Add some todos, add issame and caninteract to module instead of test

src/models/qed/compute.jl

@@ -32,7 +32,9 @@ function compute(
     data2::QEDParticleValue{P2},
 )::QEDParticleValue where {P1 <: QEDParticle, P2 <: QEDParticle}
     p3 = QED_preserve_momentum(data1.p, data2.p)
-    dataOut = QEDParticleValue{typeof(p3)}(p3, data1.v * ABC_vertex() * data2.v)
+    P3 = interaction_result(P1, P2)
+    # TODO: which of data1 and data2 is left and right might depend on their types?
+    dataOut = QEDParticleValue{P3}(P3(p3), data1.v * ABC_vertex() * data2.v)
     return dataOut
 end
 
@@ -47,9 +49,11 @@ For valid inputs, both input particles should have the same momenta at this poin
 """
 function compute(
     ::ComputeTaskQED_S2,
-    data1::ParticleValue{P},
-    data2::ParticleValue{P},
-)::ComplexF64 where {P <: QEDParticle}
+    data1::ParticleValue{P1},
+    data2::ParticleValue{P2},
+)::ComplexF64 where {P1 <: QEDParticle, P2 <: QEDParticle}
+    @assert issame(P1, propagation_result(P2))
+    # TODO: assert that data1 and data2
     inner = QED_inner_edge(data1.p)
     return data1.v * inner * data2.v
 end

src/models/qed/particle.jl

@@ -177,6 +177,44 @@ end
 @inline direction(::FermionStateful{Dir}) where {Dir <: ParticleDirection} = Dir()
 @inline direction(::AntiFermionStateful{Dir}) where {Dir <: ParticleDirection} = Dir()
 
+"""
+    caninteract(T1::Type{<:QEDParticle}, T2::Type{<:QEDParticle})
+
+For two given [`QEDParticle`](@ref) types, return whether they can interact at a vertex. This is equivalent to `!issame(T1, T2)`.
+
+See also: [`issame`](@ref) and [`interaction_result`](@ref)
+"""
+function caninteract(T1::Type{<:QEDParticle}, T2::Type{<:QEDParticle})
+    if (T1 == T2)
+        return false
+    end
+    if (T1 <: PhotonStateful && T2 <: PhotonStateful)
+        return false
+    end
+
+    for (P1, P2) in [(T1, T2), (T2, T1)]
+        if (P1 == FermionStateful{Incoming} && P2 == AntiFermionStateful{Outgoing})
+            return false
+        end
+        if (P1 == FermionStateful{Outgoing} && P2 == AntiFermionStateful{Incoming})
+            return false
+        end
+    end
+
+    return true
+end
+
+"""
+    issame(T1::Type{<:QEDParticle}, T2::Type{<:QEDParticle})
+
+For two given [`QEDParticle`](@ref) types, return whether they are equivalent for the purpose of a Feynman Diagram. That means e.g. an `Incoming` `AntiFermion` is the same as an `Outgoing` `Fermion`. This is equivalent to `!caninteract(T1, T2)`.
+
+See also: [`caninteract`](@ref) and [`interaction_result`](@ref)
+"""
+function issame(T1::Type{<:QEDParticle}, T2::Type{<:QEDParticle})
+    return !caninteract(T1, T2)
+end
+
 """
     QED_vertex()
 
@@ -192,7 +230,8 @@ end
 Calculate and return a new particle from two given interacting ones at a vertex.
 """
 function QED_preserve_momentum(p1::QEDParticle, p2::QEDParticle)
-    t3 = interaction_result(typeof(p1), typeof(p2))
-    p3 = t3(p1.momentum + p2.momentum)
+    T3 = interaction_result(typeof(p1), typeof(p2))
+    # TODO: probably also need to do something about the spin/pol
+    p3 = T3(p1.momentum + p2.momentum)
     return p3
 end

test/unit_tests_qedmodel.jl

@@ -1,6 +1,8 @@
 using MetagraphOptimization
 using QEDbase
 
+import MetagraphOptimization.caninteract
+import MetagraphOptimization.issame
 import MetagraphOptimization.interaction_result
 import MetagraphOptimization.propagation_result
 import MetagraphOptimization.direction
@@ -25,30 +27,6 @@ testparticleTypesPropagated = [
     AntiFermionStateful{Incoming},
 ]
 
-function caninteract(t1::Type{<:QEDParticle}, t2::Type{<:QEDParticle})
-    if (t1 == t2)
-        return false
-    end
-    if (t1 <: PhotonStateful && t2 <: PhotonStateful)
-        return false
-    end
-
-    for (p1, p2) in [(t1, t2), (t2, t1)]
-        if (p1 == FermionStateful{Incoming} && p2 == AntiFermionStateful{Outgoing})
-            return false
-        end
-        if (p1 == FermionStateful{Outgoing} && p2 == AntiFermionStateful{Incoming})
-            return false
-        end
-    end
-
-    return true
-end
-
-function issame(t1::Type{<:QEDParticle}, t2::Type{<:QEDParticle})
-    return !caninteract(t1, t2)
-end
-
 @testset "Interaction Result" begin
     for p1 in testparticleTypes, p2 in testparticleTypes
         if !caninteract(p1, p2)