permit ClassicalControl with no quantum gate

Project.toml

@@ -1,7 +1,7 @@
 name = "Quantikz"
 uuid = "b0d11df0-eea3-4d79-b4a5-421488cbf74b"
 authors = ["Stefan Krastanov <[email protected]>"]
-version = "1.3"
+version = "1.3.1"
 
 [deps]
 EndpointRanges = "340492b5-2a47-5f55-813d-aca7ddf97656"

src/Quantikz.jl

@@ -304,17 +304,22 @@ ClassicalDecision(t::Integer, c::Integer) = ClassicalDecision("\\;\\;", [t], [c]
 ClassicalDecision(t::ArrayOrRange, c::Integer) = ClassicalDecision("\\;\\;", t, [c])
 ClassicalDecision(t::Integer, c::ArrayOrRange) = ClassicalDecision("\\;\\;", [t], c)
 ClassicalDecision(t::ArrayOrRange, c::ArrayOrRange) = ClassicalDecision("\\;\\;", t, c)
+ClassicalDecision(c::ArrayOrRange) = ClassicalDecision("", [], c)
 
 affectedqubits(g::ClassicalDecision) = g.targets
 affectedbits(g::ClassicalDecision) = g.bits
 function update_table!(qtable,step,g::ClassicalDecision)
     qvtable = qubitsview(qtable)
     bvtable = bitsview(qtable)
-    m, M = explicit_extrema(qvtable, g.targets)
-    draw_rectangle!(qvtable,step,g.targets,g.str)
     bits = explicit_targets(bvtable, g.bits)
     startpoint = minimum(bits)
-    bvtable[startpoint,step] = "\\cwbend{$(-(qtable.qubits-M)-qtable.ancillaries-startpoint)}"
+    if !isa(g.targets,AbstractVector) || length(g.targets)>0
+        m, M = explicit_extrema(qvtable, g.targets)
+        draw_rectangle!(qvtable,step,g.targets,g.str)
+        bvtable[startpoint,step] = "\\cwbend{$(-(qtable.qubits-M)-qtable.ancillaries-startpoint)}"
+    else
+        bvtable[startpoint,step] = "\\cwbend{0}"
+    end
     for b in sort(bits)[2:end]
         bvtable[b,step] = "\\cwbend{$(startpoint-b)}"
         startpoint = b
@@ -410,7 +415,11 @@ function circuit2table_compressed(circuit, qubits)
     for op in circuit
         qubits = extrema2range(explicit_extrema(qvtable, affectedqubits(op)))
         if circuitwidthbits(op)!=0 || neededancillaries(op)!=0
-            qubits = minimum(qubits):iend
+            qubits = if length(qubits)==0
+                ibegin:iend # TODO this branch is too pessimistic
+            else
+                minimum(qubits):iend
+            end
         end
         bits = extrema2range(explicit_extrema(bvtable, affectedbits(op)))
         ancillaries = neededancillaries(op)

test/runtests.jl

@@ -108,10 +108,19 @@ end
 @testset "EndpointRanges in ClassicalDecision" begin
 circuit = [U(5),ClassicalDecision(ibegin:iend,2),ClassicalDecision(1,ibegin:iend)]
 @test circuit2string(circuit) == circuit2string(circuit,mode=:expanded) == "\\begin{quantikz}[transparent, row sep={0.8cm,between origins}]\n\\qw & \\qw & \\gate[5,disable auto height]{\\;\\;} & \\gate[1]{\\;\\;} & \\qw\\\\\n\\qw & \\qw & \\qw & \\qw & \\qw\\\\\n\\qw & \\qw & \\qw & \\qw & \\qw\\\\\n\\qw & \\qw & \\qw & \\qw & \\qw\\\\\n\\qw & \\gate{\\;\\;} & \\qw & \\qw & \\qw\\\\\n\\cw & \\cw & \\cw & \\cwbend{-5} & \\cw\\\\\n\\cw & \\cw & \\cwbend{-2} & \\cwbend{-1} & \\cw\n\\end{quantikz}"
+circuit2string(circuit,mode=:compressed)
 circuit = [ClassicalDecision(ibegin:iend,ibegin:iend)]
 @test circuit2string(circuit) == circuit2string(circuit,mode=:expanded) == "\\begin{quantikz}[transparent, row sep={0.8cm,between origins}]\n\\qw & \\gate[1]{\\;\\;} & \\qw\\\\\n\\cw & \\cwbend{-1} & \\cw\n\\end{quantikz}"
+circuit2string(circuit,mode=:compressed)
 end
 
+@testset "no quantum component in ClassicalDecision" begin
+circuit = [U(5),ClassicalDecision([2]),ClassicalDecision(ibegin:iend)]
+@test circuit2string(circuit) == circuit2string(circuit,mode=:expanded)
+circuit2string(circuit,mode=:compressed)
+end
+
+
 @testset "Consecutive gates should not confuse the `deleted` count in `draw_rectangle`" begin
 circuit = [MultiControlU("XYZ",  [1], [2], [3,4,5]), MultiControlU("U_a",  [1], [2], [3,5])]
 @test circuit2string(circuit) == circuit2string(circuit,mode=:expanded) == "\\begin{quantikz}[transparent, row sep={0.8cm,between origins}]\n\\qw & \\ctrl{0} & \\ctrl{0} & \\qw\\\\\n\\qw & \\octrl{-1} & \\octrl{-1} & \\qw\\\\\n\\qw & \\gate[3,disable auto height]{XYZ}\\vqw{-1} & \\gate[3,label style={yshift=0.2cm},disable auto height]{U_a}\\vqw{-1} & \\qw\\\\\n\\qw & \\qw & \\linethrough & \\qw\\\\\n\\qw & \\qw & \\qw & \\qw\n\\end{quantikz}"