覆蓋部分字符串

Question

是否有一種簡單的方法來覆蓋字符串，如下所示，或類似的東西？

s = "123456" 
r1 = "abc" 
s.loverwrite(r1) # => "abc456" 
s.coverwrite(r1) # => "12abc6" (or "1abc56") 
s.roverwrite(r1) # => "123abc" 

r2 = "abcdefghi" 
s.loverwrite(r2) # => "abcdef" 
s.coverwrite(r2) # => "bcdefg" (or "cdefgh") 
s.roverwrite(r2) # => "defghi" 

Answer 1

很容易與[]=：

class String 
    def loverwrite(s) 
    dup.tap{|result| result[0, s.length] = s[0, length]} 
    end 
end