Cleanup integration w/ queryverse; provide Tables.DataValueUnwrapper …

…for sinks to unwrap potentially DataValue-based NamedTuples (#16)

src/Tables.jl

@@ -6,7 +6,6 @@ export rowtable, columntable
 
 function __init__()
     @require DataValues="e7dc6d0d-1eca-5fa6-8ad6-5aecde8b7ea5" include("datavalues.jl")
-    @require Query="1a8c2f83-1ff3-5112-b086-8aa67b057ba1" include("enumerable.jl")
     @require CategoricalArrays="324d7699-5711-5eae-9e2f-1d82baa6b597" begin
         using .CategoricalArrays
         allocatecolumn(::Type{CategoricalString{R}}, rows) where {R} = CategoricalArray{String, 1, R}(undef, rows)
@@ -178,4 +177,7 @@ include("namedtuples.jl")
 # generic fallback definitions
 include("fallbacks.jl")
 
+# integration with queryverse
+include("query.jl")
+
 end # module

src/datavalues.jl

@@ -1,23 +1,10 @@
 using .DataValues
 
-# DataValue-compatible row iteration for Data.Sources
+# DataValue overloads for query.jl definitions
 nondatavaluetype(::Type{DataValue{T}}) where {T} = Union{T, Missing}
-nondatavaluetype(::Type{T}) where {T} = T
-Base.@pure function nondatavaluetype(::Type{NT}) where {NT <: NamedTuple{names}} where {names}
-    TT = Tuple{Any[ nondatavaluetype(fieldtype(NT, i)) for i = 1:fieldcount(NT) ]...}
-    return NamedTuple{names, TT}
-end
-
-unwrap(x) = x
 unwrap(x::DataValue) = isna(x) ? missing : DataValues.unsafe_get(x)
-
 datavaluetype(::Type{T}) where {T <: DataValue} = T
-datavaluetype(::Type{T}) where {T} = T
 datavaluetype(::Type{Union{T, Missing}}) where {T} = DataValue{T}
-Base.@pure function datavaluetype(::Tables.Schema{names, types}) where {names, types}
-    TT = Tuple{Any[ datavaluetype(fieldtype(types, i)) for i = 1:fieldcount(types) ]...}
-    return NamedTuple{names, TT}
-end
 
 struct DataValueRowIterator{NT, S}
     x::S
@@ -26,6 +13,7 @@ DataValueRowIterator(::Type{NT}, x::S) where {NT <: NamedTuple, S} = DataValueRo
 
 "Returns a DataValue-based NamedTuple-iterator"
 DataValueRowIterator(::Type{Schema{names, types}}, x::S) where {names, types, S} = DataValueRowIterator{datavaluetype(NamedTuple{names, types}), S}(x)
+
 function datavaluerows(x)
     r = Tables.rows(x)
     #TODO: add support for unknown schema
@@ -55,6 +43,9 @@ function Base.iterate(rows::DataValueRowIterator{NT, S}, st=()) where {NT <: Nam
     end
 end
 
+# Alternative lazy row implementation; currently though, Query.jl relies on
+# being able to infer return types via all the type information of NamedTuples
+
 # function Base.iterate(rows::DataValueRowIterator{NT}, st=()) where {NT}
 #     state = iterate(rows.x, st...)
 #     state === nothing && return nothing

src/enumerable.jl → src/query.jl

@@ -1,17 +1,26 @@
-using .Query
+nondatavaluetype(::Type{T}) where {T} = T
+datavaluetype(::Type{T}) where {T} = T
 
-@static if isdefined(Query.QueryOperators, :Enumerable)
+Base.@pure function nondatavaluetype(::Type{NT}) where {NT <: NamedTuple{names}} where {names}
+    TT = Tuple{Any[ nondatavaluetype(fieldtype(NT, i)) for i = 1:fieldcount(NT) ]...}
+    return NamedTuple{names, TT}
+end
 
-import .Query.QueryOperators: Enumerable
+Base.@pure function datavaluetype(::Tables.Schema{names, types}) where {names, types}
+    TT = Tuple{Any[ datavaluetype(fieldtype(types, i)) for i = 1:fieldcount(types) ]...}
+    return NamedTuple{names, TT}
+end
 
-Tables.istable(::Type{<:Enumerable}) = true
-Tables.rowaccess(::Type{<:Enumerable}) = true
-Tables.rows(e::Enumerable) = DataValueUnwrapper(e)
+unwrap(x) = x
 
 struct DataValueUnwrapper{S}
     x::S
 end
 
+Tables.istable(::Type{<:DataValueUnwrapper}) = true
+Tables.rowaccess(::Type{<:DataValueUnwrapper}) = true
+Tables.rows(x::DataValueUnwrapper) = x
+
 function Tables.schema(dv::DataValueUnwrapper)
     eT = eltype(dv.x)
     !(eT <: NamedTuple) && return nothing
@@ -34,6 +43,4 @@ end
 
 Base.getproperty(d::DataValueUnwrapRow, ::Type{T}, col::Int, nm::Symbol) where {T} = unwrap(getproperty(getfield(d, 1), T, col, nm))
 Base.getproperty(d::DataValueUnwrapRow, nm::Symbol) = unwrap(getproperty(getfield(d, 1), nm))
-Base.propertynames(d::DataValueUnwrapRow) = propertynames(getfield(d, 1))
-
-end # isdefined
+Base.propertynames(d::DataValueUnwrapRow) = propertynames(getfield(d, 1))

test/runtests.jl

@@ -87,7 +87,7 @@ end
 
     @test Tables.buildcolumns(nothing, rt) == nt
     @test Tables.columntable(nothing, nt) == nt
-    
+
     # append
     nt2 = columntable(nt, rt)
     @test Tables.rowcount(nt2) == 6
@@ -195,19 +195,19 @@ end
     rt2 = collect(dv)
     @test rt2[1] == (a = 1, b = DataValue{Float64}(4.0), c = "7")
 
-    ei = QueryOperators.EnumerableIterable{eltype(dv), typeof(dv)}(dv)
+    ei = Tables.DataValueUnwrapper(QueryOperators.EnumerableIterable{eltype(dv), typeof(dv)}(dv))
     nt = ei |> columntable
     @test isequal(rt, nt)
     rt3 = ei |> rowtable
     @test isequal(rt |> rowtable, rt3)
 
     # rt = [(a=1, b=4.0, c="7"), (a=2, b=5.0, c="8"), (a=3, b=6.0, c="9")]
-    mt = ei |> y->QueryOperators.map(y, x->(a=x.b, c=x.c), Expr(:block))
+    mt = Tables.DataValueUnwrapper(ei.x |> y->QueryOperators.map(y, x->(a=x.b, c=x.c), Expr(:block)))
     @inferred (mt |> columntable)
     @inferred (mt |> rowtable)
 
     # uninferrable case
-    mt = ei |> y->QueryOperators.map(y, x->(a=x.a, c=x.c), Expr(:block))
+    mt = Tables.DataValueUnwrapper(ei.x |> y->QueryOperators.map(y, x->(a=x.a, c=x.c), Expr(:block)))
     @test (mt |> columntable) == (a = Real[1, 2.0, 3], c = ["7", "8", "9"])
     @test length(mt |> rowtable) == 3
 end