From 579e20478c41327590c6601c5135dc020e14cf44 Mon Sep 17 00:00:00 2001
From: Jim Pivarski <jpivarski@gmail.com>
Date: Tue, 8 Aug 2023 18:53:11 -0500
Subject: [PATCH] Empty constructors and appending methods.

---
 src/AwkwardArray.jl | 24 ++++++++++++++++++++++--
 test/runtests.jl    | 40 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+), 2 deletions(-)

diff --git a/src/AwkwardArray.jl b/src/AwkwardArray.jl
index 1fe1271..e89bb2e 100644
--- a/src/AwkwardArray.jl
+++ b/src/AwkwardArray.jl
@@ -10,7 +10,7 @@ Index64 = AbstractArray{Int64,1}
 
 ### Content ##############################################################
 
-abstract type Content <: AbstractArray{T where T<:Any,1} end
+abstract type Content <: AbstractArray{T where T,1} end
 
 function Base.iterate(layout::Content)
     start = firstindex(layout)
@@ -37,10 +37,14 @@ end
 
 ### PrimitiveArray #######################################################
 
-struct PrimitiveArray{ARRAY<:AbstractArray{T,1} where {T<:Any}} <: Content
+struct PrimitiveArray{T,ARRAY<:AbstractArray{T,1}} <: Content
     data::ARRAY
 end
 
+function PrimitiveArray{T}() where {T}
+    PrimitiveArray(Vector{T}([]))
+end
+
 function is_valid(layout::PrimitiveArray)
     true
 end
@@ -69,6 +73,10 @@ function Base.:(==)(layout1::PrimitiveArray, layout2::PrimitiveArray)
     layout1.data == layout2.data
 end
 
+function push!(layout::PrimitiveArray{T}, x::T) where {T}
+    Base.push!(layout.data, x)
+end
+
 ### ListOffsetArray ######################################################
 
 struct ListOffsetArray{INDEX<:Union{Index32,IndexU32,Index64},CONTENT<:Content} <: Content
@@ -76,6 +84,13 @@ struct ListOffsetArray{INDEX<:Union{Index32,IndexU32,Index64},CONTENT<:Content}
     content::CONTENT
 end
 
+function ListOffsetArray{
+    INDEX,
+    CONTENT,
+}() where {INDEX<:Union{Index32,IndexU32,Index64}} where {CONTENT<:Content}
+    AwkwardArray.ListOffsetArray(INDEX([0]), CONTENT())
+end
+
 function is_valid(layout::ListOffsetArray)
     if length(layout.offsets) < 1
         return false
@@ -126,4 +141,9 @@ function Base.:(==)(layout1::ListOffsetArray, layout2::ListOffsetArray)
     end
 end
 
+function end_list!(layout::ListOffsetArray)
+    Base.push!(layout.offsets, length(layout.content))
+    layout.content
+end
+
 end
diff --git a/test/runtests.jl b/test/runtests.jl
index 113445c..b91044b 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -18,6 +18,22 @@ using Test
         @test tmp == 16.5
     end
 
+    begin
+        layout = AwkwardArray.PrimitiveArray{Float64}()
+        @test length(layout) == 0
+        AwkwardArray.push!(layout, 1.1)
+        @test length(layout) == 1
+        AwkwardArray.push!(layout, 2.2)
+        @test length(layout) == 2
+        AwkwardArray.push!(layout, 3.3)
+        @test length(layout) == 3
+        AwkwardArray.push!(layout, 4.4)
+        @test length(layout) == 4
+        AwkwardArray.push!(layout, 5.5)
+        @test length(layout) == 5
+        @test layout == AwkwardArray.PrimitiveArray([1.1, 2.2, 3.3, 4.4, 5.5])
+    end
+
     begin
         layout = AwkwardArray.ListOffsetArray(
             [0, 3, 3, 5],
@@ -64,4 +80,28 @@ using Test
         @test !AwkwardArray.is_valid(layout)
     end
 
+    begin
+        layout = AwkwardArray.ListOffsetArray{
+            AwkwardArray.Index64,
+            AwkwardArray.PrimitiveArray{Float64},
+        }()
+        sublayout = layout.content
+        @test length(layout) == 0
+        AwkwardArray.push!(sublayout, 1.1)
+        AwkwardArray.push!(sublayout, 2.2)
+        AwkwardArray.push!(sublayout, 3.3)
+        AwkwardArray.end_list!(layout)
+        @test length(layout) == 1
+        AwkwardArray.end_list!(layout)
+        @test length(layout) == 2
+        AwkwardArray.push!(sublayout, 4.4)
+        AwkwardArray.push!(sublayout, 5.5)
+        AwkwardArray.end_list!(layout)
+        @test length(layout) == 3
+        @test layout == AwkwardArray.ListOffsetArray(
+            [0, 3, 3, 5],
+            AwkwardArray.PrimitiveArray([1.1, 2.2, 3.3, 4.4, 5.5]),
+        )
+    end
+
 end