Merge pull request #14 from notmgsk/3-less-panics

Catch out-of-bounds errors when creating gate matrices
notmgsk · Jul 17, 2021 · af4c703 · af4c703
2 parents 49116d9 + 4ee5cd1
commit af4c703
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Showing 6 changed files with 277 additions and 167 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -22,4 +22,4 @@ thiserror = "1.0.24"
 anyhow = "1.0.39"
 
 [dev-dependencies]
-pretty_assertions = "0.7.2"
+pretty_assertions = "0.7.2"
diff --git a/src/gates/mod.rs b/src/gates/mod.rs
@@ -3,42 +3,20 @@ pub mod standard;
 use ndarray::{Array, Array2};
 use num::complex::Complex64;
 
-use crate::gates::standard::{ccnot, cnot, cz, h, i, rx, ry, rz, swap, x, z};
+use crate::gates::standard::swap;
 
 #[derive(Default, Clone, Debug)]
 pub struct QGate {
     matrix: Array2<Complex64>,
     qubits: Vec<usize>,
 }
 
-pub fn gate_matrix(name: String, params: Vec<f64>, qubits: Vec<usize>) -> QGate {
-    match name.as_str() {
-        "I" => i(qubits[0]),
-        "X" => x(qubits[0]),
-        "Y" => x(qubits[0]),
-        "Z" => z(qubits[0]),
-        "RX" => rx(params[0], qubits[0]),
-        "RY" => ry(params[0], qubits[0]),
-        "RZ" => rz(params[0], qubits[0]),
-        "H" => h(qubits[0]),
-        "CZ" => cz(qubits[0], qubits[1]),
-        "CNOT" => cnot(qubits[0], qubits[1]),
-        "SWAP" => swap(qubits[0], qubits[1]),
-        "CCNOT" => ccnot(qubits[0], qubits[1], qubits[2]),
-        _ => todo!(),
-    }
-}
-
-// TODO Is it possible to define a SquareArray2 type (where dimensions are equal)
-// TODO Likewise, an array type which is both square and each dimension is 2^n
-
 impl QGate {
     fn lift_adjacent(&self, i: usize, n_qubits: usize) -> Array2<Complex64> {
         let gate_size = self.qubits.len();
         let n = num::pow(2, i);
         let bottom = Array::eye(n);
-        let top =
-            Array::eye(2u64.pow((n_qubits as u32) - (i as u32) - (gate_size as u32)) as usize);
+        let top = Array::eye(2u64.pow((n_qubits - i - gate_size) as u32) as usize);
 
         kron(&top, &kron(&self.matrix, &bottom))
     }
@@ -116,11 +94,12 @@ mod tests {
     use ndarray::arr2;
     use pretty_assertions::assert_eq;
 
+    use crate::gates::standard::{cnot, x};
     use crate::matrix::{C0, C1};
 
     #[test]
     fn lift_1q() {
-        let gate = super::x(0);
+        let gate = x(0);
         assert_eq!(
             gate.lift_adjacent(0, 2),
             arr2(&[
@@ -131,7 +110,7 @@ mod tests {
             ])
         );
 
-        let gate = super::x(1);
+        let gate = x(1);
         assert_eq!(
             gate.lift_adjacent(1, 2),
             arr2(&[
@@ -150,7 +129,7 @@ mod tests {
 
     #[test]
     fn lift_2q() {
-        let gate = super::cnot(0, 1);
+        let gate = cnot(0, 1);
         assert_eq!(
             gate.lift(2),
             arr2(&[
@@ -161,7 +140,7 @@ mod tests {
             ])
         );
 
-        let gate = super::cnot(1, 0);
+        let gate = cnot(1, 0);
         assert_eq!(
             gate.lift(2),
             arr2(&[
@@ -172,7 +151,7 @@ mod tests {
             ])
         );
 
-        let gate = super::cnot(0, 2);
+        let gate = cnot(0, 2);
         assert_eq!(
             gate.lift(3),
             arr2(&[
@@ -187,7 +166,7 @@ mod tests {
             ])
         );
 
-        let gate = super::cnot(2, 0);
+        let gate = cnot(2, 0);
         assert_eq!(
             gate.lift(3),
             arr2(&[