Any way to add outer while loops programmatically?

New to Julia
6

Full code below working nicely now for any number of knots with @hendri54’s method:

using ElasticArrays
# Computes all possible knot locations on a dataset with `il` number of points, for a minimum segment length of `ilsegmin` and `nknots` number of knots.
function allknots(il::Int, ilsegmin::Int, nknots::Int)

    # Initialize first knot combination
    knots = ElasticArray{Int}(undef, nknots, 1) # Create data storage structure for knots
    j = 1 # Possible knot location counter
    knots[1] = 1
    for n = 2:nknots - 1
        knots[n] = knots[n - 1] + ilsegmin - 1
    end
    knots[nknots] = il

    # Ensure first knot combination is possible
    if (nknots < 2) || (knots[nknots] - knots[nknots - 1] < ilsegmin)
        println("No possible knots with the given parameters.")
        return knots = ElasticArray{Int}(undef, nknots, 0)
    end
    
    # Determine all remaining knot combinations
    function incrementknot(il::Int, ilsegmin::Int, nknots::Int, k::Int=nknots - 2)

        while knots[nknots - k, j] < il - k * ilsegmin + k # While current knot not yet at maximum location
            if k > 1
                incrementknot(il, ilsegmin, nknots, k - 1) # Call function recursively to obtain inner while loops
            elseif k < 1
                throw(ArgumentError("k must be a counting number"))
            end
            j += 1                                         # Increment possible knot counter
            append!(knots, knots[:, j - 1])                # Create new knot combination same as last knot combination except...
            knots[nknots - k, j] += 1                      #  increment current knot and
            for kk = k - 1:-1:1                            #  reset all downstream knots
                knots[nknots - kk, j] = knots[nknots - (kk + 1), j] + ilsegmin - 1
            end
        end
        return knots
    end

    incrementknot(il, ilsegmin, nknots)
    return knots
end

# Test
for n = 1:7
    display(allknots(12, 3, n))
end