Feature #15496

Updated by macdevign (Macdevign mac) over 2 years ago

I could not find the a simple String api to extract the string between two string, and I notice that many face the same issue and endup rolling their own solutions (eg  

 Given that string "between" extraction is such a common operation, will adding a focused and simplified String method    make coding pleasant ? 

 This is my solution but probably someone can provide better and efficient implementation. 

   # self: String instance,  
   # from: String -> first 'from' String   
   # to: String ->    first 'to' String found after 'from' 
   # ignore_case: Boolean -> to indicate case-sensitive search 
   # from_index: Integer -> Position of 'From' string to start search from 
   # return string between from and to, which exclude the argument, nil otherwise. 


   def between(from, to, ignore_case: false, from_index: 0) to) 
       str = self 
       str, from, to = str.downcase, from.downcase, to.downcase if ignore_case 

       from_idx = str.index(from, from_index)&.+(from.length) self.index(from)&.+(from.length) 
       if from_idx 
         to_idx = str.index(to, self.index(to, from_idx) 
         return str[from_idx...to_idx] self[from_idx...to_idx] if to_idx 

 Test case 

 "Hello world".between("ell", "ld") => "o wor" 
 "Testing 123".between("Te", "123") => "sting " 
 "Testing 123".between("te", "123") => nil  
 "Testing 123".between("te", "123", ignore_case: true) => "sting " 
 "Testing 123".between("te", "123", from_index: 3) => nil