Fix Tables.schema definitions so row iteration with Tables.jl works (#77)

* Fix `Tables.schema(::Records)` definitions

- This makes `Tables.namedtupleiterator` and
  consequently `Tables.rowtable` work as expected.

* Document iterating over tabular records

Author: nickrobinson251

Project.toml

@@ -1,7 +1,7 @@
 name = "PowerFlowData"
 uuid = "dd99e9e3-7471-40fc-b48d-a10501125371"
 authors = "Nick Robinson <npr251@gmail.com> and contributors"
-version = "1.4.1"
+version = "1.4.2"
 
 [deps]
 DocStringExtensions = "ffbed154-4ef7-542d-bbb7-c09d3a79fcae"

docs/Manifest.toml

@@ -1,6 +1,6 @@
 # This file is machine-generated - editing it directly is not advised
 
-julia_version = "1.7.1"
+julia_version = "1.7.2"
 manifest_format = "2.0"
 
 [[deps.ANSIColoredPrinters]]
@@ -19,9 +19,9 @@ uuid = "2a0f44e3-6c83-55bd-87e4-b1978d98bd5f"
 
 [[deps.Compat]]
 deps = ["Base64", "Dates", "DelimitedFiles", "Distributed", "InteractiveUtils", "LibGit2", "Libdl", "LinearAlgebra", "Markdown", "Mmap", "Pkg", "Printf", "REPL", "Random", "SHA", "Serialization", "SharedArrays", "Sockets", "SparseArrays", "Statistics", "Test", "UUIDs", "Unicode"]
-git-tree-sha1 = "b153278a25dd42c65abbf4e62344f9d22e59191b"
+git-tree-sha1 = "9be8be1d8a6f44b96482c8af52238ea7987da3e3"
 uuid = "34da2185-b29b-5c13-b0c7-acf172513d20"
-version = "3.43.0"
+version = "3.45.0"
 
 [[deps.CompilerSupportLibraries_jll]]
 deps = ["Artifacts", "Libdl"]
@@ -33,9 +33,9 @@ uuid = "a8cc5b0e-0ffa-5ad4-8c14-923d3ee1735f"
 version = "4.1.1"
 
 [[deps.DataAPI]]
-git-tree-sha1 = "cc70b17275652eb47bc9e5f81635981f13cea5c8"
+git-tree-sha1 = "fb5f5316dd3fd4c5e7c30a24d50643b73e37cd40"
 uuid = "9a962f9c-6df0-11e9-0e5d-c546b8b5ee8a"
-version = "1.9.0"
+version = "1.10.0"
 
 [[deps.DataFrames]]
 deps = ["Compat", "DataAPI", "Future", "InvertedIndices", "IteratorInterfaceExtensions", "LinearAlgebra", "Markdown", "Missings", "PooledArrays", "PrettyTables", "Printf", "REPL", "Reexport", "SortingAlgorithms", "Statistics", "TableTraits", "Tables", "Unicode"]
@@ -45,9 +45,9 @@ version = "1.3.3"
 
 [[deps.DataStructures]]
 deps = ["Compat", "InteractiveUtils", "OrderedCollections"]
-git-tree-sha1 = "3daef5523dd2e769dad2365274f760ff5f282c7d"
+git-tree-sha1 = "d1fff3a548102f48987a52a2e0d114fa97d730f0"
 uuid = "864edb3b-99cc-5e75-8d2d-829cb0a9cfe8"
-version = "0.18.11"
+version = "0.18.13"
 
 [[deps.DataValueInterfaces]]
 git-tree-sha1 = "bfc1187b79289637fa0ef6d4436ebdfe6905cbd6"
@@ -184,25 +184,25 @@ version = "1.4.1"
 
 [[deps.Parsers]]
 deps = ["Dates"]
-git-tree-sha1 = "3b429f37de37f1fc603cc1de4a799dc7fbe4c0b6"
+git-tree-sha1 = "0044b23da09b5608b4ecacb4e5e6c6332f833a7e"
 uuid = "69de0a69-1ddd-5017-9359-2bf0b02dc9f0"
-version = "2.3.0"
+version = "2.3.2"
 
 [[deps.Pkg]]
 deps = ["Artifacts", "Dates", "Downloads", "LibGit2", "Libdl", "Logging", "Markdown", "Printf", "REPL", "Random", "SHA", "Serialization", "TOML", "Tar", "UUIDs", "p7zip_jll"]
 uuid = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
 
 [[deps.PooledArrays]]
 deps = ["DataAPI", "Future"]
-git-tree-sha1 = "28ef6c7ce353f0b35d0df0d5930e0d072c1f5b9b"
+git-tree-sha1 = "a6062fe4063cdafe78f4a0a81cfffb89721b30e7"
 uuid = "2dfb63ee-cc39-5dd5-95bd-886bf059d720"
-version = "1.4.1"
+version = "1.4.2"
 
