flams_router_vscode::server_fn::inventory::core::fmt

Trait Display

1.6.0 · Source

pub trait Display {
    // Required method
    fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>;
}

Expand description

Format trait for an empty format, {}.

Implementing this trait for a type will automatically implement the ToString trait for the type, allowing the usage of the .to_string() method. Prefer implementing the Display trait for a type, rather than ToString.

Display is similar to Debug, but Display is for user-facing output, and so cannot be derived.

For more information on formatters, see the module-level documentation.

§Completeness and parseability

Display for a type might not necessarily be a lossless or complete representation of the type. It may omit internal state, precision, or other information the type does not consider important for user-facing output, as determined by the type. As such, the output of Display might not be possible to parse, and even if it is, the result of parsing might not exactly match the original value.

However, if a type has a lossless Display implementation whose output is meant to be conveniently machine-parseable and not just meant for human consumption, then the type may wish to accept the same format in FromStr, and document that usage. Having both Display and FromStr implementations where the result of Display cannot be parsed with FromStr may surprise users.

§Internationalization

Because a type can only have one Display implementation, it is often preferable to only implement Display when there is a single most “obvious” way that values can be formatted as text. This could mean formatting according to the “invariant” culture and “undefined” locale, or it could mean that the type display is designed for a specific culture/locale, such as developer logs.

If not all values have a justifiably canonical textual format or if you want to support alternative formats not covered by the standard set of possible formatting traits, the most flexible approach is display adapters: methods like str::escape_default or Path::display which create a wrapper implementing Display to output the specific display format.

§Examples

Implementing Display on a type:

use std::fmt;

struct Point {
    x: i32,
    y: i32,
}

impl fmt::Display for Point {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "({}, {})", self.x, self.y)
    }
}

let origin = Point { x: 0, y: 0 };

assert_eq!(format!("The origin is: {origin}"), "The origin is: (0, 0)");

Required Methods§

1.0.0 · Source

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

Formats the value using the given formatter.

§Errors

This function should return Err if, and only if, the provided Formatter returns Err. String formatting is considered an infallible operation; this function only returns a Result because writing to the underlying stream might fail and it must provide a way to propagate the fact that an error has occurred back up the stack.

§Examples

use std::fmt;

struct Position {
    longitude: f32,
    latitude: f32,
}

impl fmt::Display for Position {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "({}, {})", self.longitude, self.latitude)
    }
}

assert_eq!(
    "(1.987, 2.983)",
    format!("{}", Position { longitude: 1.987, latitude: 2.983, }),
);

Trait DisplayCopy item path

§Completeness and parseability

§Internationalization

§Examples

Required Methods§

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

§Errors

§Examples

Trait Implementations§

impl<'v, 'u> From<&'v &'u dyn Display> for ValueBag<'v>where 'u: 'v,

fn from(v: &'v &'u dyn Display) -> ValueBag<'v>

impl<'v> From<&'v dyn Display> for ValueBag<'v>

fn from(v: &'v dyn Display) -> ValueBag<'v>

Implementors§

impl Display for UserError

impl Display for LoginError

impl Display for OAuthError

impl Display for flams_git::gl::Err

impl Display for ArgMode

impl Display for flams_ontology::content::terms::Term

impl Display for Var

impl Display for FTMLKey

impl Display for flams_ontology::languages::Language

impl Display for PresentationError

impl Display for ParagraphKind

impl Display for CognitiveDimension

impl Display for SectionLevel

impl Display for ContentURI

impl Display for ContentURIRef<'_>

impl Display for URI

impl Display for URIRef<'_>

impl Display for URIParseError

impl Display for NarrativeURI

impl Display for NarrativeURIRef<'_>

impl Display for TermURI

impl Display for TermURIRef<'_>

impl Display for LoginState

impl Display for QueryError

impl Display for QueueName

impl Display for CowStr

impl Display for LogLevel

impl Display for FromToBytesCodecError

impl Display for FromFormDataError

impl Display for flams_router_vscode::FromUtf8Error

impl Display for ServerFnErrorErr

impl Display for LeptosConfigError

impl Display for MultipartRejection

impl Display for flams_router_vscode::server_fn::axum_export::extract::path::ErrorKind

impl Display for BytesRejection

impl Display for ExtensionRejection

impl Display for FailedToBufferBody

impl Display for FormRejection

impl Display for JsonRejection

impl Display for MatchedPathRejection

impl Display for PathRejection

impl Display for QueryRejection

impl Display for RawFormRejection

impl Display for RawPathParamsRejection

impl Display for StringRejection

impl Display for WebSocketUpgradeRejection

impl Display for AsciiChar

impl Display for Infallible

impl Display for FromBytesWithNulError

impl Display for IpAddr

impl Display for SocketAddr

impl Display for flams_router_vscode::server_fn::inventory::core::slice::GetDisjointMutError

impl Display for proc_macro::TokenTree

impl Display for VarError

impl Display for std::fs::TryLockError

impl Display for std::io::error::ErrorKind

impl Display for std::sync::mpsc::RecvTimeoutError

impl Display for std::sync::mpsc::TryRecvError

impl Display for bincode::error::DecodeError

impl Display for bincode::error::EncodeError

impl Display for RoundingError

impl Display for chrono::weekday::Weekday

impl Display for ObjectType

impl Display for ReferenceType

impl Display for hex::error::FromHexError

impl Display for IpNet

Trait Display

impl<'v, 'u> From<&'v &'u dyn Display> for ValueBag<'v>
where 'u: 'v,