Support BitArrays

[matbesancon]

The issue came up when using JuMP with bitarrays, the top of the stack was:

ERROR: MethodError: no method matching similar_array_type(::Type{BitVector}, ::Type{JuMP.AffExpr})

Closest candidates are:
  similar_array_type(::Type{LinearAlgebra.Symmetric{T, MT}}, ::Type{S}) where {S, T, MT}
   @ MutableArithmetics ~/.julia/packages/MutableArithmetics/cnvbo/src/implementations/LinearAlgebra.jl:151
  similar_array_type(::Type{Array{T, N}}, ::Type{S}) where {S, T, N}
   @ MutableArithmetics ~/.julia/packages/MutableArithmetics/cnvbo/src/implementations/LinearAlgebra.jl:158
  similar_array_type(::Type{<:Union{LinearAlgebra.Adjoint{T, A}, LinearAlgebra.Transpose{T, A}}}, ::Type{S}) where {S, T, A}
   @ MutableArithmetics ~/.julia/packages/MutableArithmetics/cnvbo/src/implementations/LinearAlgebra.jl:442

from an expression:

    @constraint(m, sum(α[i] * vertices[i] for i in 1:nv) .== x)

with alpha a vector of variables and vertices a vector of BitVectors

[odow]

Do you have a reproducible example?

Did you mean @constraint(m, sum(α[i] .* vertices[i] for i in 1:nv) .== x)?

[matbesancon]

alpha[i] is a scalar variable, each vertices[i] is a BitVector.

I'll try to boil it down

[matbesancon]

vertices = [
       falses(4),
       trues(4),
]
m = Model()
n = length(vertices[1])
nv = length(vertices)
@variable(m, x[1:n])
@variable(m, α[1:nv] >= 0)
@constraint(m, sum(α[i] * vertices[i] for i in 1:nv) .== x)

[odow]

So this worked:

julia> using JuMP

julia> data = [falses(4), trues(4)]
2-element Vector{BitVector}:
 [0, 0, 0, 0]
 [1, 1, 1, 1]

julia> model = Model()
A JuMP Model
Feasibility problem with:
Variables: 0
Model mode: AUTOMATIC
CachingOptimizer state: NO_OPTIMIZER
Solver name: No optimizer attached.

julia> @variable(model, x[1:4])
4-element Vector{VariableRef}:
 x[1]
 x[2]
 x[3]
 x[4]

julia> @variable(model, y[1:2])
2-element Vector{VariableRef}:
 y[1]
 y[2]

julia> @constraint(model, sum(y[i] .* data[i] for i in 1:2) .== x)
4-element Vector{ConstraintRef{Model, MathOptInterface.ConstraintIndex{MathOptInterface.ScalarAffineFunction{Float64}, MathOptInterface.EqualTo{Float64}}, ScalarShape}}:
 -x[1] + y[2] = 0
 -x[2] + y[2] = 0
 -x[3] + y[2] = 0
 -x[4] + y[2] = 0

But the other error message is bad.

[odow]

julia> import MutableArithmetics as MA

julia> x = zeros(BigInt, 2)
2-element Vector{BigInt}:
 0
 0

julia> MA.operate!!(MA.add_mul, x, big(1), trues(2))
ERROR: MethodError: no method matching similar_array_type(::Type{BitVector}, ::Type{BigInt})

Closest candidates are:
  similar_array_type(::Type{LinearAlgebra.Symmetric{T, MT}}, ::Type{S}) where {S, T, MT}
   @ MutableArithmetics ~/.julia/dev/MutableArithmetics/src/implementations/LinearAlgebra.jl:151
  similar_array_type(::Type{Array{T, N}}, ::Type{S}) where {S, T, N}
   @ MutableArithmetics ~/.julia/dev/MutableArithmetics/src/implementations/LinearAlgebra.jl:158
  similar_array_type(::Type{<:Union{LinearAlgebra.Adjoint{T, A}, LinearAlgebra.Transpose{T, A}}}, ::Type{S}) where {S, T, A}
   @ MutableArithmetics ~/.julia/dev/MutableArithmetics/src/implementations/LinearAlgebra.jl:442
  ...

Stacktrace:
 [1] promote_operation(op::typeof(*), #unused#::Type{BigInt}, A::Type{BitVector})
   @ MutableArithmetics ~/.julia/dev/MutableArithmetics/src/implementations/LinearAlgebra.jl:173
 [2] promote_operation_fallback(op::typeof(MutableArithmetics.add_mul), #unused#::Type{Vector{BigInt}}, #unused#::Type{BigInt}, #unused#::Type{BitVector})
   @ MutableArithmetics ~/.julia/dev/MutableArithmetics/src/interface.jl:82
 [3] promote_operation(::typeof(MutableArithmetics.add_mul), ::Type, ::Type, ::Type)
   @ MutableArithmetics ~/.julia/dev/MutableArithmetics/src/interface.jl:113
 [4] mutability(::Type, ::Function, ::Type, ::Type, ::Type)
   @ MutableArithmetics ~/.julia/dev/MutableArithmetics/src/interface.jl:266
 [5] mutability(::Vector{BigInt}, ::Function, ::Vector{BigInt}, ::BigInt, ::BitVector)
   @ MutableArithmetics ~/.julia/dev/MutableArithmetics/src/interface.jl:274
 [6] operate!!(::typeof(MutableArithmetics.add_mul), ::Vector{BigInt}, ::BigInt, ::BitVector)
   @ MutableArithmetics ~/.julia/dev/MutableArithmetics/src/rewrite.jl:93
 [7] top-level scope
   @ REPL[8]:1