 [[deps.PowerFlowData]]
-deps = ["DocStringExtensions", "InlineStrings", "Parsers", "PrettyTables", "Tables"]
+deps = ["DataFrames", "DocStringExtensions", "InlineStrings", "Parsers", "PrettyTables", "Tables"]
 path = ".."
 uuid = "dd99e9e3-7471-40fc-b48d-a10501125371"
-version = "1.4.0"
+version = "1.4.2"
 
 [[deps.PrettyTables]]
 deps = ["Crayons", "Formatting", "Markdown", "Reexport", "Tables"]

docs/Project.toml

@@ -2,3 +2,4 @@
 DataFrames = "a93c6f00-e57d-5684-b7b6-d8193f3e46c0"
 Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
 PowerFlowData = "dd99e9e3-7471-40fc-b48d-a10501125371"
+Tables = "bd369af6-aec1-5ad0-b16a-f7cc5008161c"

docs/make.jl

@@ -1,5 +1,6 @@
 using PowerFlowData
 using Documenter
+using Tables
 
 DocMeta.setdocmeta!(PowerFlowData, :DocTestSetup, :(using PowerFlowData); recursive=true)
 

docs/src/index.md

@@ -34,7 +34,7 @@ Comma delimited files `delim=','` and space delimited files `delim=' '` are curr
 Usually your data will be in a file, and you'd read it with `parse_network("file.raw")`,
 but here we'll pass in the data directly, to show how it matches to the output:
 
-```@repl
+```@repl example1
 using PowerFlowData, DataFrames
 data = IOBuffer("""
     0,   100.00          / PSS/E-30.3    WED, SEP 15 2021  21:04
@@ -49,3 +49,12 @@ network = parse_network(data; v=30);
 NamedTuple(network.caseid)  # Case Identification data is a single row.
 DataFrame(network.buses)    # Bus data, and all other data, is a table.
 ```
+
+For working with the tabular data within a [`Network`](@ref) directly you can use Tables.jl.
+For example, to iterate the [`Buses`](@ref):
+```@repl example1
+using Tables
+for bus in Tables.rows(network.buses)
+    @show bus.name
+end
+```

src/types.jl

@@ -59,7 +59,7 @@ Tables.columnaccess(::Type{<:Records}) = true
 Tables.columns(x::Records) = x
 Tables.getcolumn(x::Records, i::Int) = getfield(x, i)
 Tables.columnnames(R::Type{<:Records}) = fieldnames(R)
-Tables.schema(x::R) where {R <: Records} = Tables.Schema(fieldnames(R), fieldtypes(R))
+Tables.schema(x::R) where {R <: Records} = Tables.Schema(fieldnames(R), map(eltype, fieldtypes(R)))
 Tables.rowcount(x::Records) = length(x)  # faster than going via `columnnames`
 Base.length(x::Records) = length(getfield(x, 1)::Vector)
 Base.size(x::R) where {R <: Records} = (length(x), fieldcount(R))
@@ -1247,7 +1247,7 @@ end
 
 function Tables.schema(x::R) where {R <: Transformers}
     cols = Tables.columnnames(x)
-    typs = fieldtype.(R, cols)
+    typs = eltype.(fieldtype.(R, cols))
     return Tables.Schema(cols, typs)
 end
 

test/runtests.jl

@@ -34,6 +34,10 @@ using Test
         @test length(recs) == 3
         @test size(recs) == (3, 2)
 
+        @test Tables.rowtable(recs)[1] == (x1=1, yy=3.14)
+        @test NamedTuple(first(Tables.rows(recs))) == (x1=1, yy=3.14)
+        @test first(Tables.namedtupleiterator(recs)) == (x1=1, yy=3.14)
+
         df = DataFrame(recs)
         @test df isa DataFrame
         @test size(df) == (3, 2)
@@ -505,6 +509,16 @@ using Test
         @test length(qz.zones) == 2
     end
 
+    @testset "`Tables.namedtupleiterator(::Records)`" begin
+        # https://github.com/nickrobinson251/PowerFlowData.jl/issues/76
+        net = parse_network("testfiles/synthetic_data_v30.raw")
+        buses = net.buses
+        @test first(Tables.namedtupleiterator(buses)).i == 111
+        # Transformers has own `Tables.schema` definition so needs testing specifically.
+        transformers = net.transformers
+        @test first(Tables.namedtupleiterator(transformers)).i == 112
+    end
+
     @testset "empty network" begin
         empty_net = Network(version=30)
         @test isempty(empty_net)