Trait scrypto::prelude::Debug

1.0.0 · source ·

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

Expand description

? formatting.

Debug should format the output in a programmer-facing, debugging context.

Generally speaking, you should just derive a Debug implementation.

When used with the alternate format specifier #?, the output is pretty-printed.

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

This trait can be used with #[derive] if all fields implement Debug. When derived for structs, it will use the name of the struct, then {, then a comma-separated list of each field’s name and Debug value, then }. For enums, it will use the name of the variant and, if applicable, (, then the Debug values of the fields, then ).

§Stability

Derived Debug formats are not stable, and so may change with future Rust versions. Additionally, Debug implementations of types provided by the standard library (std, core, alloc, etc.) are not stable, and may also change with future Rust versions.

§Examples

Deriving an implementation:

#[derive(Debug)]
struct Point {
    x: i32,
    y: i32,
}

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

assert_eq!(format!("The origin is: {origin:?}"), "The origin is: Point { x: 0, y: 0 }");

Manually implementing:

use std::fmt;

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

impl fmt::Debug for Point {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_struct("Point")
         .field("x", &self.x)
         .field("y", &self.y)
         .finish()
    }
}

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

assert_eq!(format!("The origin is: {origin:?}"), "The origin is: Point { x: 0, y: 0 }");

There are a number of helper methods on the Formatter struct to help you with manual implementations, such as debug_struct.

Types that do not wish to use the standard suite of debug representations provided by the Formatter trait (debug_struct, debug_tuple, debug_list, debug_set, debug_map) can do something totally custom by manually writing an arbitrary representation to the Formatter.

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

Debug implementations using either derive or the debug builder API on Formatter support pretty-printing using the alternate flag: {:#?}.

Pretty-printing with #?:

#[derive(Debug)]
struct Point {
    x: i32,
    y: i32,
}

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

assert_eq!(format!("The origin is: {origin:#?}"),
"The origin is: Point {
    x: 0,
    y: 0,
}");

Required Methods§

source

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

Formats the value using the given formatter.

§Examples

use std::fmt;

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

impl fmt::Debug for Position {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_tuple("")
         .field(&self.longitude)
         .field(&self.latitude)
         .finish()
    }
}

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

assert_eq!(format!("{position:#?}"), "(
    1.987,
    2.983,
)");

Trait scrypto::prelude::Debug

§Stability

§Examples

Required Methods§

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

§Examples

Implementors§

impl Debug for AddressBech32DecodeError

impl Debug for AddressBech32EncodeError

impl Debug for AttachedModuleId

impl Debug for KeyValueStoreDataSchema

impl Debug for ModuleId

impl Debug for FallToOwner

impl Debug for MetadataConversionError

impl Debug for Proposer

impl Debug for Role

impl Debug for DefaultDepositRule

impl Debug for ResourcePreference

impl Debug for TimePrecisionV1

impl Debug for TimePrecisionV2

impl Debug for BlueprintPartitionType

impl Debug for BlueprintPayloadDef

impl Debug for BlueprintPayloadIdentifier

impl Debug for BlueprintType

impl Debug for FunctionAuth

impl Debug for InputOrOutput

impl Debug for KeyOrValue

impl Debug for MethodAuthTemplate

impl Debug for PartitionDescription

impl Debug for RoleSpecification

impl Debug for SystemInstruction

impl Debug for VmType

impl Debug for AccessRule

impl Debug for AccessRuleNode

impl Debug for GlobalCaller

impl Debug for MethodAccessibility

impl Debug for NonFungibleDataSchema

impl Debug for OwnerRole

impl Debug for OwnerRoleUpdater

impl Debug for ParseNonFungibleGlobalIdError

impl Debug for ProofRule

impl Debug for ResourceError

impl Debug for ResourceFeature

impl Debug for ResourceOrNonFungible

impl Debug for ResourceType

impl Debug for WithdrawStrategy

impl Debug for InstructionOutput

impl Debug for ComponentCastError

impl Debug for ObjectStubHandle

impl Debug for ParseBlsPublicKeyError

impl Debug for ParseBlsSignatureError

impl Debug for ParseEd25519PublicKeyError

impl Debug for ParseEd25519SignatureError

impl Debug for ParseHashError

impl Debug for ParseSecp256k1PublicKeyError

impl Debug for ParseSecp256k1SignatureError

impl Debug for scrypto::crypto::PublicKey

impl Debug for PublicKeyHash

impl Debug for ManifestCustomExtension

impl Debug for ManifestCustomTraversal

impl Debug for ManifestCustomValue

impl Debug for ManifestCustomValueKind

impl Debug for ManifestToRustValueError

impl Debug for RustToManifestValueError

impl Debug for ManifestAddress

impl Debug for ManifestExpression

impl Debug for ManifestNonFungibleLocalId

impl Debug for ManifestNonFungibleLocalIdValidationError

impl Debug for ParseManifestAddressReservationError

impl Debug for ParseManifestBlobRefError

impl Debug for ParseManifestBucketError

impl Debug for ParseManifestDecimalError

impl Debug for ParseManifestExpressionError

impl Debug for ParseManifestPreciseDecimalError

impl Debug for ParseManifestProofError

impl Debug for OwnValidation

impl Debug for ReferenceValidation

impl Debug for ScryptoCustomTraversal

impl Debug for ScryptoCustomTypeKind

impl Debug for ScryptoCustomTypeValidation