Problem with for loops over user-defined structures - julia

Question

I have structures defined as:
struct CLocation{T<:Real}
x::Array{T,1}
y::Array{T,1}
z::Array{T,1}
end
struct CSize{T<:Real}
x::Array{T,1}
y::Array{T,1}
z::Array{T,1}
end
struct FLocation{T<:Real}
x::Array{T,1}
y::Array{T,1}
z::Array{T,1}
end
struct MStructure
dimension::Real
dims::Array{Int,1}
csize::CSize
ccenters::CLocation
fcenters::FLocation
corner::Array{Int,1}
edge::Array{Int,1}
end
struct CValue # {T<:Real}
domain::MStructure
value::Union{Array{<:Real}, DenseArray{Bool}} #Union{Array{T}, BitArray{}}
end
With operators for these structures:
for f in [:+, :-, :*, :/, :^, :(==), :>, :(>=), :<, :(<=)]
#eval function $f(a::CValue, b::CValue)
return CValue(a.domain, $f.(a.value, b.value))
end
end
for f in [:+, :-, :*, :/, :^, :(==), :>, :(>=), :<, :(<=)]
#eval function $f(a::CValue, b::Real)
return CValue(a.domain, $f.(a.value, b))
end
end
for f in [:+, :-, :*, :/, :^, :(==), :>, :(>=), :<, :(<=)]
#eval function $f(a::Real, b::CValue)
return CValue(b.domain, $f.(a, b.value))
end
end
I have two types of variables: val::Cvalue and vec::Vector{Cvalue}(undef,N)
I am trying to loop over them to perform summations, and I have success when implemeting:
function calc_sum(N,vec,val)
for i in 1:N
val = val + vec[i]
end
return val
end
Where I have initialized val as 0
Is there a more succinct way to perform this loop? Preferably in the format of: val = [val + vec[i] for i in 1:N]
which returns a vector of type Cvalue, when my intention is that val is simply of type Cvalue
I have tried val = (val + vec[i] for i in 1:N) with no success.

Answer 1

In Julia 1.6 and later you can use sum(vec; init = val).
In older versions you can use reduce(+, vec; init = val) or foldl(+, vec; init = val) if + is non associative.
If you want to keep enumeration, then you can do something like foldl((acc, i) -> vec[i] + acc, 1:length(vec); init = val) or equivalently
foldl(1:length(vec); init = val) do acc, i
acc + vec[i]
end