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
use crate::quantum::types::{
quantum_gate::QuantumGate, qubit::Qubit, qubit_register::QubitRegister,
};
impl QubitRegister {
/// [`QubitRegister::new`] Creates a new [`QubitRegister`] with a specified number
/// of [`Qubits`](crate::quantum::types::qubit::Qubit), all initialized as [`Qubit::zero`].
///
/// # Example
/// [`QubitRegister::new`] can be used to create a new [`QubitRegister`].
/// ```rust
/// use rquant::quantum::types::{qubit_register::QubitRegister, qubit::Qubit};
///
/// fn create_qubit_register(amount: usize) -> QubitRegister {
/// QubitRegister::new(amount)
/// }
/// ```
pub fn new(num_qubits: usize) -> Self {
QubitRegister {
qubits: (0..num_qubits).map(|_| Qubit::zero()).collect(),
}
}
/// [`QubitRegister::len`] returns the number of qubits in the register.
///
/// # Example
/// [`QubitRegister::len`] can be used to return the number of
/// [`Qubits`](crate::quantum::types::qubit::Qubit) in a [`QubitRegister`]:
/// ```rust
/// use rquant::quantum::types::{qubit_register::QubitRegister, qubit::Qubit};
///
/// fn count_qubits_in_register(qubit_register: QubitRegister) -> usize {
/// qubit_register.len()
/// }
/// ```
pub fn len(&self) -> usize {
self.qubits.len()
}
/// [`QubitRegister::is_empty`] returns `true` if the register has no
/// [`Qubits`](crate::quantum::types::qubit::Qubit), and `false` otherwise.
///
/// # Example
/// [`QubitRegister::is_empty`] can be used to determine if a [`QubitRegister`]
/// has any [`Qubits`](crate::quantum::types::qubit::Qubit):
/// ```rust
/// use rquant::quantum::types::{qubit_register::QubitRegister, qubit::Qubit};
///
/// fn register_has_qubits(qubit_register: QubitRegister) -> bool {
/// !qubit_register.is_empty()
/// }
/// ```
pub fn is_empty(&self) -> bool {
self.qubits.len() == 0
}
/// [`QubitRegister::get`] gets a reference to a specific qubit in the register,
/// and returns [`None`] if the `index` is out of bounds.
///
/// # Example
/// [`QubitRegister::get`] can be used to get a [`Qubit`] from a [`QubitRegister`]:
/// ```rust
/// use rquant::quantum::types::{qubit_register::QubitRegister, qubit::Qubit};
///
/// fn get_second_qubit(qubit_register: &QubitRegister) -> &Qubit {
/// qubit_register.get(1).expect("Register did not have two qubits.")
/// }
/// ```
pub fn get(&self, index: usize) -> Option<&Qubit> {
self.qubits.get(index)
}
/// [`QubitRegister::get_mut`] gets a mutable reference to a specific qubit in
/// the register, and returns [`None`] if the `index` is out of bounds.
///
/// # Example
/// [`QubitRegister::get_mut`] can be used to get a mutable [`Qubit`] from a
/// [`QubitRegister`]:
/// ```rust
/// use rquant::quantum::types::{qubit_register::QubitRegister, qubit::Qubit};
///
/// fn get_second_qubit(qubit_register: &mut QubitRegister) -> &mut Qubit {
/// qubit_register.get_mut(1).expect("Register did not have two qubits.")
/// }
/// ```
pub fn get_mut(&mut self, index: usize) -> Option<&mut Qubit> {
self.qubits.get_mut(index)
}
/// [`QubitRegister::apply_single_qubit_gate`] applies a single-qubit [`QuantumGate`]
/// to a specific [`Qubit`] in a [`QubitRegister`].
///
/// # Example
/// [`QubitRegister::apply_single_qubit_gate`] can be used to apply a single-qubit
/// [`QuantumGate`] to a [`Qubit`] in a [`QubitRegister`]:
/// ```rust
/// use rquant::quantum::types::{
/// quantum_gate::QuantumGate,
/// qubit_register::QubitRegister,
/// qubit::Qubit
/// };
///
/// fn flip_second_qubit_in_register(qubit_register: &mut QubitRegister) {
/// qubit_register.apply_single_qubit_gate(&QuantumGate::NOT, 1)
/// }
/// ```
pub fn apply_single_qubit_gate(&mut self, gate: &QuantumGate, target_qubit: usize) {
if let Some(qubit) = self.qubits.get_mut(target_qubit) {
*qubit = qubit.apply_gate(gate);
} else {
eprintln!("Error: Invalid qubit index");
}
}
}
/// Implement the [`std::fmt::Display`] trait for [`QubitRegister`].
impl std::fmt::Display for QubitRegister {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "<")?;
for (i, qubit) in self.qubits.iter().enumerate() {
write!(f, "{}", qubit)?;
if i < self.qubits.len() - 1 {
write!(f, ", ")?;
}
}
write!(f, ">")
}
}