IntArrays.jl is a package for packed integer arrays.
An array type, `IntArray`

, is exported from this package and some methods in
`Base`

are extended for it.

The `IntArray`

type is defined as follows:

```
type IntArray{w,T<:Unsigned,n} <: AbstractArray{T,n}
```

where

`w`

: the bit width of integers (i.e. the number of bits to encode an integer)`T`

: the type of integers`n`

: the number of dimensions in the array.

This works like normal arrays, but each element is packed in a buffer as compact as possible.
That means the total memory footprint can be reduced if you specify small `w`

value: the total size is about `w * length(int_array)`

bits.
You can think of it as a generalization of `BitArray`

defined in the standard library:
`IntArray`

can store any (unsigned) integers, whereas `BitArray`

is restricted
to `Bool`

.
It is your responsibility to keep values between `0`

and `2^w-1`

; otherwise
values will be truncated to `w`

bits with no warning.

Like `Vector{T}`

and `Matrix{T}`

in `Base`

, `IntVector{w,T}`

and `IntMatrix{w,T}`

are also defined as a type alias of `IntArray{w,T,n}`

.

```
julia> using IntArrays
julia> ivec = IntVector{2}([0x00, 0x01, 0x03, 0x02])
4-element IntArrays.IntArray{2,UInt8,1}:
0x00
0x01
0x03
0x02
julia> ivec[2]
0x01
julia> ivec[2] = 0x03
0x03
julia> ivec[2]
0x03
```

See tutorial.ipynb for more details.

- Make it behave more like usual arrays.
- Store signed integers.

08/12/2015

8 months ago

70 commits