut self) -> &mut Diag

Prevent new suggestions from being added to this diagnostic.

Suggestions added before the call to .seal_suggestions() will be preserved and new suggestions will be ignored.

pub fn span_suggestion( &mut self, span: Span, msg: impl Into<DiagMsg>, suggestion: impl Into<DiagMsg>, applicability: Applicability, ) -> &mut Diag

Prints out a message with a suggested edit of the code.

In case of short messages and a simple suggestion, rustc displays it as a label:

try adding parentheses: `(tup.0).1`

The message

• should not end in any punctuation (a : is added automatically)
• should not be a question (avoid language like “did you mean”)
• should not contain any phrases like “the following”, “as shown”, etc.
• may look like “to do xyz, use” or “to do xyz, use abc”
• may contain a name of a function, variable, or type, but not whole expressions

See CodeSuggestion for more information.

pub fn span_suggestion_with_style( &mut self, span: Span, msg: impl Into<DiagMsg>, suggestion: impl Into<DiagMsg>, applicability: Applicability, style: SuggestionStyle, ) -> &mut Diag

Diag::span_suggestion() but you can set the SuggestionStyle.

pub fn multipart_suggestion( &mut self, msg: impl Into<DiagMsg>, substitutions: Vec<(Span, DiagMsg)>, applicability: Applicability, ) -> &mut Diag

Show a suggestion that has multiple parts to it. In other words, multiple changes need to be applied as part of this suggestion.

pub fn multipart_suggestion_with_style( &mut self, msg: impl Into<DiagMsg>, substitutions: Vec<(Span, DiagMsg)>, applicability: Applicability, style: SuggestionStyle, ) -> &mut Diag

Diag::multipart_suggestion() but you can set the SuggestionStyle.

Trait Implementations

impl Clone for Diag

fn clone(&self) -> Diag

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Diag

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Hash for Diag

fn hash<H>(&self, state: &mut H)

where H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Diag

fn eq(&self, other: &Diag) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.