Struct SymbolicDagBuilder 

pub struct SymbolicDagBuilder<F: Field> {
    pub expr_to_idx: FxHashMap<*const SymbolicExpression<F>, usize>,
    pub node_to_idx: FxHashMap<SymbolicExpressionNode<F>, usize>,
    pub nodes: Vec<SymbolicExpressionNode<F>>,
}

Builder for constructing a symbolic expression DAG with structural deduplication and algebraic simplifications.

Two caches are used:

• expr_to_idx: Fast path for expressions with the same Arc pointer
• node_to_idx: Structural deduplication - catches identical nodes with different Arc pointers

Algebraic simplifications performed:

• Constant folding: a + b → c, a - b → c, a * b → c, -a → c (for constants a,b)
• x + 0 → x, 0 + x → x
• x - 0 → x
• x * 1 → x, 1 * x → x
• x * 0 → 0, 0 * x → 0
• x + (-y) → x - y
• x - (-y) → x + y

Fields

expr_to_idx: FxHashMap<*const SymbolicExpression<F>, usize>

Cache: Arc pointer -> node index (fast path for same Arc)

node_to_idx: FxHashMap<SymbolicExpressionNode<F>, usize>

Cache: node structure -> node index (structural deduplication)

nodes: Vec<SymbolicExpressionNode<F>>

Nodes in topological order

Implementations

impl<F: Field> SymbolicDagBuilder<F>

pub fn new() -> Self

pub fn add_expr(&mut self, expr: &SymbolicExpression<F>) -> usize

Add a symbolic expression to the DAG, returning its node index. Performs structural deduplication and algebraic simplifications.

Trait Implementations

impl<F: Field> Default for SymbolicDagBuilder<F>

fn default() -> Self

Returns the “default value” for a type.