Enum TapeOp 

pub enum TapeOp {
    Const(f64),
    Var(usize),
    Add(usize, usize),
    Sub(usize, usize),
    Mul(usize, usize),
    Div(usize, usize),
    Pow(usize, usize),
    Neg(usize),
    Abs(usize),
    Sqrt(usize),
    Exp(usize),
    Log(usize),
    Log10(usize),
    Sin(usize),
    Cos(usize),
    Tan(usize),
    Atan(usize),
    Acos(usize),
    Sinh(usize),
    Cosh(usize),
    Tanh(usize),
    Asin(usize),
    Acosh(usize),
    Asinh(usize),
    Atanh(usize),
    Atan2(usize, usize),
    Min(usize, usize),
    Max(usize, usize),
    Cmp(CmpOp, usize, usize),
    And(usize, usize),
    Or(usize, usize),
    Not(usize),
    Select(usize, usize, usize),
    Funcall(Box<FuncallData>),
}

One operation in the flattened tape. Operand fields are tape-slot indices into the same tape; Var(i) references problem variable index i (read from the input x slice during forward).

Variants

Const(f64)

Var(usize)

Add(usize, usize)

Sub(usize, usize)

Mul(usize, usize)

Div(usize, usize)

Pow(usize, usize)

Neg(usize)

Abs(usize)

Sqrt(usize)

Exp(usize)

Log(usize)

Log10(usize)

Sin(usize)

Cos(usize)

Tan(usize)

Atan(usize)

Acos(usize)

Sinh(usize)

Cosh(usize)

Tanh(usize)

Asin(usize)

Acosh(usize)

Asinh(usize)

Atanh(usize)

Atan2(usize, usize)

Two-argument arctangent atan2(vals[a], vals[b]) (operands are (y, x), matching AMPL’s atan2(y, x) / .nl opcode o48).

Min(usize, usize)

Pairwise minimum min(vals[a], vals[b]). Piecewise linear: the value/tangent/adjoint route through whichever operand is smaller (ties pick the first), and the second derivative is identically zero. n-ary AMPL min (opcode o11) folds to a chain of these.

Max(usize, usize)

Pairwise maximum max(vals[a], vals[b]) — the Min mirror; n-ary AMPL max (opcode o12) folds to a chain of these.

Cmp(CmpOp, usize, usize)

Relational comparison vals[a] OP vals[b] → 1.0/0.0. Piecewise constant, so its derivative is identically zero — the AD passes treat it as a constant w.r.t. its operands.

And(usize, usize)

Logical AND: 1.0 iff both operands are nonzero. Zero derivative.

Or(usize, usize)

Logical OR: 1.0 iff either operand is nonzero. Zero derivative.

Not(usize)

Logical NOT: 1.0 iff the operand is zero. Zero derivative.

Select(usize, usize, usize)

if-then-else: operands (cond, then, else). The value is vals[then] when vals[cond] != 0 else vals[else], and the value/tangent/adjoint all route through the active branch only. The condition contributes no derivative (the branch switch is a non-smooth event the AD ignores).

Funcall(Box<FuncallData>)

AMPL imported (external) function call. The payload (library handle, name, and argument list) is boxed so this rare variant does not inflate size_of::<TapeOp>(): without the box the Arc+String+Vec make every op ~64 bytes, which on a summand-split objective with millions of tiny tapes (e.g. sensors) costs gigabytes. Boxing drops the common arithmetic ops back to the size of the next-largest variant.

Trait Implementations

impl Clone for TapeOp

fn clone(&self) -> TapeOp

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TapeOp

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

Formats the value using the given formatter.