Trait params::FromValue

pub trait FromValue: Sized {
    fn from_value(value: &Value) -> Option<Self>;
}

An interface for converting from Value variants.

Required Methods

fn from_value(value: &Value) -> Option<Self>

Returns Some if the conversion was successful, None otherwise.

Implementations on Foreign Types

impl FromValue for u8

Casts from any of the numeric variants (I64, U64, F64) and converts from the String variant using std::str::FromStr.

fn from_value(value: &Value) -> Option<u8>

impl FromValue for u16

Casts from any of the numeric variants (I64, U64, F64) and converts from the String variant using std::str::FromStr.

fn from_value(value: &Value) -> Option<u16>

impl FromValue for u32

Casts from any of the numeric variants (I64, U64, F64) and converts from the String variant using std::str::FromStr.

fn from_value(value: &Value) -> Option<u32>

impl FromValue for u64

Casts from any of the numeric variants (I64, U64, F64) and converts from the String variant using std::str::FromStr.

fn from_value(value: &Value) -> Option<u64>

impl FromValue for usize

Casts from any of the numeric variants (I64, U64, F64) and converts from the String variant using std::str::FromStr.

fn from_value(value: &Value) -> Option<usize>

impl FromValue for i8

Casts from any of the numeric variants (I64, U64, F64) and converts from the String variant using std::str::FromStr.

fn from_value(value: &Value) -> Option<i8>

impl FromValue for i16

Casts from any of the numeric variants (I64, U64, F64) and converts from the String variant using std::str::FromStr.

fn from_value(value: &Value) -> Option<i16>

impl FromValue for i32

Casts from any of the numeric variants (I64, U64, F64) and converts from the String variant using std::str::FromStr.

fn from_value(value: &Value) -> Option<i32>

impl FromValue for i64

Casts from any of the numeric variants (I64, U64, F64) and converts from the String variant using std::str::FromStr.

fn from_value(value: &Value) -> Option<i64>

impl FromValue for isize

Casts from any of the numeric variants (I64, U64, F64) and converts from the String variant using std::str::FromStr.

fn from_value(value: &Value) -> Option<isize>

impl FromValue for f32

Casts from any of the numeric variants (I64, U64, F64) and converts from the String variant using std::str::FromStr.

fn from_value(value: &Value) -> Option<f32>

impl FromValue for f64

Casts from any of the numeric variants (I64, U64, F64) and converts from the String variant using std::str::FromStr.

fn from_value(value: &Value) -> Option<f64>

impl FromValue for String

Converts from any of the flat variants (Null, Boolean, I64, U64, F64, String).

Null is converted to an empty string. All other variants make use of std::string::ToString, so the respective Display formatted results are used. For example, Boolean values are converted into either "false" or "true".

fn from_value(value: &Value) -> Option<String>

impl FromValue for bool

Converts from common representations of false and true.

• Boolean values are mapped directly.
• I64 and U64 map 0 and 1 to false and true respectively.
• String maps "0", "f", "F", "false", "FALSE", "off", and "OFF" to false.
• String maps "1", "t", "T", "true", "TRUE", "on", and "ON" to true.
• All other variants return None.

fn from_value(value: &Value) -> Option<bool>

impl<T: FromValue> FromValue for Option<T>

Converts the Null variant to None and delegates any other variants to T::from_value.

fn from_value(value: &Value) -> Option<Option<T>>

impl<T: FromValue> FromValue for Vec<T>

Converts from Array variant.

fn from_value(value: &Value) -> Option<Vec<T>>

impl<T: FromValue> FromValue for BTreeMap<String, T>

Converts using Map::to_strict_map if the variant is Map, returns None otherwise.

fn from_value(value: &Value) -> Option<BTreeMap<String, T>>

Implementors

• impl FromValue for Value
• impl FromValue for File