cqlib_core/circuit/gate/
classical_data.rs

1// This code is part of Cqlib.
2//
3// (C) Copyright China Telecom Quantum Group 2026
4//
5// This code is licensed under the Apache License, Version 2.0. You may
6// obtain a copy of this license in the LICENSE.txt file in the root directory
7// of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
8//
9// Any modifications or derivative works of this code must retain this
10// copyright notice, and modified files need to carry a notice indicating
11// that they have been altered from the originals.
12
13//! Side-effecting runtime classical data instructions.
14//!
15//! These instructions connect quantum measurements and typed classical
16//! storage. Pure computations remain represented by
17//! [`ClassicalExpr`].
18
19use crate::circuit::{ClassicalExpr, ClassicalValue, ClassicalVar};
20use std::fmt;
21
22/// Runtime classical data operation.
23///
24/// These operations are side-effecting classical updates in the circuit
25/// schedule. They produce or overwrite runtime classical storage, while
26/// [`ClassicalExpr`] remains side-effect-free and only reads runtime classical
27/// variables or immutable values.
28#[derive(Debug, Clone, PartialEq)]
29pub enum ClassicalDataOp {
30    /// Stores an expression value into a mutable classical variable.
31    Store {
32        /// Mutable storage location being updated.
33        target: ClassicalVar,
34        /// Type-compatible value expression to store.
35        value: ClassicalExpr,
36    },
37    /// Measures one qubit and produces an immutable `Bit` value.
38    MeasureBit {
39        /// Immutable value receiving the measurement result.
40        result: ClassicalValue,
41    },
42    /// Measures several qubits and produces an immutable `BitVec(width)` value.
43    ///
44    /// The operation qubit order is the bit-vector order, with qubit index 0
45    /// mapped to the least-significant bit.
46    MeasureBits {
47        /// Immutable bit-vector value receiving the packed result.
48        result: ClassicalValue,
49    },
50}
51
52impl ClassicalDataOp {
53    /// Returns the stable snake-case operation name.
54    pub const fn name(&self) -> &'static str {
55        match self {
56            Self::Store { .. } => "store",
57            Self::MeasureBit { .. } => "measure_bit",
58            Self::MeasureBits { .. } => "measure_bits",
59        }
60    }
61
62    /// Returns the mutable store target, if this is a store operation.
63    pub fn target(&self) -> Option<ClassicalVar> {
64        match self {
65            Self::Store { target, .. } => Some(*target),
66            Self::MeasureBit { .. } | Self::MeasureBits { .. } => None,
67        }
68    }
69
70    /// Returns the immutable measurement result, if this is a measurement.
71    pub fn result(&self) -> Option<ClassicalValue> {
72        match self {
73            Self::Store { .. } => None,
74            Self::MeasureBit { result } | Self::MeasureBits { result } => Some(*result),
75        }
76    }
77
78    /// Returns the stored expression, if this is a store operation.
79    pub fn value(&self) -> Option<&ClassicalExpr> {
80        match self {
81            Self::Store { value, .. } => Some(value),
82            Self::MeasureBit { .. } | Self::MeasureBits { .. } => None,
83        }
84    }
85}
86
87impl fmt::Display for ClassicalDataOp {
88    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
89        f.write_str(self.name())
90    }
91}
cqlib_core/circuit/gate/classical_data.rs

cqlib_core/circuit/gate/
classical_data.rs
