bug: splatting with type is not matched

[Xiu-zhe (Roger) Luo]

MWE:

using MLStyle: @match
@match :(A[2, 4]) begin
    Expr(:ref, name::Symbol, size::Int...) => begin
        @show size
    end
end

[Taine Zhao]

The pattern should not be Expr(:ref, name::Symbol, size::Int...), think of how it gets constructed:

name = :A
size = [1, 2]
Expr(:ref, name::Symbol, size::Int...) 

ERROR: TypeError: in typeassert, expected Int64, got a value of type typeof(size)

As match is reversing construction, we can think about the construction firstly:

# construct
sz = [2, 4]
@assert Expr(:ref, name::Symbol, [e::Int for e in sz]...)  == :(A[2, 4])

# so the deconstruction is:

@match :(A[2, 4]) begin
       Expr(:ref, name::Symbol, [e::Int for e in size]...) => begin
            @show size
        end
end
# size = [2, 4]

P.S: do not use Int[e for e in size], because it is Vector{Any}:

julia> Expr(:ref, name::Symbol, [1, 2]...).args
3-element Vector{Any}:
  :A
 1
 2