Enum rustc_errors::DiagnosticMessage

pub enum DiagnosticMessage {
    Str(Cow<'static, str>),
    Eager(Cow<'static, str>),
    FluentIdentifier(Cow<'static, str>, Option<Cow<'static, str>>),
}

Abstraction over a message in a diagnostic to support both translatable and non-translatable diagnostic messages.

Intended to be removed once diagnostics are entirely translatable.

Variants

Str(Cow<'static, str>)

Non-translatable diagnostic message.

Eager(Cow<'static, str>)

Translatable message which has already been translated eagerly.

Some diagnostics have repeated subdiagnostics where the same interpolated variables would be instantiated multiple times with different values. As translation normally happens immediately prior to emission, after the diagnostic and subdiagnostic derive logic has run, the setting of diagnostic arguments in the derived code will overwrite previous variable values and only the final value will be set when translation occurs - resulting in incorrect diagnostics. Eager translation results in translation for a subdiagnostic happening immediately after the subdiagnostic derive’s logic has been run. This variant stores messages which have been translated eagerly.

FluentIdentifier(Cow<'static, str>, Option<Cow<'static, str>>)

Identifier for a Fluent message (with optional attribute) corresponding to the diagnostic message.

https://projectfluent.org/fluent/guide/hello.html https://projectfluent.org/fluent/guide/attributes.html

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 48 bytes

Size for each variant:

• Str: 32 bytes
• Eager: 32 bytes
• FluentIdentifier: 48 bytes