Enum Val 

pub enum Val {
    Cst(i64),
    Sym(SmolStr),
    Tup(RcVal, RcVal),
    Clo(Env, RcExp),
    Nil,
    Code(RcExp),
    Cell(usize),
}

A runtime value.

Values and expressions are distinct types, unlike base.scm where both are s-expressions. Staged code crosses the divide as Val::Code — an expression tree held as a value — and Exp::Proc carries a value back into an expression.

Variants

Cst(i64)

Integer constant (also the boolean encoding: 0 false, 1 true).

Sym(SmolStr)

Symbol. SmolStr is O(1) clone for strings ≤22 bytes.

Tup(RcVal, RcVal)

Cons cell. Rc<Val> makes car/cdr O(1) — Pink source lists are traversed many times during staging.

Clo(Env, RcExp)

Closure: environment + body. Both are Rc for O(1) clone and ptr_eq in find_fun.

Nil

The empty list, terminating every Val::Tup chain. Note that if does not accept it as a condition — conditions are numbers (or code); test for nil with null?.

Code(RcExp)

Staged code value. Rc<Exp> — shared through the staging machinery.

Cell(usize)

First-class mutable cell — an index into EvalCtx.cells (the per-instance, in-process store: each evaluator owns its own heap, so instances snapshot and compose freely). Identity is the index: eq? compares indices, cell-set! through one alias is visible through all. Cells never fold under staging: lift of a Cell errors, and staged cell ops residualize as operations.

Implementations

impl Val

pub fn short_desc(&self) -> String

Compact description suitable for error messages. Avoids dumping large Val::Code trees — instead reports node count.

This is the form to use in NarjuError::TypeError.actual and similar diagnostic strings. Use display(v) (in eval/mod.rs) or format!("{v}") (via fmt::Display) for user-facing output where the full structure matters.

Trait Implementations

impl Clone for Val

fn clone(&self) -> Val

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Val

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

Formats the value using the given formatter.

impl Display for Val

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

Formats the value using the given formatter.

impl PartialEq for Val

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.