Perf: Specialize fn in rmap and rmaptype

Also avoid use of `map` on `NamedTuple`s as it doesn't specialize `f`.

src/RecursiveApply/RecursiveApply.jl

@@ -14,26 +14,29 @@ export ⊞, ⊠, ⊟
 
 Recursively apply `fn` to each element of `X`
 """
-rmap(fn, X) = fn(X)
-rmap(fn, X, Y) = fn(X, Y)
-rmap(fn, X::Tuple) = map(x -> rmap(fn, x), X)
-rmap(fn, X::Tuple, Y::Tuple) = map((x, y) -> rmap(fn, x, y), X, Y)
-rmap(fn, X::NamedTuple) = map(x -> rmap(fn, x), X)
-rmap(fn, X::NamedTuple{names}, Y::NamedTuple{names}) where {names} =
-    map((x, y) -> rmap(fn, x, y), X, Y)
+rmap(fn::F, X) where {F} = fn(X)
+rmap(fn::F, X, Y) where {F} = fn(X, Y)
+rmap(fn::F, X::Tuple) where {F} = map(x -> rmap(fn, x), X)
+rmap(fn::F, X::Tuple, Y::Tuple) where {F} = map((x, y) -> rmap(fn, x, y), X, Y)
+rmap(fn::F, X::NamedTuple{names}) where {F, names} =
+    NamedTuple{names}(rmap(fn, Tuple(X)))
+rmap(fn::F, X::NamedTuple{names}, Y::NamedTuple{names}) where {F, names} =
+    NamedTuple{names}(rmap(fn, Tuple(X), Tuple(Y)))
 
 """
     rmaptype(fn, T)
 
 The return type of `rmap(fn, X::T)`.
 """
-rmaptype(fn, ::Type{T}) where {T} = fn(T)
-rmaptype(fn, ::Type{T}) where {T <: Tuple} =
+rmaptype(fn::F, ::Type{T}) where {F, T} = fn(T)
+rmaptype(fn::F, ::Type{T}) where {F, T <: Tuple} =
     Tuple{map(fn, tuple(T.parameters...))...}
-rmaptype(fn, ::Type{T}) where {T <: NamedTuple{names, tup}} where {names, tup} =
+rmaptype(
+    fn::F,
+    ::Type{T},
+) where {F, T <: NamedTuple{names, tup}} where {names, tup} =
     NamedTuple{names, rmaptype(fn, tup)}
 
-
 """
     rmul(w, X)
     w ⊠ X
@@ -66,7 +69,6 @@ const ⊟ = rsub
 
 rdiv(X, w::Number) = rmap(x -> x / w, X)
 
-
 """
     rmuladd(w, X, Y)
 
@@ -76,7 +78,6 @@ rmuladd(w::Number, X, Y) = rmap((x, y) -> muladd(w, x, y), X, Y)
 rmuladd(X, w::Number, Y) = rmap((x, y) -> muladd(x, w, y), X, Y)
 rmuladd(w::Number, x::Number, y::Number) = muladd(w, x, y)
 
-
 """
     rmatmul1(W, S, i, j)