Enum EvalTree 

pub enum EvalTree {
    Num(f64),
    Var(String),
    Fun(String, Vec<EvalTree>),
    Add(Vec<EvalTree>),
    Mul(Vec<EvalTree>),
    Pow(Box<EvalTree>, Box<EvalTree>),
}

An owned intermediate representation of a symbolic expression.

Unlike Atom, EvalTree owns all its data and does not depend on an arena. This makes it suitable for multi-pass compilation and optimization.

Variants

Num(f64)

A numeric constant.

Var(String)

A variable reference.

Fun(String, Vec<EvalTree>)

A named function applied to arguments.

Add(Vec<EvalTree>)

A sum of terms.

Mul(Vec<EvalTree>)

A product of factors.

Pow(Box<EvalTree>, Box<EvalTree>)

A power expression: base^exponent.

Implementations

impl EvalTree

pub fn from_atom(atom: Atom<'_>) -> Self

Convert an Atom into an owned EvalTree.

This dissociates the expression from the arena, allowing the compilation pipeline to work without lifetime constraints.

Example

use ocas_atom::AtomArena;
use ocas_eval::EvalTree;

let arena = ocas_core::arena::Arena::new();
let ctx = AtomArena::new(&arena);
let atom = ctx.add(&[ctx.var("x"), ctx.num(2)]);
let tree = EvalTree::from_atom(atom);

pub fn fold_constants(&self) -> EvalTree

Fold constant subtrees and apply algebraic identities.

Rules applied:

• Add: drop 0 terms, sum all-constant terms, collapse single terms
• Mul: absorb 0, drop 1 factors, multiply all-constant factors, collapse single factors
• Pow: x^1 → x, x^0 → 1, Num^Num evaluated
• Fun: builtin functions of all-constant arguments evaluated (external functions are never folded — they may have side effects)

Trait Implementations

impl Clone for EvalTree

fn clone(&self) -> EvalTree

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for EvalTree

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

Formats the value using the given formatter.

impl PartialEq for EvalTree

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for EvalTree