From 37d6125afba125f7ef55022b9a81385f2811ddf6 Mon Sep 17 00:00:00 2001
From: AntonReinhard <anton.reinhard@proton.me>
Date: Fri, 5 Jul 2024 14:13:15 +0200
Subject: [PATCH] Add convenience constructors for particle statefuls

---
 src/phase_spaces/create.jl | 19 ++++++++++++++++++-
 test/phase_spaces.jl       |  3 +++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/phase_spaces/create.jl b/src/phase_spaces/create.jl
index 4364e5a..bb1d4d4 100644
--- a/src/phase_spaces/create.jl
+++ b/src/phase_spaces/create.jl
@@ -1,5 +1,22 @@
-# PSP constructors from particle statefuls
+"""
+    ParticleStateful{DIR, SPECIES}(mom::AbstractFourMomentum)
+    ParticleStateful{DIR, SPECIES, EL}(mom::EL)
+
+Construct a [`ParticleStateful`](@ref) from the given momentum on a fully or partially specified type.
+"""
+@inline function ParticleStateful{DIR,SPECIES}(
+    mom::AbstractFourMomentum
+) where {DIR<:ParticleDirection,SPECIES<:AbstractParticleType}
+    return ParticleStateful(DIR(), SPECIES(), mom)
+end
+
+@inline function ParticleStateful{DIR,SPECIES,EL}(
+    mom::EL
+) where {DIR<:ParticleDirection,SPECIES<:AbstractParticleType,EL<:AbstractFourMomentum}
+    return ParticleStateful(DIR(), SPECIES(), mom)
+end
 
+# PSP constructors from particle statefuls
 """
     InPhaseSpacePoint(
         proc::AbstractProcessDefinition, 
diff --git a/test/phase_spaces.jl b/test/phase_spaces.jl
index 6ef7a06..e26a389 100644
--- a/test/phase_spaces.jl
+++ b/test/phase_spaces.jl
@@ -23,6 +23,9 @@ end
         mom = rand(RNG, SFourMomentum)
 
         particle_stateful = ParticleStateful(dir, species, mom)
+        @test particle_stateful == ParticleStateful{typeof(dir),typeof(species)}(mom)
+        @test particle_stateful ==
+            ParticleStateful{typeof(dir),typeof(species),typeof(mom)}(mom)
 
         # particle interface
         @test is_fermion(particle_stateful) == is_fermion(species)