Struct Diagnostic 

pub struct Diagnostic {
    pub code: &'static str,
    pub severity: Severity,
    pub message: String,
    pub file: FileId,
    pub primary: Label,
    pub secondary: Vec<Label>,
    pub notes: Vec<String>,
    pub fix: Option<Fix>,
}

One problem, at one place, with one cause.

Cascades are deliberately not modelled. If a single root cause would produce several diagnostics, the producer is expected to emit one diagnostic with secondary labels instead, because a wall of derived errors buries the line that actually needs editing.

Fields

code: &'static str

Stable identifier, for example DEED1002. Codes are never reused.

severity: Severity

message: String

file: FileId

primary: Label

secondary: Vec<Label>

notes: Vec<String>

fix: Option<Fix>

Implementations

impl Diagnostic

pub fn error( code: &'static str, file: FileId, span: Span, message: impl Into<String>, ) -> Self

pub fn warning( code: &'static str, file: FileId, span: Span, message: impl Into<String>, ) -> Self

pub fn with_primary_label(self, message: impl Into<String>) -> Self

Overrides the primary label, when the underline should say something shorter or more specific than the headline message.

pub fn with_secondary(self, span: Span, message: impl Into<String>) -> Self

pub fn with_secondary_in( self, file: FileId, span: Span, message: impl Into<String>, ) -> Self

The same, about somewhere else.

For the producer that has a span from another module in hand: a precondition failure names a clause in the callee and is filed against the caller, and a postcondition failure is the other way round. Passing the diagnostic’s own file here is harmless and says the same thing as Self::with_secondary.

pub fn with_note(self, note: impl Into<String>) -> Self

pub fn with_fix( self, message: impl Into<String>, span: Span, replacement: impl Into<String>, applicability: Applicability, ) -> Self

pub fn with_edits( self, message: impl Into<String>, edits: Vec<SuggestedEdit>, applicability: Applicability, ) -> Self

A fix made of several edits that only mean anything together.

One edit is the ordinary case, which is what Self::with_fix is for. This is for a repair that has to wrap something: turning n as String into to_string(n) is an insertion in front of the value and a replacement behind it, and either half on its own leaves the line worse than it was found. Whoever applies a fix has to take all of it or none.

The edits are given in the order they appear in the file.

pub fn is_error(&self) -> bool

Trait Implementations

impl Clone for Diagnostic

fn clone(&self) -> Diagnostic

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Diagnostic

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

Formats the value using the given formatter.