Fix typo in enumerate_cliffords and add tests

Fixes #60

Signed-off-by: Stefan Krastanov <stefan@krastanov.org>

CHANGELOG.md

@@ -1,5 +1,9 @@
 # News
 
+## v0.5.3 - 2022-06-11
+
+- **(fix `#60`)** `enumerate_clifford` was broken due to an earlier refactor in `rowswap!`
+
 ## v0.5.2
 
 - Implement the clipped gauge canonicalization `canonicalize_clip!` and related functions.

Project.toml

@@ -1,7 +1,7 @@
 name = "QuantumClifford"
 uuid = "0525e862-1e90-11e9-3e4d-1b39d7109de1"
 authors = ["Stefan Krastanov <stefan@krastanov.org>"]
-version = "0.5.2"
+version = "0.5.3"
 
 [deps]
 Combinatorics = "861a8166-3701-5b0c-9a16-15d98fcdc6aa"

src/enumeration.jl

@@ -60,7 +60,7 @@ end
  comm(basis, δn+start, i)==0x1 && return i
  end
  # the following hapens only if the input is P"X___..."
- rowswap!(basis, δn+start, 2padded_n+1)
+ rowswap!(basis, δn+start, 2padded_n+1; phases=Val(false))
  _findanticommGS(basis, start, n, padded_n, δn)
 end
 
@@ -104,7 +104,7 @@ function symplecticGS(pauli::PauliOperator; padded_n=nqubits(pauli))
  doneupto = 1
  while doneupto <= n
  i = _findanticommGS(basis, doneupto, n, padded_n, δn)
- rowswap!(basis, padded_n+δn+doneupto, i; phases=false)
+ rowswap!(basis, padded_n+δn+doneupto, i; phases=Val(false))
  _eliminateGS(basis, doneupto, n, padded_n, δn)
  doneupto += 1
  end
@@ -196,4 +196,4 @@ julia> length(collect(enumerate_phases(enumerate_cliffords(2))))
 See also: [`enumerate_cliffords`](@ref), [`clifford_cardinality`](@ref)."""
 function enumerate_phases(ops::Union{AbstractVector,Base.Generator})
  Iterators.flatten(Iterators.map(enumerate_phases, ops))
-end
+end

test/runtests.jl

@@ -46,6 +46,7 @@ doset("bitpack") && include("./test_bitpack.jl")
 doset("graphs") && include("./test_graphs.jl")
 doset("hash") && include("./test_hash.jl")
 doset("entanglement") && include("./test_entanglement.jl")
+doset("enumeration") && include("./test_enumerate.jl")
 doset("doctests") && include("./doctests.jl")
 
 using Aqua

test/test_enumerate.jl

@@ -0,0 +1,11 @@
+function test_enumeration()
+ @testset "Enumeration" begin
+ @test Set([copy(op) for op in enumerate_cliffords(1)]) == Set((random_clifford(1,phases=false) for i in 1:70))
+ @test Set([copy(op) for op in enumerate_phases(enumerate_cliffords(1))]) == Set((random_clifford(1,phases=true) for i in 1:300))
+ @test length(collect(enumerate_cliffords(2))) == length(collect(enumerate_phases(enumerate_cliffords(2))))/2^4 == 720
+ @test first(enumerate_cliffords(3)) == C"X__ __Z _Z_ Z__ __X _X_"
+ @test first(enumerate_cliffords(5)) == C"X____ ____Z ___Z_ __Z__ _Z___ Z____ ____X ___X_ __X__ _X___"
+ end
+end
+
+test_enumeration()