Struct INumber 

pub struct INumber(/* private fields */);

The INumber type represents a JSON number. It is decoupled from any specific representation, and internally uses several. There is no way to determine the internal representation: instead the caller is expected to convert the number using one of the fallible to_xxx functions and handle the cases where the number does not convert to the desired type.

Special floating point values (eg. NaN, Infinity, etc.) cannot be stored within an INumber.

Whilst INumber does not consider 2.0 and 2 to be different numbers (ie. they will compare equal) it does allow you to distinguish them using the method INumber::has_decimal_point(). That said, calling to_i32 on 2.0 will succeed with the value 2.

Small numbers — integers and short decimals alike — are stored inline without a heap allocation. Larger integers (i64/u64) and floating point values that are not short decimals are stored behind a pointer.

Implementations

impl INumber

pub fn zero() -> Self

Returns the number zero (without a decimal point). Does not allocate.

pub fn one() -> Self

Returns the number one (without a decimal point). Does not allocate.

pub fn to_i64(&self) -> Option<i64>

Converts this number to an i64 if it can be represented exactly.

pub fn to_u64(&self) -> Option<u64>

Converts this number to a u64 if it can be represented exactly.

pub fn to_f64(&self) -> Option<f64>

Converts this number to an f64 if it can be represented exactly.

pub fn to_f32(&self) -> Option<f32>

Converts this number to an f32 if it can be represented exactly.

pub fn to_i32(&self) -> Option<i32>

Converts this number to an i32 if it can be represented exactly.

pub fn to_u32(&self) -> Option<u32>

Converts this number to a u32 if it can be represented exactly.

pub fn to_isize(&self) -> Option<isize>

Converts this number to an isize if it can be represented exactly.

pub fn to_usize(&self) -> Option<usize>

Converts this number to a usize if it can be represented exactly.

pub fn to_f64_lossy(&self) -> f64

Converts this number to an f64, potentially losing precision in the process.

pub fn to_f32_lossy(&self) -> f32

Converts this number to an f32, potentially losing precision in the process.

pub fn has_decimal_point(&self) -> bool

This allows distinguishing between 1.0 and 1 in the original JSON. Numeric operations will otherwise treat these two values as equivalent.

Trait Implementations

impl AsMut<IValue> for INumber

fn as_mut(&mut self) -> &mut IValue

Converts this type into a mutable reference of the (usually inferred) input type.

impl AsRef<IValue> for INumber

fn as_ref(&self) -> &IValue

Converts this type into a shared reference of the (usually inferred) input type.

impl Borrow<IValue> for INumber

fn borrow(&self) -> &IValue

Immutably borrows from an owned value.

impl BorrowMut<IValue> for INumber

fn borrow_mut(&mut self) -> &mut IValue

Mutably borrows from an owned value.

impl Clone for INumber

fn clone(&self) -> INumber

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for INumber

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

Formats the value using the given formatter.

impl Default for INumber

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for INumber

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<'de> Deserializer<'de> for &'de INumber

type Error = Error

The error type that can be returned if some error occurs during deserialization.

fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Error>

where V: Visitor<'de>,

Require the Deserializer to figure out how to drive the visitor based on what data type is in the input.

fn deserialize_newtype_struct<V>( self, _name: &'static str, visitor: V, ) -> Result<V::Value, Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a newtype struct with a particular name.

fn deserialize_bool<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a bool value.

fn deserialize_i8<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting an i8 value.

fn deserialize_i16<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting an i16 value.

fn deserialize_i32<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting an i32 value.

fn deserialize_i64<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting an i64 value.

fn deserialize_i128<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting an i128 value.

fn deserialize_u8<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a u8 value.

fn deserialize_u16<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a u16 value.

fn deserialize_u32<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a u32 value.

fn deserialize_u64<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a u64 value.

fn deserialize_u128<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting an u128 value.

fn deserialize_f32<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a f32 value.

fn deserialize_f64<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a f64 value.

fn deserialize_char<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a char value.

fn deserialize_str<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a string value and does not benefit from taking ownership of buffered data owned by the Deserializer.

fn deserialize_string<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a string value and would benefit from taking ownership of buffered data owned by the Deserializer.

fn deserialize_bytes<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a byte array and does not benefit from taking ownership of buffered data owned by the Deserializer.

fn deserialize_byte_buf<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a byte array and would benefit from taking ownership of buffered data owned by the Deserializer.

fn deserialize_option<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting an optional value.

fn deserialize_unit<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a unit value.

fn deserialize_unit_struct<V>( self, name: &'static str, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a unit struct with a particular name.

fn deserialize_seq<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a sequence of values.

fn deserialize_tuple<V>( self, len: usize, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a sequence of values and knows how many values there are without looking at the serialized data.

