Add least_dims

src/utils.jl

@@ -4,3 +4,14 @@
 Safely divide `x` by `y`. If `y` is zero, return `x` directly.
 """
 safe_div(x, y) = ifelse(iszero(y), x, x/y)
+
+"""
+    least_dims(idxs)
+
+Compute the least dimensions, of which array can be accessed by the indecies `idxs`.
+"""
+least_dims(idxs::AbstractArray{<:Integer}) = (maximum(idxs), )
+
+function least_dims(idxs::AbstractArray{<:Tuple})
+    Tuple(maximum(xs) for xs in zip(idxs...))
+end

test/utils.jl

@@ -0,0 +1,9 @@
+@testset "least_dims" begin
+    ind1 = [1,2,3,4,5,6]
+    @test NNlib.least_dims(ind1) == (6,)
+    ind2 = [(3,4,5), (1,2,3), (2,3,9)]
+    @test NNlib.least_dims(ind2) == (3,4,9)
+    ind3 = [(3,4,5) (1,2,3) (2,3,9);
+            (4,6,2) (5,3,2) (4,4,4)]
+    @test NNlib.least_dims(ind3) == (5,6,9)
+end