tables integration (JuliaArrays#12)

* tables integration

* tests

* removed fallback constructor

* update requires

* fix requires

* add test dependency

Author: Pietro Vertechi

REQUIRE

@@ -1 +1,2 @@
-julia 0.7-
+julia 0.7
+Requires

src/StructArrays.jl

@@ -1,8 +1,13 @@
 module StructArrays
 
+import Requires
 export StructArray
 
 include("structarray.jl")
 include("utils.jl")
 
+function __init__()
+    Requires.@require Tables="bd369af6-aec1-5ad0-b16a-f7cc5008161c" include("tables.jl")
+end
+
 end # module

src/tables.jl

@@ -0,0 +1,12 @@
+Tables.istable(::Type{<:StructArray}) = true
+Tables.rowaccess(::Type{<:StructArray}) = true
+Tables.columnaccess(::Type{<:StructArray}) = true
+
+Tables.rows(s::StructArray) = s
+Tables.columns(s::StructArray) = columns(s)
+
+@generated function Tables.schema(s::StructArray{T}) where {T}
+    names = fieldnames(T)
+    types = map(sym -> fieldtype(T, sym), names)
+    :(Tables.Schema($names, $types))
+end

test/REQUIRE

@@ -0,0 +1 @@
+Tables

test/runtests.jl

@@ -1,4 +1,5 @@
 using StructArrays
+import Tables
 using Test
 
 # write your own tests here
@@ -103,3 +104,16 @@ end
     a = StructArray{ComplexF64}(Float64[], Float64[])
     @test sort(collect(propertynames(a))) == [:im, :re]
 end
+
+@testset "tables" begin
+    s = StructArray([(a=1, b="test")])
+    @test Tables.schema(s) == Tables.Schema((:a, :b), (Int, String))
+    @test Tables.rows(s)[1].a == 1
+    @test Tables.rows(s)[1].b == "test"
+    @test Tables.columns(s).a == [1]
+    @test Tables.columns(s).b == ["test"]
+    @test Tables.istable(s)
+    @test Tables.rowaccess(s)
+    @test Tables.columnaccess(s)
+end
+