A few updates

[jminardi]

This PR brings in a few updates:

1. Paths now print themselves as a valid constructor (see output below)

2. Paths can now be constructed from a vector of tuples:

   julia> p = Path([(0, 0), (0, 10), (10, 10)])
   Path([(0,0), (0,10), (10,10)])
   

2a. Tuples can be pushed into paths
3. Paths can be compared for equality
4. Some tests of this new functionality

[dreammaker]

Extra prints should be removed. For testing, silent == all good.

[sjkelly]

We have a lot of these. We can keep everything silent by making an IOBuffer and checking string equality:

julia> p = Path(5)
(0,0), (0,0), (0,0), (0,0), (0,0)

julia> a = IOBuffer()
IOBuffer(data=UInt8[...], readable=true, writable=true, seekable=true, append=false, size=0, maxsize=Inf, ptr=1, mark=-1)

julia> show(a, p)

julia> ASCIIString(a.data)
"(0,0), (0,0), (0,0), (0,0), (0,0)"

[jminardi]

I've implemented the tests using an IOBuffer

[sjkelly]

This needs tests.

Apparently the PolyTree is just an array of PolyNodes: https://github.com/Voxel8/Clipper.jl/blob/6a3cce9ea409d7b4977024e3bbee1830955cb205/src/clipper_cpp.jl#L138

It would be convenient if we could define getindex too.

[jminardi]

I wrote a test for child_count.

I am struggling with implementing getindex. Here is what I tried:

@inline function Base.getindex(p::__ClipperPolyTree, i::Integer)
    icxx"$p[$i-1];"
end

I get the following error when I try to call getindex

ERROR: LoadError: MethodError: `getindex` has no method matching getindex(::Cxx.CppValue{Cxx.CppBaseType{symbol("ClipperLib::PolyTree")},(false,false,false)}, ::Int64)
Closest candidates are:
  getindex(::(Any...,), ::Int64)
  getindex(::(Any...,), ::Real)
  getindex{T}(::FloatRange{T}, ::Integer)

[dreammaker]

PolyTree is a subclass of PolyNode, so I don't think getindex makes sense. See definition here.

[jminardi]

I've removed getindex from this PR. If we later decide we want it we can add it back in in another PR.

[jminardi]

Things that are still holding this PR up:

1. Instantiating a Paths() object from an array of Path() objects
2. Implmenting getindex for PolyTrees

[dreammaker]

I don't think it's good practice to put newlines in show() output. If it's nested inside another object, the whole output is broken.

[jminardi]

Julia's arrays use newlines in their output:

julia> a = [1 2;3 4]
2x2 Array{Int64,2}:
 1  2
 3  4

I think newlines make the arrays significantly easier to read, and I think the same can be said about Paths()

[sjkelly]

I think under the covers the REPL's 'P' is println:

julia> 6
6

julia> print(6)
6
julia> 

[jminardi]

According to this show() is being deprecated in favor of write() anyway. It seems like println() just calls show() under the covers.

[jminardi]

@show still uses newlines for arrays:

julia> @show a
a = [1 2
 3 4]

[jminardi]

Ok, I think this PR is ready to merge

[sjkelly]

LGTM 👍