Julia - implementing to_index(::Symbol) - julia

Question

The following fails on load. It says the problem is with the to_index method but it only happens when using the colon operator.
S = InputOhlcSeries{Int}(5)
push!(S, 0,0,0,1)
push!(S, 0,0,0,2)
push!(S, 0,0,0,3)
push!(S, 0,0,0,4)
push!(S, 0,0,0,5)
push!(S, 0,0,0,6)
#assert S[end, :close] == 6 # Works fine
#assert S[:, 4] == [2,3,4,5,6] # Works fine
#assert S[:, :close] == [2,3,4,5,6] # Will fail here
ERROR: LoadError: LoadError: ArgumentError: invalid index: close of type Symbol
Stacktrace:
[1] to_index(::Symbol) at ./indices.jl:270
[2] to_index(::InputOhlcSeries{Int64}, ::Symbol) at ./indices.jl:247
[3] to_indices at ./indices.jl:298 [inlined]
[4] to_indices at ./indices.jl:294 [inlined]
[5] getindex(::InputOhlcSeries{Int64}, ::Function, ::Symbol) at ./abstractarray.jl:927
[6] top-level scope at none:0
[7] include at ./boot.jl:326 [inlined]
using Match
mutable struct InputOhlcSeries{T} <: AbstractArray{T,2}
data::CircularBuffer{Vector{T}}
function InputOhlcSeries{T}(length::Int) where T
data = CircularBuffer{Vector{T}}(length)
fill!(data, [0,0,0,0])
new{T}(data)
end
end
#inline Base.getindex(S::InputOhlcSeries, i::Int, j::Int) = S.data[i][j]
#inline Base.setindex!(S::InputOhlcSeries, value, i::Int, j::Int) = S.data[i][j] = value
Base.size(S::InputOhlcSeries) = (length(S.data), 4)
Base.eltype(::Type{InputOhlcSeries{T}}) where {T} = T
#inline Base.push!(S::InputOhlcSeries, open, high, low, close) = push!(S.data, [open, high, low, close])
#inline function Base.getindex(S::InputOhlcSeries, r::Int, c::Symbol)
S[r, to_index(c)]
end
#inline function Base.setindex!(S::InputOhlcSeries, value, r::Int, c::Symbol)
S[r, to_index(c)] = value
end
#inline function to_index(r::Symbol)::Int
#match r begin
:open => 1
:high => 2
:low => 3
:close => 4
_ => throw(ArgumentError("Expected one of :open, :high, :low, :close"))
end
end

Answer 1

Made the following mods:
import Base: to_index
#inline Base.getindex(S::InputOhlcSeries, r::Int, c::Symbol) = S[r, to_index(S, c)]
#inline function Base.setindex!(S::InputOhlcSeries, value, r::Int, c::Symbol)
S[r, to_index(S, c)] = value
end
#inline Base.push!(S::InputOhlcSeries, open, high, low, close) = push!(S.data, [open, high, low, close])
function to_index(S::InputOhlcSeries, s::Symbol)
#match s begin
:open => 1
:high => 2
:low => 3
:close => 4
_ => throw(ArgumentError("Expected one of :open, :high, :low, :close"))
end
end