fix #51

Author: sl-solution

src/byrow/row_functions.jl

@@ -33,6 +33,11 @@ function row_sum(ds::AbstractDataset, f::Function,  cols = names(ds, Union{Missi
     colsidx = multiple_getindex(index(ds), cols)
     CT = mapreduce(eltype, promote_type, view(_columns(ds),colsidx))
     T = Core.Compiler.return_type(f, Tuple{CT})
+	CT = nonmissingtype(T)
+	CT <: Base.SmallSigned ? CT = Int : nothing
+	CT <: Base.SmallUnsigned ? CT = UInt : nothing
+	CT <: Bool ? CT = Int : nothing
+	T = Union{Missing, CT}
     init0 = _missings(T, nrow(ds))
 
     if threads
@@ -63,6 +68,11 @@ function row_prod(ds::AbstractDataset, f::Function, cols = names(ds, Union{Missi
     colsidx = multiple_getindex(index(ds), cols)
     CT = mapreduce(eltype, promote_type, view(_columns(ds),colsidx))
     T = Core.Compiler.return_type(f, Tuple{CT})
+	CT = nonmissingtype(T)
+	CT <: Base.SmallSigned ? CT = Int : nothing
+	CT <: Base.SmallUnsigned ? CT = UInt : nothing
+	CT <: Bool ? CT = Int : nothing
+	T = Union{Missing, CT}
     init0 = _missings(T, nrow(ds))
 
     if threads

test/byrow.jl

@@ -341,6 +341,14 @@
     @test byrow(ds, join, :) == ["α111.4", "β∘125.6"]
     @test byrow(ds, join, :, delim = ",") == ["α1,1,1.4", "β∘1,2,5.6"]
     @test byrow(ds, join, :, delim = ":×:") == ["α1:×:1:×:1.4", "β∘1:×:2:×:5.6"]
+
+
+    # promoting small ints
+    ds = Dataset(x1=Int8[127,127],x2=Int8[127,-127])
+    @test byrow(ds,sum) == [254,0]
+    @test byrow(ds,prod) == [16129,-16129]
+    ds = Dataset(x1=[true,true,false],x2=[true,true,false],x3=[true,false,true])
+    @test byrow(ds,sum)==[3,2,1]
 end
 
 @testset "cum*/! - sort/!" begin