From 7cb368965b313a0b8889621d8c17aa3b404ae419 Mon Sep 17 00:00:00 2001
From: Sascha Timme <sascha.timme@gmail.com>
Date: Fri, 28 Jun 2019 16:07:44 +0200
Subject: [PATCH] Better error messages

---
 Project.toml             |  5 +++--
 src/MixedSubdivisions.jl | 44 +++++++++++++++++++++++++++-------------
 test/runtests.jl         | 14 ++++++++++++-
 3 files changed, 46 insertions(+), 17 deletions(-)

diff --git a/Project.toml b/Project.toml
index 8f590d0..af9fd4d 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "MixedSubdivisions"
 uuid = "291d046c-3347-11e9-1e74-c3d251d406c6"
 authors = ["Sascha Timme <sascha.timme@gmail.com>"]
-version = "0.3.1"
+version = "0.3.2"
 
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
@@ -15,8 +15,9 @@ ProgressMeter = "^0.8, ^0.9, ^1.0"
 StaticArrays = "^0.9, ^0.10, ^0.11"
 
 [extras]
+MultivariatePolynomials = "102ac46a-7ee4-5c85-9060-abc95bfdeaa3"
 PolynomialTestSystems = "4c526841-e1e8-562c-bfa9-9f39d642e243"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["PolynomialTestSystems", "Test"]
+test = ["MultivariatePolynomials", "PolynomialTestSystems", "Test"]
diff --git a/src/MixedSubdivisions.jl b/src/MixedSubdivisions.jl
index 5a5ddec..ffef80b 100644
--- a/src/MixedSubdivisions.jl
+++ b/src/MixedSubdivisions.jl
@@ -1207,6 +1207,7 @@ Base.show(io::IO, MVC::MixedVolumeCounter) = print(io, "MixedVolume: $(MVC.volum
 
 traverser(Aᵢ::Matrix...; kwargs...) = traverser(Aᵢ; kwargs...)
 function traverser(As::Vector{<:Matrix}; algorithm=:regeneration)
+    length(As) == size(As[1], 1) || throw(ArgumentError("Number of supports and number of variables doesn't match."))
     if algorithm == :regeneration
         RegenerationTraverser(As)
     elseif algorithm == :total_degree
@@ -1241,19 +1242,27 @@ There are two possible values for `algorithm`:
 * `:regeneration`: Use the tropical regeneration algorithm described in Section 7.2
 """
 function mixed_volume(args...; show_progress=true, kwargs...)
-    T = traverser(args...; kwargs...)
-    mv = 0
-    complete = next_cell!(T)
-    if show_progress
-        p = ProgressMeter.ProgressUnknown("Mixed volume: ")
-    end
-    while !complete
-        mv += mixed_cell(T).volume
-        show_progress && ProgressMeter.update!(p, mv)
+    try
+        T = traverser(args...; kwargs...)
+        mv = 0
         complete = next_cell!(T)
+        if show_progress
+            p = ProgressMeter.ProgressUnknown("Mixed volume: ")
+        end
+        while !complete
+            mv += mixed_cell(T).volume
+            show_progress && ProgressMeter.update!(p, mv)
+            complete = next_cell!(T)
+        end
+        show_progress && ProgressMeter.finish!(p)
+        mv
+    catch e
+        if isa(e, InexactError)
+            throw(OverflowError("Mixed volume cannot since an integer overflow occured."))
+        else
+            rethrow(e)
+        end
     end
-    show_progress && ProgressMeter.finish!(p)
-    mv
 end
 
 """
@@ -1497,8 +1506,15 @@ induced by a sligtly perturbated lifting are computed.
 The mixed cells are stored as a [`MixedCell`](@ref).
 """
 function mixed_cells(support::Vector{<:Matrix}, lifting::Vector{<:Vector})
-    iter = MixedCellIterator(support, lifting)
-    [copy(c) for c in iter]
+    try
+        return [copy(c) for c in MixedCellIterator(support, lifting)]
+    catch e
+        if isa(e, InexactError)
+            throw(OverflowError("Mixed cells cannot be computed for this lift since an integer overflow occured."))
+        else
+            rethrow(e)
+        end
+    end
 end
 
 @inline function shift_indices!(ind::Vector{<:NTuple{2, <:Integer}}, m)
@@ -1560,7 +1576,7 @@ function fine_mixed_cells(support::Vector{<:Matrix}, lifting_sampler=gaussian_li
             end
         end
     catch e
-        if isa(e, InexactError) || isa(e, SingularException)
+        if isa(e, InexactError) || isa(e, LinearAlgebra.SingularException)
             return nothing
         else
             rethrow(e)
diff --git a/test/runtests.jl b/test/runtests.jl
index 375ec65..658c9e0 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1,6 +1,8 @@
 using MixedSubdivisions
 const MS = MixedSubdivisions
-import PolynomialTestSystems: equations, cyclic, ipp2
+import MultivariatePolynomials
+const MP = MultivariatePolynomials
+import PolynomialTestSystems: equations, cyclic, ipp2, cyclooctane
 using Test
 
 @testset "MixedSubdivisions" begin
@@ -102,4 +104,14 @@ using Test
 		@test sum(c -> c.volume, cells) == 924
 		@test lift isa Vector{Vector{Int32}}
 	end
+
+	@testset "Overflow error messages" begin
+		f = equations(cyclooctane())
+		@test_throws ArgumentError MS.mixed_volume(f)
+		F = [f; randn(2, 18) * [MP.variables(f);1]]
+		A = support(F)
+		lifting = map(Ai -> MS.gaussian_lifting_sampler(size(Ai,2)), A)
+		@test_throws OverflowError mixed_cells(A, lifting)
+		@test fine_mixed_cells(F) === nothing
+	end
 end