ArrayString_poc.jl

#+BEGIN_SRC jupyter-julia
struct ArrayString{Store <: AbstractVector{<:AbstractChar}} <: AbstractString
    chars::Store
end

ArrayString(str::String) = ArrayString(collect(str))
ArrayString(T, str::String) = ArrayString(T(collect(str))) 

Base.String(s::ArrayString) = String(s.chars)

function Base.show(io::IO, ::MIME"text/plain", s::ArrayString{Store}) where {Store}
    println(io, "String backed by $Store\n  ", "\"", String(s), "\"")
end

function Base.show(io::IO, s::ArrayString{Store}) where {Store}
    println(io, "\"", String(s), "\"")
end

Base.:(*)(s1::ArrayString, s2::ArrayString) = ArrayString(vcat(s1.chars, s2.chars))
Base.:(*)(ss::ArrayString...) = *((ss[1] * ss[2]), ss[3:end]...)

ArrayString("hi") * ArrayString(" ") * ArrayString("bye")
#+END_SRC

#+RESULTS:
: String backed by Array{Char,1}
:   "hi bye"

________________________________________________________________________________________________________


#+BEGIN_SRC jupyter-julia
using CUDA

function print_kernel(::MIME"text/plain", str)
    @cuprintln "ArrayString backed by CuVector"
    @cuprint " \""
    foreach(str) do char
        @cuprint Cchar(char) #CUDA.jl printing only supports Cchars
    end
    @cuprint "\""
    @cuprintln
    CUDA.cudaDeviceSynchronize()
    return nothing
end

function Base.show(io::IO, m::MIME"text/plain", s::ArrayString{<:CUDA.AbstractGPUArray}) 
    @cuda print_kernel(m, s.chars)
end

ArrayString(cu, "this")     * 
    ArrayString(cu, " is")  * 
    ArrayString(cu, " on")  * 
    ArrayString(cu, " the") * 
    ArrayString(cu, " gpu")
#+END_SRC

#+RESULTS:
: ArrayString backed by CuVector
:  "this is on the gpu"