Fuzzy method calling

HAL.rb

module HAL
    module_function

    def calc_weight(index, length)
        distance = (length - 1.0 - index) / (length - 1.0)
        distance * distance * 0.5 + 1.0
    end

    def strings_distance(source, target, distance_limit)
        if source == target
            return 0
        end 
        m = source.size
        n = target.size
        if (m - n).abs > distance_limit
            return 100
        end
        inf = m + n
        h = Array.new(m + 2) { |i|
            a = Array.new(n + 2, 0)
            a[0] = inf 
            a[1] = i
            a
        }
        h1 = h[1]
        h0 = h[0]
        (0..n).each do |i|
            h1[i + 1] = i
            h0[i + 1] = inf
        end
        sd = {}
        (1..m).each do |i|
            db = 0
            hi = h[i]
            hi1 = h[i + 1]
            weight = calc_weight(i - 1, m)
            c1 = source[i - 1].downcase
            (1..n).each do |j|
                i1 = sd[target[j - 1]] || 0
                j1 = db
                c2 = target[j - 1]
                if c1 == c2.downcase
                    hi1[j + 1] = hi[j]
                    db = j
                else
                    hi1[j + 1] = [hi[j], hi1[j], hi[j + 1]].min + 1 * weight
                end
                hi1[j + 1] = [hi1[j + 1], h[i1][j1] + ((i - i1 - 1) + 1 + (j - j1 - 1)) * weight].min
            end 
            sd[source[i - 1]] = i
        end
        h[m + 1][n + 1]
    end
end

class Object
    def method_missing(name, *args)
        matched_method = []
        name = name.to_s
        public_methods.each { |method|
            score = HAL.strings_distance(name, method.to_s, 2)
            matched_method.push([score, method]) if score <= 2 
        }
        matched_method.sort! { |a, b|
            a[0] <=> b[0]
        }
        if matched_method.size > 0
            public_send(matched_method[0][1], *args)
        else
            raise NoMethodError, "undefined method `#{name}'"
        end
    end
end

test.rb

require "./HAL"

class Test
    def say_hello
        puts "hello"
    end
end

test = Test.new

test.say_helo
# > "hello"