From fcea952fdff99a21279e792b71d8be2cbc018977 Mon Sep 17 00:00:00 2001
From: Diego Javier Zea <diegozea@gmail.com>
Date: Tue, 25 May 2021 23:08:40 +0200
Subject: [PATCH] Fix from_table

---
 NEWS.md                   |  4 ++++
 Project.toml              |  2 +-
 README.md                 | 12 ++++++++++--
 src/pairwiselistmatrix.jl | 30 +++++++++++++++++-------------
 test/runtests.jl          |  9 +++++++++
 5 files changed, 41 insertions(+), 16 deletions(-)

diff --git a/NEWS.md b/NEWS.md
index 582c6f7..e1da03b 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,9 @@
 ## PairwiseListMatrices.jl Release Notes
 
+## Changes from v0.10 to v0.11
+
+Fix bug in `from_table`.
+
 ## Changes from v0.9 to v0.10
 
 * Add the `@iterateupper,`, `@iteratelist` and `@iteratediag` macros back again 
diff --git a/Project.toml b/Project.toml
index 16568ae..de264e6 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "PairwiseListMatrices"
 uuid = "f9da4da7-9382-5435-b973-175f5d8dfb32"
-version = "0.10.0"
+version = "0.11.0"
 
 [deps]
 DelimitedFiles = "8bb1440f-4735-579b-a4ab-409b98df4dab"
diff --git a/README.md b/README.md
index 39d9bb4..76e0614 100644
--- a/README.md
+++ b/README.md
@@ -68,8 +68,8 @@ a     │ 0  1  2
 b     │ 1  0  3
 c     │ 2  3  0
 
-julia> to_table(nplm)
-6×3 Array{Any,2}:
+julia> table = to_table(nplm)
+6×3 Matrix{Any}:
  "a"  "a"  0
  "a"  "b"  1
  "a"  "c"  2
@@ -77,4 +77,12 @@ julia> to_table(nplm)
  "b"  "c"  3
  "c"  "c"  0
 
+julia> from_table(table, true)
+3×3 Named PairwiseListMatrix{Any, true, Vector{Any}}
+A ╲ B │ a  b  c
+──────┼────────
+a     │ 0  1  2
+b     │ 1  0  3
+c     │ 2  3  0
+
 ```
diff --git a/src/pairwiselistmatrix.jl b/src/pairwiselistmatrix.jl
index 763d067..8e6c4ab 100644
--- a/src/pairwiselistmatrix.jl
+++ b/src/pairwiselistmatrix.jl
@@ -107,20 +107,24 @@ end
 # Empties
 # -------
 
-function _diagonal_value(diagonal::Bool, ::Type{T}) where T
-    if !diagonal
-        if hasmethod(zero, (T,))
-            return zero(T)
-        elseif T <: Union{Missing, Int}
-            return missing
+function _diagonal_value(::Type{T}) where T
+    if hasmethod(zero, (T,))
+        return zero(T)
+    else
+        if T isa Union
+            T_types = Base.uniontypes(T)
+            if Missing ∈ T_types
+                return missing
+            end
+            if Nothing ∈ T_types
+                return nothing
+            end
         elseif T === Any
             return nothing
-        else
-            throw(ErrorException(
-            "Please use the last argument to fill the diagonal. It should be of type $T."))
         end
     end
-    Array{T}(undef, 1)[1]
+    throw(ErrorException(
+       "Please use the last argument to fill the diagonal. It should be of type $T."))
 end
 
 
@@ -139,7 +143,7 @@ PairwiseListMatrix(Int, 3, true)
 function PairwiseListMatrix(::Type{T},
                            nelements::Int,
                            diagonal::Bool = false,
-                           diagonalvalue::T = _diagonal_value(diagonal, T)) where T
+                           diagonalvalue::T = _diagonal_value(T)) where T
     if diagonal
         return PairwiseListMatrix{T, true, Vector{T}}(
             Array{T}(undef, lengthlist(nelements, Val{true})),
@@ -283,7 +287,7 @@ instead of being on the list. The `diag` vector can be filled with the optional
 """
 function PairwiseListMatrix(list::AbstractVector{T},
                            diagonal::Bool = false,
-                           diagonalvalue::T = _diagonal_value(diagonal, T)) where T
+                           diagonalvalue::T = _diagonal_value(T)) where T
     VT = typeof(list)
     if diagonal
         nelements = _nelements_with_diagonal(length(list))
@@ -1170,7 +1174,7 @@ function from_table(table,
     @assert size(table,2) >= 3
     values = table[:,valuecol]
     if diagonalvalue == :default
-        diagonalvalue = _diagonal_value(diagonal, eltype(values))
+        diagonalvalue = _diagonal_value(eltype(values))
     end
     plm  = PairwiseListMatrix(values, diagonal, diagonalvalue)
     nplm = NamedArray(plm)
diff --git a/test/runtests.jl b/test/runtests.jl
index ca6516b..53a1197 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -582,6 +582,15 @@ end
 
         @test to_table(list) == to_table(list_diag)
         @test to_table(list, diagonal=false) == to_table(list_diag, diagonal=false)
+
+        @testset "README" begin
+            # using Any type instead of Int to allow @test
+            plm  = PairwiseListMatrix(Any[1,2,3], false)
+            nplm  = setlabels(plm, ["a","b","c"])
+            table = to_table(nplm)
+            new_nplm = from_table(table, true)
+            @test new_nplm == plm
+        end
     end
 
     @testset "DataFrames" begin