Enum Value 

pub enum Value {
    Number(i64),
    Symbol(String),
    String(String),
    Bool(bool),
    List(Vec<Value>),
    PrecompiledOp {
        op: &'static BuiltinOp,
        op_id: String,
        args: Vec<Value>,
    },
    BuiltinFunction {
        id: String,
        func: fn(&[Value]) -> Result<Value, Error>,
    },
    Function {
        params: Vec<String>,
        body: Box<Value>,
        env: Environment,
    },
    Unspecified,
}

Core AST type in interpreter

Note: PrecompiledOps (optimized s-expressions) don’t equality-compare to dynamically generated unoptimized s-expressions. However, since no expression can return a PrecompiledOp (they’re consumed during evaluation), this is not a concern for user code.

To build an AST, use the ergonomic helper functions:

• val(42) for values, sym("name") for symbols, nil() for empty lists
• val([1, 2, 3]) for homogeneous lists
• val(vec![sym("op"), val(42)]) for mixed lists

Variants

Number(i64)

Numbers (integers only)

Symbol(String)

Symbols (identifiers)

String(String)

String literals

Bool(bool)

Boolean values

List(Vec<Value>)

Lists (including proper and improper lists, empty list represents nil)

PrecompiledOp

Pre-compiled operations with their arguments (optimized during parsing)

Fields

op: &'static BuiltinOp

op_id: String

args: Vec<Value>

BuiltinFunction

Built-in functions (used when called through Symbol, not pre-optimized due to dynamism) Uses id string for equality comparison instead of function pointer

Fields

id: String

func: fn(&[Value]) -> Result<Value, Error>

Function

User-defined functions (params, body, closure env)

Fields

params: Vec<String>

body: Box<Value>

env: Environment

Unspecified

Unspecified values (e.g., return value of define) These values never equal themselves or any other value

Trait Implementations

impl Clone for Value

fn clone(&self) -> Value

Returns a duplicate 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<T: Into<Value> + Clone> From<&[T]> for Value

fn from(slice: &[T]) -> Self

Converts to this type from the input type.

impl From<&str> for Value

fn from(s: &str) -> Self

Converts to this type from the input type.

impl<T: Into<Value>, const N: usize> From<[T; N]> for Value

fn from(arr: [T; N]) -> Self

Converts to this type from the input type.

impl From<String> for Value

fn from(s: String) -> Self

Converts to this type from the input type.

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

fn from(v: Vec<T>) -> Self

Converts to this type from the input type.

impl From<bool> for Value

fn from(b: bool) -> Self

Converts to this type from the input type.

impl From<i16> for Value

fn from(n: i16) -> Self

Converts to this type from the input type.

impl From<i32> for Value

fn from(n: i32) -> Self

Converts to this type from the input type.

impl From<i64> for Value

fn from(n: i64) -> Self

Converts to this type from the input type.

impl From<i8> for Value

fn from(n: i8) -> Self

Converts to this type from the input type.

impl From<u16> for Value

fn from(n: u16) -> Self

Converts to this type from the input type.

impl From<u32> for Value

fn from(n: u32) -> Self

Converts to this type from the input type.

impl From<u8> for Value

fn from(n: u8) -> Self

Converts to this type from the input type.

impl PartialEq for Value

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