fixed some things, got more segfaults

src/acsets/ACSetInterface.jl

@@ -70,14 +70,17 @@ function view_or_slice end
 @inline view_or_slice(x::AbstractVector, ::Colon) = x
 @inline Base.@propagate_inbounds view_or_slice(x::AbstractVector, i) = @view x[i]
 
+collect_or_id(i) = i
+collect_or_id(xs::AbstractVector{T}) where {T} = T[xs...]
+
 function subpart(acs, part, names::AbstractVector{Symbol})
   foldl(names, init=part) do part, name
-    subpart(acs, part, name)
+    collect_or_id(subpart(acs, part, name))
   end
 end
 
 subpart(acs, names::AbstractVector{Symbol}) =
-  subpart(acs, subpart(acs, names[1]), names[2:end])
+  subpart(acs, Int[subpart(acs, names[1])...], names[2:end])
 
 Base.getindex(acs::ACSet, part, name) = subpart(acs, part, name)
 Base.getindex(acs::ACSet, name) = subpart(acs, name)

src/acsets/Mappings.jl

@@ -29,6 +29,9 @@ const VecMapStorage{T} = Union{AbstractPartialVector{T}, AbstractVector{T}}
 
 struct VecMap{T, V} <: Mapping{Int, T}
   v::V
+  function VecMap{T,V}(v::V) where {T,V}
+    new{T,V}(v)
+  end
 end
 
 VecMap{T,V}() where {T,V} = VecMap{T,V}(V())
@@ -65,7 +68,7 @@ function extend!(v::AbstractVector, n::Int)
   append!(v, Iterators.map(_ -> nothing, Base.OneTo(k)))
 end
 
-@propagate_inbounds function Base.getindex(m::VecMap, i::Int)
+@propagate_inbounds function _get_or_nothing(m::VecMap, i::Int)
   @boundscheck begin
     if i > length(m.v)
       return nothing
@@ -74,8 +77,17 @@ end
   @inbounds m.v[i]
 end
 
+@propagate_inbounds function Base.getindex(m::VecMap{T}, i::Int) where {T}
+  x = _get_or_nothing(m, i)
+  if isnothing(x)
+    throw(BoundsError(m, i))
+  else
+    x::T
+  end
+end
+
 function Base.get(m::VecMap, i::Int, def)
-  v = m[i]
+  v = _get_or_nothing(m, i)
   if isnothing(v)
     def
   else
@@ -84,7 +96,7 @@ function Base.get(m::VecMap, i::Int, def)
 end
 
 function Base.get(f::Any, m::VecMap, i::Int)
-  v = m[i]
+  v = _get_or_nothing(m, i)
   if isnothing(v)
     f()
   else
@@ -111,7 +123,7 @@ end
 end
 
 function Base.get!(m::VecMap{T}, i::Int, def::T) where {T}
-  v = m[i]
+  v = _get_or_nothing(m, i)
   if isnothing(v)
     m[i] = def
   else
@@ -120,7 +132,7 @@ function Base.get!(m::VecMap{T}, i::Int, def::T) where {T}
 end
 
 function Base.get!(f::Union{Function, Type}, m::VecMap{T}, i::Int) where {T}
-  v = m[i]
+  v = _get_or_nothing(m, i)
   if isnothing(v)
     m[i] = f()
   else
@@ -129,7 +141,7 @@ function Base.get!(f::Union{Function, Type}, m::VecMap{T}, i::Int) where {T}
 end
 
 Base.haskey(m::VecMap, i::Int) =
-  i ∈ 1:length(m.v) && !isnothing(@inbounds m[i])
+  !isnothing(_get_or_nothing(m, i))
 
 Base.keys(m::VecMap) = Iterators.filter(i -> haskey(m, i), 1:length(m.v))
 

src/acsets/PreimageCaches.jl

@@ -104,7 +104,7 @@ end
 Base.copy(pc::TrivialCache) = pc
 
 function preimage(dom, m::Mapping{S,T}, ::TrivialCache{S,T}, y) where {S,T}
-  [x for x in dom if m[x] == y]
+  [x for x in dom if get(m, x, nothing) == y]
 end
 
 function preimage_multi(dom, m::Mapping{S,T}, pc::TrivialCache{S,T}, ys) where {S,T}
@@ -144,8 +144,8 @@ function preimage(
   values(get(() -> Preimage(), pc.preimages, y))
 end
 
-function preimage_multi(dom, m::Mapping, pc::StoredPreimageCache, ys)
-  Vector{Vector{Any}}(collect(Iterators.map(values, view_with_default(pc.preimages, ys, DefaultEmpty))))
+function preimage_multi(dom, m::Mapping, pc::StoredPreimageCache{S,T,Preimage}, ys) where {S,T,Preimage}
+  Vector{Vector{S}}(collect(Iterators.map(values, view_with_default(pc.preimages, ys, DefaultEmpty{Preimage}))))
 end
 
 # Assumes that i.preimages[y] is already stored

src/categorical_algebra/FinSets.jl

@@ -1109,7 +1109,7 @@ function colimit(F::Functor{<:FinCat{Int},<:TypeCat{<:FinSet{Int}}})
   # Uses the general formula for colimits in Set (Leinster, 2014, Basic Category
   # Theory, Example 5.2.16).
   J = dom(F)
-  coprod = coproduct(map(x -> ob_map(F, x), ob_generators(J)))
+  coprod = coproduct(map(x -> ob_map(F, x)::FinSet{Int,Int}, ob_generators(J)))
   n, ιs = length(ob(coprod)), legs(coprod)
   sets = IntDisjointSets(n)
   for f in hom_generators(J)