Enum egglang::expression::Value

pub enum Value {
    Nil,
    Number(OrderedFloat<f32>),
    Boolean(bool),
    String(ArcStr),
    Function(usize),
    Object(usize),
}

A primitive in Egg; can be a number, boolean, string, function, or an object.

Most primitives are immutable, to mutate create a new value. Objects are mutable, and can be modified in-place. Functions are technically also mutable as they are stored by reference, but there’s no actual built-in path to mutation.

Some Rust primitives can be converted into a Value using the From trait.

use egglang::expression::Value;

let number: Value = 42.0.into();
let string: Value = "Hello, World!".into();
let boolean: Value = true.into();
let nil: Value = ().into();

// Option<T: Into<Value>> can be converted into Value
assert_eq!(Value::Nil, None::<f32>.into());
let five: Value = Some(5.0).into();
assert_eq!(Value::from(5.0), five);

Variants

Nil

Represents the absence of a value.

Number(OrderedFloat<f32>)

A 32-bit floating-point number.

Boolean(bool)

A boolean value.

String(ArcStr)

Atomically reference-counted string.

Function(usize)

A function definition. Stores a index to the function in the scope.

Object(usize)

An object. Stores a index to the object in the scope.

Trait Implementations

impl Clone for Value

fn clone(&self) -> Value

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Value

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

Formats the value using the given formatter.

impl Display for Value

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

Formats the value using the given formatter.

impl From<&str> for Value

fn from(val: &str) -> Self

Converts to this type from the input type.

impl From<()> for Value

fn from(_: ()) -> Self

Converts to this type from the input type.

impl From<ArcStr> for Value

fn from(val: ArcStr) -> Self

Converts to this type from the input type.

impl<T: Into<Value>> From<Option<T>> for Value

fn from(val: Option<T>) -> Self

Converts to this type from the input type.

impl From<bool> for Value

fn from(val: bool) -> Self

Converts to this type from the input type.

impl From<f32> for Value

fn from(val: f32) -> Self

Converts to this type from the input type.

impl Ord for Value

fn cmp(&self, other: &Value) -> 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 + PartialOrd,

Restrict a value to a certain interval.

impl PartialEq for Value

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

This method tests for self and other values to be equal, and is used by ==.

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

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

impl PartialOrd for Value

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

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

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

This method tests less than (for self and other) and is used by the < operator.

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

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

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

This method tests greater than (for self and other) and is used by the > operator.

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

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

impl Eq for Value

impl StructuralPartialEq for Value