Struct Value

pub struct Value<T = ()> {
    pub value: ValueDef<T>,
    pub context: T,
}

Value holds a representation of some value that has been decoded, as well as some arbitrary context.

Not all SCALE encoded types have an similar-named value; for instance, the values corresponding to sequence, array and composite types can all be represented with Composite. Only enough information is preserved here to to be able to encode and decode SCALE bytes with a known type to and from Values losslessly.

Fields

value: ValueDef<T>

The shape and associated data for this Value

context: T

Some additional arbitrary context that can be associated with a value.

Implementations

impl Value

pub fn named_composite<S, Vals>(vals: Vals) -> Value

where S: Into<String>, Vals: IntoIterator<Item = (S, Value)>,

Construct a named composite type from any type which produces a tuple of keys and values when iterated over.

pub fn unnamed_composite<Vals>(vals: Vals) -> Value

where Vals: IntoIterator<Item = Value>,

Construct an unnamed composite type from any type which produces values when iterated over.

pub fn variant<S>(name: S, values: Composite<()>) -> Value

where S: Into<String>,

Create a new variant value without additional context.

pub fn named_variant<S, F, Vals>(name: S, fields: Vals) -> Value

where S: Into<String>, F: Into<String>, Vals: IntoIterator<Item = (F, Value)>,

Create a new variant value with named fields and without additional context.

pub fn unnamed_variant<S, Vals>(name: S, fields: Vals) -> Value

where S: Into<String>, Vals: IntoIterator<Item = Value>,

Create a new variant value with tuple-like fields and without additional context.

pub fn bit_sequence(bits: Bits) -> Value

Create a new bit sequence value without additional context.

pub fn primitive(primitive: Primitive) -> Value

Create a new primitive value without additional context.

pub fn string<S>(val: S) -> Value

where S: Into<String>,

Create a new string value without additional context.

pub fn bool(val: bool) -> Value

Create a new boolean value without additional context.

pub fn char(val: char) -> Value

Create a new char without additional context.

pub fn u128(val: u128) -> Value

Create a new unsigned integer without additional context.

pub fn i128(val: i128) -> Value

Create a new signed integer without additional context.

pub fn from_bytes(bytes: impl AsRef<[u8]>) -> Value

Create a new Value from a set of bytes; useful for converting things like AccountIds.

impl Value

pub fn without_context(value: ValueDef<()>) -> Value

Create a new value with no associated context.

impl<T> Value<T>

pub fn with_context(value: ValueDef<T>, context: T) -> Value<T>

Create a new value with some associated context.

pub fn remove_context(self) -> Value

Remove the context.

pub fn map_context<F, U>(self, f: F) -> Value<U>

where F: Clone + FnMut(T) -> U,

Map the context to some different type.

pub fn as_bool(&self) -> Option<bool>

If the value is a boolean value, return it.

pub fn as_char(&self) -> Option<char>

If the value is a char, return it.

pub fn as_u128(&self) -> Option<u128>

If the value is a u128, return it.

pub fn as_i128(&self) -> Option<i128>

If the value is an i128, return it.

pub fn as_str(&self) -> Option<&str>

If the value is a string, return it.

Trait Implementations

impl<Ctx> At<Ctx> for Value<Ctx>

fn at<L>(&self, loc: L) -> Option<&Value<Ctx>>

where L: AsLocation,

Index into a value, returning a reference to the value if one exists, or None if not.

impl<T> Clone for Value<T>

where T: Clone,

fn clone(&self) -> Value<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> Debug for Value<T>

where T: Debug,

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

Formats the value using the given formatter.

impl<T> Display for Value<T>

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

Formats the value using the given formatter.

impl<T> EncodeAsFields for Value<T>

fn encode_as_fields_to<R>( &self, fields: &mut dyn FieldIter<'_, <R as TypeResolver>::TypeId, Item = Field<'_, <R as TypeResolver>::TypeId>>, types: &R, out: &mut Vec<u8>, ) -> Result<(), Error>

where R: TypeResolver,

Given some fields describing the shape of a type, attempt to encode to that shape.

