Struct starlark::errors::Diagnostic

pub struct Diagnostic {
    pub message: Error,
    pub span: Option<FileSpan>,
    pub call_stack: CallStack,
}

An error plus its origination location and call stack.

The underlying message is an anyhow::Error. The Diagnostic structure itself usually stored within an anyhow::Error.

Fields

message: Error

Underlying error for the Diagnostic. Should never be of type Diagnostic itself.

span: Option<FileSpan>

Location where the error originated.

call_stack: CallStack

Call stack where the error originated.

Implementations

impl Diagnostic

pub fn modify(err: Error, f: impl FnOnce(&mut Diagnostic)) -> Error

Modify an error by attaching diagnostic information to it - e.g. span/call_stack. If given an anyhow::Error which is a Diagnostic, it will add the information to the existing Diagnostic. If not, it will wrap the error in Diagnostic.

pub fn set_call_stack(&mut self, call_stack: impl FnOnce() -> CallStack)

Set the Diagnostic::call_stack field, unless it’s already been set.

pub fn eprint(err: &Error)

Print an error to the stderr stream. If the error is a Diagnostic it will use color-codes when printing.

Note that this function doesn’t print any context information if the error is a Diagnostic, so you might prefer to use eprintln!("{:#}"), err) if you suspect there is useful context (although you won’t get pretty colors).

Trait Implementations

impl Debug for Diagnostic

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

Formats the value using the given formatter.

impl Display for Diagnostic

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

Formats the value using the given formatter.

impl Error for Diagnostic

fn source(&self) -> Option<&(dyn Error + 'static)>

The lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0: use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0: replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, demand: &mut Demand<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type based access to context intended for error reports.