adding doctests and some basic tests

src/nonclifford.jl

@@ -64,7 +64,6 @@ DataStructures.DefaultDict{Tuple{BitVector, BitVector}, ComplexF64, ComplexF64}
   ([1], [0]) => 0.0-0.353553im
   ([0], [0]) => 0.853553+0.0im
   ([1], [1]) => 0.146447+0.0im
-
 ```
 
 See also: [`PauliChannel`](@ref)
@@ -157,8 +156,8 @@ function (⊗)(state₁::GeneralizedStabilizer, state₂::GeneralizedStabilizer)
         end
     end
     newsm.destabweights = newdict
-    newsm
-end 
+    return newsm
+end
 
 """
 $(TYPEDSIGNATURES)
@@ -189,13 +188,50 @@ function (*)(Op::AbstractCliffordOperator, state::GeneralizedStabilizer)
     dtype = valtype(dict)
     tzero = zero(dtype)
     newdict = typeof(dict)(tzero)
-    newstab = Op * state.stab 
+    newstab = Op * state.stab
+    n = nqubits(newstab)
+    newsm = GeneralizedStabilizer(newstab, DefaultDict(0.0im, (falses(n),falses(n))=>1.0+0.0im))
+    newsm.destabweights = dict
+    return newsm
+end
+
+"""
+$(TYPEDSIGNATURES)
+
+```jldoctest
+julia> sm = GeneralizedStabilizer(S"-X")
+A mixture ∑ ϕᵢⱼ Pᵢ ρ Pⱼ† where ρ is
+𝒟ℯ𝓈𝓉𝒶𝒷
++ Z
+𝒮𝓉𝒶𝒷
+- X
+with ϕᵢⱼ | Pᵢ | Pⱼ:
+ 1.0+0.0im | + _ | + _
+
+julia> P"-Y" * sm
+A mixture ∑ ϕᵢⱼ Pᵢ ρ Pⱼ† where ρ is
+𝒟ℯ𝓈𝓉𝒶𝒷
+- Z
+𝒮𝓉𝒶𝒷
++ X
+with ϕᵢⱼ | Pᵢ | Pⱼ:
+ 1.0+0.0im | + _ | + _
+```
+
+"""
+function (*)(Op::PauliOperator, state::GeneralizedStabilizer)
+    dict = state.destabweights
+    dtype = valtype(dict)
+    tzero = zero(dtype)
+    newdict = typeof(dict)(tzero)
+    newstab = Op * state.stab
     n = nqubits(newstab)
     newsm = GeneralizedStabilizer(newstab, DefaultDict(0.0im, (falses(n),falses(n))=>1.0+0.0im))
     newsm.destabweights = dict
-    newsm
+    return newsm
 end 
 
+
 """$(TYPEDSIGNATURES)
 
 Expectation value for the [PauliOperator](@ref) observable given the [`GeneralizedStabilizer`](@ref) state `s`."""
@@ -410,15 +446,6 @@ nqubits(pc::UnitaryPauliChannel) = nqubits(pc.paulis[1])
 
 apply!(state::GeneralizedStabilizer, gate::UnitaryPauliChannel; prune_threshold::Union{Nothing, Float64}=nothing) = prune_threshold === nothing ? apply!(state, gate.paulichannel) : apply!(state, gate.paulichannel, prune_threshold)
 
-##
-# Predefined Pauli Channels
-##
-
-const pcT = UnitaryPauliChannel(
-    (I, Z),
-    ((1+exp(im*π/4))/2, (1-exp(im*π/4))/2)
-)
-
 """
 $(TYPEDSIGNATURES)
 
@@ -443,7 +470,7 @@ function (⊗)(gate::AbstractPauliChannel, Op::PauliOperator)
     new_paulis = (p₁, p₂)
     weights = gate.weights
     return UnitaryPauliChannel(new_paulis, weights)
-end 
+end
 
 """
 $(TYPEDSIGNATURES)
@@ -473,7 +500,6 @@ function (*)(Op::AbstractCliffordOperator, gate::AbstractPauliChannel)
     return UnitaryPauliChannel(new_paulis, weights)
 end
 
-
 """
 $(TYPEDSIGNATURES)
 
@@ -495,7 +521,20 @@ A mixture ∑ ϕᵢⱼ Pᵢ ρ Pⱼ† where ρ is
 - X
 with ϕᵢⱼ | Pᵢ | Pⱼ:
  1.0+0.0im | + _ | + _
+
+julia> sm == copy(sm)
+true
 ```
 
