ZToXRule

Author: ChenZhao44

src/ZX/ZX.jl

@@ -66,7 +66,7 @@ include("implementations/zx_circuit/phase_tracking.jl")
 # Rules and algorithms
 export AbstractRule
 export Rule, Match
-export FusionRule, XToZRule, Identity1Rule, HBoxRule,
+export FusionRule, XToZRule, ZToXRule, Identity1Rule, HBoxRule,
        PiRule, CopyRule, BialgebraRule,
        LocalCompRule, Pivot1Rule, Pivot2Rule, Pivot3Rule,
        PivotBoundaryRule, PivotGadgetRule,

src/ZX/interfaces/calculus_interface.jl

@@ -59,6 +59,14 @@ phase(circ::AbstractZXCircuit, v) = phase(base_zx_graph(circ), v)
 
 # Spider manipulation
 
+"""
+    $(TYPEDSIGNATURES)
+
+Set the spider type of vertex `v` to `st` in the ZX-diagram.
+"""
+set_spider_type!(::AbstractZXDiagram, v, st) = error("set_spider_type! not implemented")
+set_spider_type!(circ::AbstractZXCircuit, v, st) = set_spider_type!(base_zx_graph(circ), v, st)
+
 """
     $(TYPEDSIGNATURES)
 

src/ZX/rules/color.jl

@@ -1,22 +1,29 @@
 struct XToZRule <: AbstractRule end
+struct ZToXRule <: AbstractRule end
 
-function Base.match(::XToZRule, zxd::ZXDiagram{T, P}) where {T, P}
+Base.match(::XToZRule, zxd::ZXDiagram{T, P}) where {T, P} = match_spider_type(zxd, SpiderType.X)
+Base.match(::XToZRule, zxd::ZXGraph{T, P}) where {T, P} = match_spider_type(zxd, SpiderType.X)
+Base.match(::ZToXRule, zxd::ZXDiagram{T, P}) where {T, P} = match_spider_type(zxd, SpiderType.Z)
+Base.match(::ZToXRule, zxd::ZXGraph{T, P}) where {T, P} = match_spider_type(zxd, SpiderType.Z)
+function match_spider_type(zxd::AbstractZXDiagram{T, P}, st::SpiderType.SType) where {T, P}
     matches = Match{T}[]
     for v1 in spiders(zxd)
-        if spider_type(zxd, v1) == SpiderType.X
+        if spider_type(zxd, v1) == st
             push!(matches, Match{T}([v1]))
         end
     end
     return matches
 end
 
-function check_rule(::XToZRule, zxd::ZXDiagram{T, P}, vs::Vector{T}) where {T, P}
+check_rule(::XToZRule, zxd::ZXDiagram{T, P}, vs::Vector{T}) where {T, P} = check_spider_type(zxd, vs, SpiderType.X)
+check_rule(::XToZRule, zxg::ZXGraph{T, P}, vs::Vector{T}) where {T, P} = check_spider_type(zxg, vs, SpiderType.X)
+check_rule(::ZToXRule, zxd::ZXDiagram{T, P}, vs::Vector{T}) where {T, P} = check_spider_type(zxd, vs, SpiderType.Z)
+check_rule(::ZToXRule, zxg::ZXGraph{T, P}, vs::Vector{T}) where {T, P} = check_spider_type(zxg, vs, SpiderType.Z)
+
+function check_spider_type(zxd::AbstractZXDiagram{T, P}, vs::Vector{T}, st::SpiderType.SType) where {T, P}
     @inbounds v1 = vs[1]
     has_vertex(zxd.mg, v1) || return false
-    if spider_type(zxd, v1) == SpiderType.X
-        return true
-    end
-    return false
+    return spider_type(zxd, v1) == st
 end
 
 function rewrite!(::XToZRule, zxd::ZXDiagram{T, P}, vs::Vector{T}) where {T, P}
@@ -30,32 +37,14 @@ function rewrite!(::XToZRule, zxd::ZXDiagram{T, P}, vs::Vector{T}) where {T, P}
     return zxd
 end
 
-function Base.match(::XToZRule, zxg::ZXGraph{T, P}) where {T, P}
-    matches = Match{T}[]
-    for v1 in spiders(zxg)
-        if spider_type(zxg, v1) == SpiderType.X
-            push!(matches, Match{T}([v1]))
-        end
-    end
-    return matches
-end
-
-function check_rule(::XToZRule, zxg::ZXGraph{T, P}, vs::Vector{T}) where {T, P}
-    @inbounds v1 = vs[1]
-    has_vertex(zxg.mg, v1) || return false
-    if spider_type(zxg, v1) == SpiderType.X
-        return true
-    end
-    return false
-end
-
-function rewrite!(::XToZRule, zxg::ZXGraph{T, P}, vs::Vector{T}) where {T, P}
+function rewrite!(::Union{XToZRule, ZToXRule}, zxg::ZXGraph{T, P}, vs::Vector{T}) where {T, P}
     @inbounds v1 = vs[1]
-    set_spider_type!(zxg, v1, SpiderType.Z)
+    st = spider_type(zxg, v1) == SpiderType.X ? SpiderType.Z : SpiderType.X
+    set_spider_type!(zxg, v1, st)
     for v2 in neighbors(zxg, v1)
         if v2 != v1
-            et = edge_type(zxg, v1, v2)
-            set_edge_type!(zxg, v1, v2, et === EdgeType.SIM ? EdgeType.HAD : EdgeType.SIM)
+            et = edge_type(zxg, v1, v2) === EdgeType.SIM ? EdgeType.HAD : EdgeType.SIM
+            set_edge_type!(zxg, v1, v2, et)
         end
     end
     return zxg