fn encode_as_fields<R>( &self, fields: &mut dyn FieldIter<'_, <R as TypeResolver>::TypeId, Item = Field<'_, <R as TypeResolver>::TypeId>>, types: &R, ) -> Result<Vec<u8>, Error>

where R: TypeResolver,

This is a helper function which internally calls EncodeAsFields::encode_as_fields_to. Prefer to implement that instead.

impl<T> EncodeAsType for Value<T>

fn encode_as_type_to<R>( &self, type_id: <R as TypeResolver>::TypeId, types: &R, out: &mut Vec<u8>, ) -> Result<(), Error>

where R: TypeResolver,

Given some type_id, types, a context and some output target for the SCALE encoded bytes, attempt to SCALE encode the current value into the type given by type_id.

fn encode_as_type<R>( &self, type_id: <R as TypeResolver>::TypeId, types: &R, ) -> Result<Vec<u8>, Error>

where R: TypeResolver,

This is a helper function which internally calls EncodeAsType::encode_as_type_to. Prefer to implement that instead.

impl From<&str> for Value

fn from(val: &str) -> Value

Converts to this type from the input type.

impl From<Bits> for Value

fn from(val: Bits) -> Value

Converts to this type from the input type.

impl From<Composite<()>> for Value

fn from(val: Composite<()>) -> Value

Converts to this type from the input type.

impl From<String> for Value

fn from(val: String) -> Value

Converts to this type from the input type.

impl From<Variant<()>> for Value

fn from(val: Variant<()>) -> Value

Converts to this type from the input type.

impl<K, V> From<Vec<(K, V)>> for Value

where K: Into<String>, V: Into<Value>,

fn from(vals: Vec<(K, V)>) -> Value

Converts to this type from the input type.

impl<V> From<Vec<V>> for Value

where V: Into<Value>,

fn from(vals: Vec<V>) -> Value

Converts to this type from the input type.

impl From<bool> for Value

fn from(val: bool) -> Value

Converts to this type from the input type.

impl From<char> for Value

fn from(val: char) -> Value

Converts to this type from the input type.

impl From<i128> for Value

fn from(val: i128) -> Value

Converts to this type from the input type.

impl From<i16> for Value

fn from(val: i16) -> Value

Converts to this type from the input type.

impl From<i32> for Value

fn from(val: i32) -> Value

Converts to this type from the input type.

impl From<i64> for Value

fn from(val: i64) -> Value

Converts to this type from the input type.

impl From<i8> for Value

fn from(val: i8) -> Value

Converts to this type from the input type.

impl From<isize> for Value

fn from(val: isize) -> Value

Converts to this type from the input type.

impl From<u128> for Value

fn from(val: u128) -> Value

Converts to this type from the input type.

impl From<u16> for Value

fn from(val: u16) -> Value

Converts to this type from the input type.

impl From<u32> for Value

fn from(val: u32) -> Value

Converts to this type from the input type.

impl From<u64> for Value

fn from(val: u64) -> Value

Converts to this type from the input type.

impl From<u8> for Value

fn from(val: u8) -> Value

Converts to this type from the input type.

impl From<usize> for Value

fn from(val: usize) -> Value

Converts to this type from the input type.

impl IntoVisitor for Value

type AnyVisitor<R: TypeResolver> = VisitorWithCrateError<DecodeValueVisitor<R, EmptyContext>>

The visitor type used to decode SCALE encoded bytes to Self.

fn into_visitor<R>() -> <Value as IntoVisitor>::AnyVisitor<R>

where R: TypeResolver,

A means of obtaining this visitor.

impl<T> PartialEq for Value<T>

where T: PartialEq,

fn eq(&self, other: &Value<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T> Eq for Value<T>

where T: Eq,

impl<T> StructuralPartialEq for Value<T>