 """
 Base.copy(sm::GeneralizedStabilizer) = GeneralizedStabilizer(copy(sm.stab),copy(sm.destabweights))
+Base.:(==)(sm₁::GeneralizedStabilizer, sm₂::GeneralizedStabilizer) = sm₁.stab==sm₂.stab && sm₁.destabweights==sm₂.destabweights
+
+##
+# Predefined Pauli Channels
+##
+
+const pcT = UnitaryPauliChannel(
+    (I, Z),
+    ((1+exp(im*π/4))/2, (1-exp(im*π/4))/2)
+)

test/test_paulis.jl

@@ -1,6 +1,6 @@
 @testitem "Pauli Operators" begin
-  using QuantumClifford: apply_single_x!, apply_single_y!, apply_single_z!
-  test_sizes = [1,2,10,63,64,65,127,128,129] # Including sizes that would test off-by-one errors in the bit encoding.
+    using QuantumClifford: apply_single_x!, apply_single_y!, apply_single_z!
+    test_sizes = [1,2,10,63,64,65,127,128,129] # Including sizes that would test off-by-one errors in the bit encoding.
 
     @testset "Parsing, constructors, and properties" begin
         @test P"-iXYZ" == PauliOperator(0x3, 3, vcat(BitArray([1,1,0]).chunks, BitArray([0,1,1]).chunks))
@@ -90,5 +90,31 @@
                 end
             end
         end
+
+    @testset "Single qubit Paulis and their action on GeneralizedStabilizer" begin
+        for i in 1:3
+            for n in test_sizes
+                x, y, z = rand(1:n), rand(1:n), rand(1:n)
+                px = single_x(n,x)
+                py = single_y(n,y)
+                pz = single_z(n,z)
+                rstab = random_stabilizer(n)
+                s1 = GeneralizedStabilizer(rstab)
+                s2 = copy(s1)
+                s3 = copy(s1)
+                apply!(s1,px)
+                apply_single_x!(s2.stab,x)
+                apply!(s3.stab,P"X",[x])
+                @test s1==s2==s3
+                apply!(s1,py)
+                apply_single_y!(s2.stab,y)
+                apply!(s3.stab,P"Y",[y])
+                @test s1==s2==s3
+                apply!(s1,pz)
+                apply_single_z!(s2.stab,z)
+                apply!(s3.stab,P"Z",[z])
+                @test s1==s2==s3
+            end
+        end
     end
 end

test/test_stabs.jl

@@ -58,6 +58,21 @@
         end
     end
 
+    @testset "Tensor products over generalized stabilizers" begin
+        for n in rand(1:10, 10)
+            l = random_stabilizer(n)
+            r = random_stabilizer(n)
+            sm = GeneralizedStabilizer(l)
+            sm1 = GeneralizedStabilizer(r)
+            s = l⊗r
+            sm2 = sm⊗sm1
+            @test mixed_destab_looks_good(sm2.stab)
+            canonicalize!(s)
+            dss = canonicalize!(copy(stabilizerview(sm2.stab)))
+            @test s == dss
+        end
+    end
+
     @testset "Stabilizer indexing" begin
         s = random_stabilizer(9,10)
         @test s[1,1] == s[[1,3,4],[1,3,5]][1,1]