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81b9e0e | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 | //! # utqc-core
//!
//! Circuit IR — Gate, Qubit, Circuit, Measurement.
//! Non-recursive. Every circuit compiles to a flat list of operations.
use serde::{Deserialize, Serialize};
use thiserror::Error;
/// Errors in circuit construction or execution.
#[derive(Error, Debug, Clone, PartialEq, Eq)]
pub enum CircuitError {
/// Qubit index out of bounds.
#[error("qubit index {0} out of bounds (circuit has {1} qubits)")]
QubitOutOfBounds(usize, usize),
/// Duplicate measurement on the same qubit.
#[error("duplicate measurement on qubit {0}")]
DuplicateMeasurement(usize),
/// Empty circuit.
#[error("circuit is empty")]
EmptyCircuit,
}
/// A single qubit identifier.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub struct Qubit(pub usize);
/// Single-qubit gate types.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub enum SingleGate {
/// Pauli-X (NOT).
PauliX,
/// Pauli-Y.
PauliY,
/// Pauli-Z.
PauliZ,
/// Hadamard.
Hadamard,
/// T-gate (π/8 phase).
TGate,
/// S-gate (π/4 phase).
SGate,
}
/// Two-qubit gate types.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub enum DoubleGate {
/// Controlled-NOT.
CNOT,
/// Controlled-Z.
CZ,
/// SWAP.
SWAP,
}
/// A gate operation in the circuit.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub enum Gate {
/// Single-qubit gate.
Single {
/// Gate type.
gate: SingleGate,
/// Target qubit.
target: Qubit,
},
/// Two-qubit gate.
Double {
/// Gate type.
gate: DoubleGate,
/// Control qubit.
control: Qubit,
/// Target qubit.
target: Qubit,
},
/// Rotation gate (parameterized).
Rotation {
/// Target qubit.
target: Qubit,
/// Angle in radians.
angle: f64,
},
}
/// A measurement record.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub struct Measurement {
/// Qubit being measured.
pub qubit: Qubit,
/// Classical bit index to store result.
pub classical_bit: usize,
}
/// A quantum circuit — non-recursive flat IR.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct Circuit {
/// Number of qubits in the circuit.
pub num_qubits: usize,
/// Number of classical bits.
pub num_classical_bits: usize,
/// Ordered list of gate operations.
pub gates: Vec<Gate>,
/// Measurements to perform at the end.
pub measurements: Vec<Measurement>,
}
impl Circuit {
/// Create a new empty circuit.
pub fn new(num_qubits: usize, num_classical_bits: usize) -> Self {
Self {
num_qubits,
num_classical_bits,
gates: Vec::new(),
measurements: Vec::new(),
}
}
/// Add a gate to the circuit.
pub fn add_gate(&mut self, gate: Gate) -> Result<(), CircuitError> {
match &gate {
Gate::Single { target, .. } => {
if target.0 >= self.num_qubits {
return Err(CircuitError::QubitOutOfBounds(target.0, self.num_qubits));
}
}
Gate::Double { control, target, .. } => {
if control.0 >= self.num_qubits {
return Err(CircuitError::QubitOutOfBounds(control.0, self.num_qubits));
}
if target.0 >= self.num_qubits {
return Err(CircuitError::QubitOutOfBounds(target.0, self.num_qubits));
}
}
Gate::Rotation { target, .. } => {
if target.0 >= self.num_qubits {
return Err(CircuitError::QubitOutOfBounds(target.0, self.num_qubits));
}
}
}
self.gates.push(gate);
Ok(())
}
/// Add a measurement.
pub fn add_measurement(&mut self, qubit: Qubit, classical_bit: usize) -> Result<(), CircuitError> {
if qubit.0 >= self.num_qubits {
return Err(CircuitError::QubitOutOfBounds(qubit.0, self.num_qubits));
}
if self.measurements.iter().any(|m| m.qubit == qubit) {
return Err(CircuitError::DuplicateMeasurement(qubit.0));
}
self.measurements.push(Measurement { qubit, classical_bit });
Ok(())
}
/// Number of gates in the circuit.
pub fn depth(&self) -> usize {
self.gates.len()
}
/// Validate the circuit.
pub fn validate(&self) -> Result<(), CircuitError> {
if self.gates.is_empty() && self.measurements.is_empty() {
return Err(CircuitError::EmptyCircuit);
}
Ok(())
}
}
/// The non-recursive pass trait.
pub trait Pass {
/// Input type for this pass.
type Input;
/// Output type for this pass.
type Output;
/// Name of this pass.
fn name(&self) -> &'static str;
/// Execute the pass.
fn run(&self, input: Self::Input) -> Result<Self::Output, CircuitError>;
}
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