Re: [julia-users] Overload Base.show for a Array of specific type

[Yichao Yu]

On Fri, Oct 16, 2015 at 9:08 PM, Chris Stook <chris.st...@gmail.com> wrote:
> Is it possible to overload show for an array of a specific type?  See
> example below.
>
> In [1]:
> type a_type
>     b_element :: Int64
>     c_element :: Int64
> end
> d_array = [a_type(1,2),a_type(3,4),a_type(5,6)]
>
> Out[1]:
> 3-element Array{a_type,1}:
>  a_type(1,2)
>  a_type(3,4)
>  a_type(5,6)
>
> In [2]:
> function Base.show(io::IO, a::Array{a_type,1})
>     println(io,rpad("b_element",10),rpad("c_element",10))
>     for e in a
>         println(io,rpad(e.b_element,10),rpad(e.c_element,10))
>     end
> end
>
> Out[2]:
> show (generic function with 105 methods)
>
> In [3]:
> show(d_array)
> b_element c_element
> 1                2
> 3                4
> 5                6
>
> In [4]:
> d_array
>
> Out[4]:
> 3-element Array{a_type,1}:
>  a_type(1,2)
>  a_type(3,4)
>  a_type(5,6)
>

Quote from 
http://julia.readthedocs.org/en/latest/stdlib/io-network/#Base.writemime

> The display functions ultimately call writemime in order to write an object x 
> as a given mime type to a given I/O stream (usually a memory buffer), if 
> possible.

```
julia> type A
       end

julia> A[]
0-element Array{A,1}

julia> Base.writemime(io::IO, ::MIME"text/plain", a::Vector{A}) =
print(io, "nothing")
writemime (generic function with 26 methods)

julia> A[]
nothing
```

>
>
>
> - Chris