index.jl

#define cartesian index

using Base:  LinearIndices, CartesianIndices #LinearIndex, CartesianIndex #,

# Pyramid #1

##1. Unit Range (::Int64 : ::Int64)

##2. Array

##3. View

##4. SubArray

##Pyramid #2

##1. Unit Range (::Int64 : ::Int64)

##2. cartesianIndex

##3.Index

##3.1. LinearIndices
println("LinearIndices(1:9) = ", Base.LinearIndices(1:9) )

 a=1 :: Int64
 b=9 :: Int64

unitRange = a:b

##3.2. cartesianIndex
function getCartesianIndex( unitRange  ) #::Base.AbstracUnitRange)
    CartesianIndex(unitRange )
end

cartesianIndex(index::Integer...) = Base.CartesianIndex(index)

#l
#  :: Base.CartesianIndices
function getIndex(inds, arr)

    # LinearIndices(inds ) -> R
     iter = Base.CartesianIndices(axes(arr))

     #NI = inc(i.I, iter.indices)

     #I = #Base.inc
     #I = (iter.I, CartesianIndices.indices) # caretesian has no field I
     #I = (iter, CartesianIndices.indices) #UnionAll
     I = iter
     I
end


function getindices2(a :: Int64 , b :: Int64, arr )

    firstIndex = getIndex(a , arr ) #firstIndex(findall(x -> x == a, arr ))
    lastIndex = getIndex(b , arr ) #lastindex(findall(x -> x == b, arr ))

    idxA, idxB = firstIndex, lastIndex
    idxA, idxB
end
ar = [3,2,1]
println(  CartesianIndices(axes(ar) ))