specialize ODEProblem remake for compile times

src/remake.jl

@@ -33,19 +33,37 @@ end
 
 isrecompile(prob::ODEProblem{iip}) where {iip} = (prob.f isa ODEFunction) ? !isfunctionwrapper(prob.f.f) : true
 
-function remake(thing::ODEProblem; kwargs...)
-  T = remaker_of(thing)
-  tup = merge(merge(struct_as_namedtuple(thing),thing.kwargs),kwargs)
-  if !isrecompile(thing)
-    if isinplace(thing)
-      f = wrapfun_iip(unwrap_fw(tup.f.f),(tup.u0,tup.u0,tup.p,tup.tspan[1]))
+function remake(prob::ODEProblem; f=missing,
+                                  u0=missing,
+                                  tspan=missing,
+                                  p=missing,
+                                  kwargs...)
+  if f === missing
+    f = prob.f
+  elseif !isrecompile(prob)
+    if isinplace(prob)
+      f = wrapfun_iip(unwrap_fw(f),(u0,u0,p,tspan[1]))
     else
-      f = wrapfun_oop(unwrap_fw(tup.f.f),(tup.u0,tup.p,tup.tspan[1]))
+      f = wrapfun_oop(unwrap_fw(f),(u0,p,tspan[1]))
     end
-    tup2 = (f = convert(ODEFunction{isinplace(thing)},f),)
-    tup = merge(tup, tup2)
+    f = convert(ODEFunction{isinplace(prob)},f)
+  elseif prob.f isa ODEFunction # avoid the SplitFunction etc. cases
+    f = convert(ODEFunction{isinplace(prob)},f)
+  end
+
+  if u0 === missing
+    u0 = prob.u0
+  end
+
+  if tspan === missing
+    tspan = prob.tspan
+  end
+
+  if p === missing
+    p = prob.p
   end
-  T(; tup...)
+
+  ODEProblem{isinplace(prob)}(f,u0,tspan,p,prob.problem_type;prob.kwargs..., kwargs...)
 end
 
 function remake(thing::AbstractJumpProblem; kwargs...)

test/downstream/symbol_indexing.jl

@@ -8,14 +8,14 @@ eqs = [D(x) ~ σ*(y-x),
        D(y) ~ x*(ρ-z)-y,
        D(z) ~ x*y - β*z]
 
-lorenz1 = ODESystem(eqs,name=:lorenz1)
-lorenz2 = ODESystem(eqs,name=:lorenz2)
+@named lorenz1 = ODESystem(eqs)
+@named lorenz2 = ODESystem(eqs)
 
 @parameters γ
 @variables a(t) α(t)
 connections = [0 ~ lorenz1.x + lorenz2.y + a*γ,
                α ~ 2lorenz1.x + a*γ]
-sys = ODESystem(connections,t,[a,α],[γ],systems=[lorenz1,lorenz2])
+@named sys = ODESystem(connections,t,[a,α],[γ],systems=[lorenz1,lorenz2])
 sys_simplified = structural_simplify(sys)
 
 u0 = [lorenz1.x => 1.0,