empty sparse polynomial

Change firstindex and lastindex for sparse polynomials to span
the entire range of indices

Author: jishnub

src/polynomials/SparsePolynomial.jl

@@ -127,11 +127,6 @@ function Base.setindex!(p::SparsePolynomial, value::Number, idx::Int)
     return p
 end
 
-
-Base.firstindex(p::SparsePolynomial) = sort!(collect(keys(p.coeffs)), by=x->x[1])[1]
-Base.lastindex(p::SparsePolynomial) = sort!(collect(keys(p.coeffs)), by=x->x[1])[end]
-Base.eachindex(p::SparsePolynomial) = sort!(collect(keys(p.coeffs)), by=x->x[1])
-
 # pairs iterates only over non-zero
 # inherits order for underlying dictionary
 function Base.iterate(v::PolynomialKeys{SparsePolynomial{T,X}}, state...) where {T,X}

test/ChebyshevT.jl

@@ -1,19 +1,22 @@
-@testset "Construction" for coeff in [
-    Int64[1, 1, 1, 1],
-    Float32[1, -4, 2],
-    ComplexF64[1 - 1im, 2 + 3im],
-    [3 // 4, -2 // 1, 1 // 1]
-]
-    p = ChebyshevT(coeff)
-    @test p.coeffs == coeff
-    @test coeffs(p) == coeff
-    @test degree(p) == length(coeff) - 1
-    @test Polynomials.indeterminate(p) == :x
-    @test length(p) == length(coeff)
-    @test size(p) == size(coeff)
-    @test size(p, 1) == size(coeff, 1)
-    @test typeof(p).parameters[1] == eltype(coeff)
-    @test eltype(p) == eltype(coeff)
+@testset "Construction" begin
+    @testset for coeff in Any[
+        Int64[1, 1, 1, 1],
+        Float32[1, -4, 2],
+        ComplexF64[1 - 1im, 2 + 3im],
+        [3 // 4, -2 // 1, 1 // 1]
+    ]
+
+        p = ChebyshevT(coeff)
+        @test p.coeffs == coeff
+        @test coeffs(p) == coeff
+        @test degree(p) == length(coeff) - 1
+        @test Polynomials.indeterminate(p) == :x
+        @test length(p) == length(coeff)
+        @test size(p) == size(coeff)
+        @test size(p, 1) == size(coeff, 1)
+        @test typeof(p).parameters[1] == eltype(coeff)
+        @test eltype(p) == eltype(coeff)
+    end
 end
 
 @testset "Other Construction" begin

test/StandardBasis.jl

@@ -28,36 +28,39 @@ Ps = (ImmutablePolynomial, Polynomial, SparsePolynomial, LaurentPolynomial, Fact
 isimmutable(p::P) where {P} = P <: ImmutablePolynomial
 isimmutable(::Type{<:ImmutablePolynomial}) = true
 
-@testset "Construction" for coeff in [
-                                      Int64[1, 1, 1, 1],
-                                      Float32[1, -4, 2],
-                                      ComplexF64[1 - 1im, 2 + 3im],
-                                      [3 // 4, -2 // 1, 1 // 1]
-                                     ]
+@testset "Construction" begin
+    @testset for coeff in Any[
+          Int64[1, 1, 1, 1],
+          Float32[1, -4, 2],
+          ComplexF64[1 - 1im, 2 + 3im],
+          [3 // 4, -2 // 1, 1 // 1]
+         ]
+
+        @testset for P in Ps
+            p = P(coeff)
+            @test coeffs(p) ==ᵗ⁰ coeff
+            @test degree(p) == length(coeff) - 1
+            @test indeterminate(p) == :x
+            P == Polynomial && @test length(p) == length(coeff)
+            P == Polynomial && @test size(p) == size(coeff)
+            P == Polynomial && @test size(p, 1) == size(coeff, 1)
+            P == Polynomial && @test typeof(p).parameters[1] == eltype(coeff)
+            if P != FactoredPolynomial
+                @test eltype(p) == eltype(coeff)
+            end
+            @test all([-200, -0.3, 1, 48.2] .∈ Polynomials.domain(p))
 
-    for P in Ps
-        p = P(coeff)
-        @test coeffs(p) ==ᵗ⁰ coeff
-        @test degree(p) == length(coeff) - 1
-        @test indeterminate(p) == :x
-        P == Polynomial && @test length(p) == length(coeff)
-        P == Polynomial && @test size(p) == size(coeff)
-        P == Polynomial && @test size(p, 1) == size(coeff, 1)
-        P == Polynomial && @test typeof(p).parameters[1] == eltype(coeff)
-        @test eltype(p) == eltype(coeff)
-        @test all([-200, -0.3, 1, 48.2] .∈ Polynomials.domain(p))
-
-        ## issue #316
-        @test_throws InexactError P{Int,:x}([1+im, 1])
-        @test_throws InexactError P{Int}([1+im, 1], :x)
-        @test_throws InexactError P{Int,:x}(1+im)
-        @test_throws InexactError P{Int}(1+im)
-
-        ## issue #395
-        v = [1,2,3]
-        @test P(v) == P(v,:x) == P(v,'x') == P(v,"x") == P(v, Polynomials.Var(:x))
-    end
+            ## issue #316
+            @test_throws InexactError P{Int,:x}([1+im, 1])
+            @test_throws InexactError P{Int}([1+im, 1], :x)
+            @test_throws InexactError P{Int,:x}(1+im)
+            @test_throws InexactError P{Int}(1+im)
 
+            ## issue #395
+            v = [1,2,3]
+            @test P(v) == P(v,:x) == P(v,'x') == P(v,"x") == P(v, Polynomials.Var(:x))
+        end
+    end
 end
 
 @testset "Mapdomain" begin
@@ -1493,3 +1496,13 @@ end
     @test c == MA.operate(*, A, b)
     @test 0 == @allocated MA.buffered_operate!(buffer, MA.add_mul, c, A, b)
 end
+
+@testset "empty SparsePolynomial" begin
+    p = SparsePolynomial(Float64[0])
+    @test eltype(p) == Float64
+    @test eltype(keys(p)) == Int
+    @test eltype(values(p)) == Float64
+    @test collect(p) == Float64[]
+    @test collect(keys(p)) == Int[]
+    @test collect(values(p)) == Float64[]
+end