From 2df89bc22d0e2286dc96f0a4fa067cb42fb0fd24 Mon Sep 17 00:00:00 2001
From: lkdvos <lukas.devos@ugent.be>
Date: Thu, 21 Dec 2023 12:49:14 +0100
Subject: [PATCH] small changes and comment resolutions

---
 src/operators/multipliedoperator.jl | 29 +++++++++++++----------------
 src/operators/timedependence.jl     |  5 +++--
 test/algorithms.jl                  |  4 ++--
 test/operators.jl                   |  2 +-
 4 files changed, 19 insertions(+), 21 deletions(-)

diff --git a/src/operators/multipliedoperator.jl b/src/operators/multipliedoperator.jl
index 5efff901..0ef2bf8b 100644
--- a/src/operators/multipliedoperator.jl
+++ b/src/operators/multipliedoperator.jl
@@ -14,40 +14,37 @@ end
         - An function f that gives the time-dependence according to op(t) = f(t)*op
 """
 const TimedOperator{O} = MultipliedOperator{O,<:Function}
+TimedOperator(x) = MultipliedOperator(x, t -> One())
 
 """
     Structure representing a time-independent operator that will be multiplied with a constant coefficient. Consists of
         - An operator (MPO, Hamiltonian, ...)
         - A number f that gets multiplied with the operator
 """
-const UntimedOperator{O} = MultipliedOperator{O,<:Union{Real,One}}
-
-#constructors for (un)TimedOperator
-TimedOperator(x::O, f::F) where {F<:Function,O} = MultipliedOperator(x, f)
-UntimedOperator(x::O, c::C) where {C<:Union{Real,One},O} = MultipliedOperator(x, c)
-
-TimedOperator(x) = TimedOperator(x, t -> One())
-UntimedOperator(x) = UntimedOperator(x, One())
+const UntimedOperator{O} = MultipliedOperator{O,<:Number}
+UntimedOperator(x) = MultipliedOperator(x, One())
 
 # Holy traits
-TimeDependence(x::TimedOperator) = TimeDependent()
+TimeDependence(::TimedOperator) = TimeDependent()
 
 # For internal use only
 _eval_at(x::UntimedOperator) = x.f * x.op
-_eval_at(x::UntimedOperator, ::Number) = x #_eval_at(x)
-_eval_at(x::TimedOperator, t::Number) = UntimedOperator(x.op, x.f(t))
+_eval_at(x::UntimedOperator, ::Number) = x
+_eval_at(x::TimedOperator, t::Number) = MultipliedOperator(x.op, x.f(t))
 
 # For users
 (x::UntimedOperator)() = _eval_at(x)
 (x::TimedOperator)(t::Number) = _eval_at(x, t)
 
 # what to do when we multiply by a scalar
-Base.:*(op::UntimedOperator, b::Number) = UntimedOperator(op.op, b * op.f)
-Base.:*(op::TimedOperator, b::Number) = TimedOperator(op.op, t -> b * op.f(t))
-Base.:*(b::Number, op::MultipliedOperator) = op * b
+Base.:*(op::UntimedOperator, b::Number) = MultipliedOperator(op.op, b * op.f)
+Base.:*(op::TimedOperator, b::Number) = MultipliedOperator(op.op, t -> b * op.f(t))
+Base.:*(b, op::MultipliedOperator) = op * b
+
+# slightly dangerous
+Base.:*(op::TimedOperator, g::Function) = MultipliedOperator(op.op, t -> g(t) * op.f(t)) 
+Base.:*(op::UntimedOperator, g::Function) = MultipliedOperator(op.op, t -> g(t) * op.f)
 
-Base.:*(op::TimedOperator, g::Function) = TimedOperator(op.op, t -> g(t) * op.f(t)) #slightly dangerous
-Base.:*(g::Function, op::TimedOperator) = op * g
 
 # don't know a better place to put this
 # environment for MultipliedOperator
diff --git a/src/operators/timedependence.jl b/src/operators/timedependence.jl
index 14081920..363b9eb2 100644
--- a/src/operators/timedependence.jl
+++ b/src/operators/timedependence.jl
@@ -1,7 +1,8 @@
 # Holy traits to differentiate between time dependent and time independent types
 
-struct TimeDependent end
-struct NotTimeDependent end
+abstract type TimeDependence end
+struct TimeDependent <: TimeDependence end
+struct NotTimeDependent <: TimeDependence end
 
 TimeDependence(x) = NotTimeDependent()
 istimed(::TimeDependent) = true
diff --git a/test/algorithms.jl b/test/algorithms.jl
index 0045cc01..e0bd5a5e 100644
--- a/test/algorithms.jl
+++ b/test/algorithms.jl
@@ -109,7 +109,7 @@ end
         @test (3 + 1.55 - 0.1) * sum(E₀) ≈ sum(E) atol = 1e-2
     end
 
-    Ht = TimedOperator(H, t -> 4) + UntimedOperator(H, 1.45)
+    Ht = MultipliedOperator(H, t -> 4) + MultipliedOperator(H, 1.45)
 
     @testset "Finite TimeDependent LazySum $(alg isa TDVP ? "TDVP" : "TDVP2")" for alg in
                                                                                    algs
@@ -139,7 +139,7 @@ end
         @test (3 + 1.55 - 0.1) * sum(E₀) ≈ sum(E) atol = 1e-2
     end
 
-    Ht = TimedOperator(H, t -> 4) + UntimedOperator(H, 1.45)
+    Ht = MultipliedOperator(H, t -> 4) + MultipliedOperator(H, 1.45)
 
     @testset "Infinite TimeDependent LazySum" begin
         ψ, envs = timestep(ψ₀, Ht(1.0), 0.0, dt, TDVP())
diff --git a/test/operators.jl b/test/operators.jl
index 18f3267d..39d44f7d 100644
--- a/test/operators.jl
+++ b/test/operators.jl
@@ -219,7 +219,7 @@ vspaces = (ℙ^10, Rep[U₁]((0 => 20)), Rep[SU₂](1 => 10, 3 => 5, 5 => 1))
     end
 
     fs = [t -> 3t, 2, 1]
-    Hts = [TimedOperator(H1, fs[1]), UntimedOperator(H2, fs[2]), H3]
+    Hts = [MultipliedOperator(H1, fs[1]), MultipliedOperator(H2, fs[2]), H3]
     summedH = LazySum(Hts)
     t = 1.1
     summedH_at = summedH(t)