Struct Parameters 

pub struct Parameters { /* private fields */ }

Parameter slots over the rotation angles of a circuit.

A slot may drive several instructions (weight sharing): bind writes one angle to each, and the adjoint gradient accumulates their contributions into one entry. Arity is declared at construction rather than inferred from the links, so a value vector of the wrong length is rejected even when the trailing slots carry no link.

Bindable gates are Rx, Ry, Rz, Rzz, P, and PauliRot, the Gate variants carrying a rotation angle.

Implementations

impl Parameters

pub fn new(num_slots: usize) -> Self

Declare num_slots slots with no links yet.

pub fn from_links(links: Vec<ParamLink>, num_slots: usize) -> Self

Build from explicit links over a vector of num_slots entries.

pub fn with_names<I, S>(self, names: I) -> Self

where I: IntoIterator<Item = S>, S: Into<String>,

Name the slots, in slot order. Names are what OpenQASM input declarations carry and what export emits.

Panics

Panics if names is not exactly num_slots long.

pub fn name_of(&self, slot: usize) -> Option<&str>

Name of slot, or None when the set is positional only.

pub fn slot_of(&self, name: &str) -> Option<usize>

Slot a name refers to.

pub fn pinned_to(self, circuit: &Circuit) -> Self

Record the gate kind and targets each link points at, so a later validate against an edited circuit fails loudly rather than binding the wrong gates.

pub fn all_rotations(circuit: &Circuit) -> Self

Give every bindable gate its own slot, in circuit order. The common case for a variational ansatz where each rotation is independent.

pub fn link(&mut self, instruction: usize, slot: usize)

Record that instruction reads slot.

Panics

Panics if slot is not below the declared slot count. Slot bounds are fixed when the set is constructed, so an out-of-range slot is a caller bug rather than bad input.

pub fn links(&self) -> &[ParamLink]

pub fn num_slots(&self) -> usize

Length of the value vector bind expects.

pub fn is_empty(&self) -> bool

True when no instruction is linked. A set may still declare slots.

pub fn validate(&self, circuit: &Circuit) -> Result<()>

Check every link against circuit without binding.

A declared slot that no instruction reads is accepted: OpenQASM allows an input the body never uses, and a sweep may range over a superset of the circuit’s parameters. Use unread_slots to report them.

Errors

Returns PrismError::InvalidParameter when a link points past the end of the instruction stream, at a non-gate instruction, or at a gate carrying no angle.

pub fn unread_slots(&self) -> Vec<usize>

Declared slots that no instruction reads, whose bound values are discarded. Legal, but usually a mistake worth surfacing.

pub fn bind(&self, template: &Circuit, values: &[f64]) -> Result<Circuit>

Write values into a copy of template.

Errors

Returns PrismError::InvalidParameter when values.len() differs from num_slots, when any value is not finite, or when validate rejects the links.

pub fn bind_into( &self, template: &Circuit, values: &[f64], out: &mut Circuit, ) -> Result<()>

Bind into an existing circuit, reusing its allocations.

out is overwritten with template and then patched, so a sweep can hold one buffer across every point instead of allocating per binding.

Errors

Same conditions as bind.

pub fn values(&self, circuit: &Circuit) -> Result<Vec<f64>>

Read the angle each slot currently holds in circuit.

Errors

Same conditions as validate, which this runs first because a link pointing at a non-angle gate has no value to read.

Trait Implementations

impl Clone for Parameters

fn clone(&self) -> Parameters

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Parameters

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

Formats the value using the given formatter.

impl Default for Parameters

fn default() -> Parameters

Returns the “default value” for a type.

impl Eq for Parameters

impl PartialEq for Parameters

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Parameters