fn deserialize_tuple_struct<V>( self, name: &'static str, len: usize, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a tuple struct with a particular name and number of fields.

fn deserialize_map<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a map of key-value pairs.

fn deserialize_struct<V>( self, name: &'static str, fields: &'static [&'static str], visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting a struct with a particular name and fields.

fn deserialize_enum<V>( self, name: &'static str, variants: &'static [&'static str], visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting an enum value with a particular name and possible variants.

fn deserialize_identifier<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type is expecting the name of a struct field or the discriminant of an enum variant.

fn deserialize_ignored_any<V>( self, visitor: V, ) -> Result<V::Value, <Self as Deserializer<'de>>::Error>

where V: Visitor<'de>,

Hint that the Deserialize type needs to deserialize a value whose type doesn’t matter because it is ignored.

fn is_human_readable(&self) -> bool

Determine whether Deserialize implementations should expect to deserialize their human-readable form.

impl Eq for INumber

impl From<INumber> for IValue

fn from(other: INumber) -> Self

Converts to this type from the input type.

impl From<INumber> for Number

Converts an INumber into a serde_json::Number.

Conversion may be lossy if the number is not exactly representable as a serde_json::Number. The exact behaviour in that case (e.g. rounding) is not guaranteed to be stable across versions.

fn from(n: INumber) -> Self

Converts to this type from the input type.

impl From<Number> for INumber

Converts a serde_json::Number into an INumber.

Conversion may be lossy if the number is not exactly representable as an INumber. The exact behaviour in that case (e.g. clamping an out-of-range magnitude) is not guaranteed to be stable across versions.

fn from(n: Number) -> Self

Converts to this type from the input type.

impl From<i8> for INumber

fn from(v: i8) -> Self

Converts to this type from the input type.

impl From<i16> for INumber

fn from(v: i16) -> Self

Converts to this type from the input type.

impl From<i32> for INumber

fn from(v: i32) -> Self

Converts to this type from the input type.

impl From<i64> for INumber

fn from(v: i64) -> Self

Converts to this type from the input type.

impl From<isize> for INumber

fn from(v: isize) -> Self

Converts to this type from the input type.

impl From<u8> for INumber

fn from(v: u8) -> Self

Converts to this type from the input type.

impl From<u16> for INumber

fn from(v: u16) -> Self

Converts to this type from the input type.

impl From<u32> for INumber

fn from(v: u32) -> Self

Converts to this type from the input type.

impl From<u64> for INumber

fn from(v: u64) -> Self

Converts to this type from the input type.

impl From<usize> for INumber

fn from(v: usize) -> Self

Converts to this type from the input type.

impl FromStr for INumber

Parses a JSON number from its textual form, exactly as the JSON grammar defines it (see https://www.json.org/).

A float-shaped number is parsed to the nearest f64 (as deserializing through serde_json would), while a plain in-range integer keeps its exact integer representation (no decimal point).

With the arbitrary_precision feature this instead preserves the exact decimal value where it fits: "0.1" becomes the exact 1 * 10^-1 rather than the f64 approximation — and thus a different value from the f64 0.1 — falling back to the nearest f64 only when the value is too large or too precise to hold exactly.

Examples

let n: INumber = "1.5".parse().unwrap();
assert_eq!(n.to_f64(), Some(1.5));
assert!(n.has_decimal_point());

let n: INumber = "-42".parse().unwrap();
assert_eq!(n.to_i64(), Some(-42));
assert!(!n.has_decimal_point());

// Invalid JSON numbers are rejected (leading zero, bare '+', trailing '.').
assert!("01".parse::<INumber>().is_err());
assert!("+1".parse::<INumber>().is_err());
assert!("1.".parse::<INumber>().is_err());

type Err = ParseNumberError

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Hash for INumber

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for INumber

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for INumber

fn eq(&self, other: &Self) -> bool

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for INumber

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serialize for INumber

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl<'a> TryFrom<&'a IValue> for &'a INumber

type Error = ()

The type returned in the event of a conversion error.

fn try_from(other: &'a IValue) -> Result<Self, ()>

Performs the conversion.

impl<'a> TryFrom<&'a mut IValue> for &'a mut INumber

type Error = ()

The type returned in the event of a conversion error.

fn try_from(other: &'a mut IValue) -> Result<Self, ()>

Performs the conversion.

impl TryFrom<IValue> for INumber

type Error = IValue

The type returned in the event of a conversion error.

fn try_from(other: IValue) -> Result<Self, IValue>

Performs the conversion.

impl TryFrom<f32> for INumber

type Error = ()

The type returned in the event of a conversion error.

fn try_from(v: f32) -> Result<Self, ()>

Performs the conversion.

impl TryFrom<f64> for INumber

type Error = ()

The type returned in the event of a conversion error.

fn try_from(v: f64) -> Result<Self, ()>

Performs the conversion.