Struct Diagnostic

pub struct Diagnostic {
    pub kind: DiagnosticKind,
    pub message: String,
    pub span: Option<Span>,
    pub notes: Vec<DiagnosticNote>,
    pub helps: Vec<DiagnosticHelp>,
}

Additional contextual information intended for end users, to help them understand what went wrong by providing human-readable messages, and locations in the source query that relate to the error in some way.

You can think of a single Diagnostic as a single “block” of output from rustc. i.e. either an error or a warning, optionally with some notes and help messages.

Example:

let span = Some(Span {
    start: Location{ line: 2, column: 1 },
    end: Location{ line: 4, column: 15 }
});
let diagnostic = Diagnostic::new_error("Something went wrong", span)
    .with_help("Have you tried turning it on and off again?", None);

Fields

kind: DiagnosticKind

message: String

span: Option<Span>

notes: Vec<DiagnosticNote>

helps: Vec<DiagnosticHelp>

Implementations

impl Diagnostic

pub fn new_error(message: impl Into<String>, span: Option<Span>) -> Diagnostic

Creates a new Diagnostic for a fatal error that prevents the SQL query from being planned and executed. Optionally takes in a Span to describe the location in the source code that caused the error, should be provided when available.

pub fn new_warning(message: impl Into<String>, span: Option<Span>) -> Diagnostic

Creates a new Diagnostic for a NON-fatal warning, such as a performance problem, or possible cause for undesired results. Optionally takes in a Span to describe the location in the source code that caused the error, should be provided when available.

pub fn add_note(&mut self, message: impl Into<String>, span: Option<Span>)

Adds a “note” to the Diagnostic, which can have zero or many. A “note” helps contextualize the error and helps the end user understand why it occurred. It can refer to an arbitrary location in the SQL query, or to no location.

pub fn add_help(&mut self, message: impl Into<String>, span: Option<Span>)

Adds a “help” to the Diagnostic, which can have zero or many. A “help” helps the user understand how they might fix the error or warning. It can refer to an arbitrary location in the SQL query, or to no location.

pub fn with_note( self, message: impl Into<String>, span: Option<Span>, ) -> Diagnostic

Like Diagnostic::add_note, but returns self to allow chaining.

pub fn with_help( self, message: impl Into<String>, span: Option<Span>, ) -> Diagnostic

Like Diagnostic::add_help, but returns self to allow chaining.

Trait Implementations

impl Clone for Diagnostic

fn clone(&self) -> Diagnostic

Returns a copy 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<(), Error>

Formats the value using the given formatter.