From 4b053115cb7a0e7f85c057717d19af8126729252 Mon Sep 17 00:00:00 2001
From: Akira Kyle <akira@akirakyle.com>
Date: Thu, 5 Dec 2024 18:14:56 -0700
Subject: [PATCH] Deprecate `PauliBasis` and `equal_bases`

---
 CHANGELOG.md            |  4 ++++
 Project.toml            |  2 +-
 src/QuantumInterface.jl |  1 +
 src/bases.jl            | 29 +++++------------------------
 src/deprecated.jl       | 14 ++++++++++++++
 test/test_bases.jl      |  4 ++--
 6 files changed, 27 insertions(+), 27 deletions(-)
 create mode 100644 src/deprecated.jl

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4c30de4..f086a09 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # News
 
+## v0.3.7 - 2024-12-05
+
+- Rename `PauliBasis` to `NQubitBasis` with warning, and add deprecation to `equal_bases`.
+
 ## v0.3.6 - 2024-09-08
 
 - Add `coherentstate`, `thermalstate`, `displace`, `squeeze`, `wigner`, previously from QuantumOptics.
diff --git a/Project.toml b/Project.toml
index d8b70c0..a02a99b 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "QuantumInterface"
 uuid = "5717a53b-5d69-4fa3-b976-0bf2f97ca1e5"
 authors = ["QuantumInterface.jl contributors"]
-version = "0.3.6"
+version = "0.3.7"
 
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
diff --git a/src/QuantumInterface.jl b/src/QuantumInterface.jl
index 89d3c9a..c1bc651 100644
--- a/src/QuantumInterface.jl
+++ b/src/QuantumInterface.jl
@@ -126,5 +126,6 @@ include("julia_linalg.jl")
 include("sparse.jl")
 
 include("sortedindices.jl")
+include("deprecated.jl")
 
 end # module
diff --git a/src/bases.jl b/src/bases.jl
index 2c059e0..532ad65 100644
--- a/src/bases.jl
+++ b/src/bases.jl
@@ -65,23 +65,6 @@ function equal_shape(a, b)
     return true
 end
 
-"""
-    equal_bases(a, b)
-
-Check if two subbases vectors are identical.
-"""
-function equal_bases(a, b)
-    if a===b
-        return true
-    end
-    for i=1:length(a)
-        if a[i]!=b[i]
-            return false
-        end
-    end
-    return true
-end
-
 ##
 # Common bases
 ##
@@ -126,25 +109,23 @@ end
 
 Base.:(==)(b1::NLevelBasis, b2::NLevelBasis) = b1.N == b2.N
 
-
 """
-    PauliBasis(num_qubits::Int)
+    NQubitBasis(num_qubits::Int)
 
 Basis for an N-qubit space where `num_qubits` specifies the number of qubits.
-The dimension of the basis is 2²ᴺ.
+The dimension of the basis is 2ᴺ.
 """
-struct PauliBasis{S,B} <: Basis
+struct NQubitBasis{S,B} <: Basis
     shape::S
     bases::B
-    function PauliBasis(num_qubits::T) where {T<:Integer}
+    function NQubitBasis(num_qubits::T) where {T<:Integer}
         shape = [2 for _ in 1:num_qubits]
         bases = Tuple(SpinBasis(1//2) for _ in 1:num_qubits)
         return new{typeof(shape),typeof(bases)}(shape, bases)
     end
 end
 
-Base.:(==)(pb1::PauliBasis, pb2::PauliBasis) = length(pb1.bases) == length(pb2.bases)
-
+Base.:(==)(pb1::NQubitBasis, pb2::NQubitBasis) = length(pb1.bases) == length(pb2.bases)
 
 """
     SpinBasis(n)
diff --git a/src/deprecated.jl b/src/deprecated.jl
new file mode 100644
index 0000000..d4aadd5
--- /dev/null
+++ b/src/deprecated.jl
@@ -0,0 +1,14 @@
+function equal_bases(a, b)
+    Base.depwarn("`==` should be preferred over `equal_bases`!", :equal_bases)
+    if a===b
+        return true
+    end
+    for i=1:length(a)
+        if a[i]!=b[i]
+            return false
+        end
+    end
+    return true
+end
+
+Base.@deprecate PauliBasis(num_qubits) NQubitBasis(num_qubits) false
diff --git a/test/test_bases.jl b/test/test_bases.jl
index 1d91673..f6a98c9 100644
--- a/test/test_bases.jl
+++ b/test/test_bases.jl
@@ -1,5 +1,5 @@
 using Test
-using QuantumInterface: tensor, ⊗, ptrace, reduced, permutesystems, equal_bases, multiplicable
+using QuantumInterface: tensor, ⊗, ptrace, reduced, permutesystems, multiplicable
 using QuantumInterface: GenericBasis, CompositeBasis, NLevelBasis, FockBasis
 
 @testset "basis" begin
@@ -49,7 +49,7 @@ comp1 = tensor(b1, b2, b3)
 comp2 = tensor(b2, b1, b3)
 @test permutesystems(comp1, [2,1,3]) == comp2
 
-@test !equal_bases([b1, b2], [b1, b3])
+@test [b1, b2] !== [b1, b3]
 @test !multiplicable(comp1, b1 ⊗ b2 ⊗ NLevelBasis(prod(b3.shape)))
 
 end # testset