5 ms·

I don't write a lot of while loops so this is just a bit unfamiliar to me, but I'm not really understanding how this isn't the same as `do{block}while(condition

• TrianguloY 2y ago
  Think of a producer (a method that returns data each time you request one, like reading a file line by line or extracting the top of a queue for example) that you need to parse and process until you find a special element that means "stop". Something like do{ raw_data=produce.get() data=parse(raw_data) }while(data!=STOP){ process(data) } I'm aware this example can be trivially replaced with a while(data=parse(producer.get())){process(data)} but you are forced to have a method, and if you need both the raw and parsed data at the same time, either you mix them into a wrapper or you need to somehow transfer two variables at the same time from the parse>condition>process A do-while here also has the same issue, but in this case after you check the condition you can't do any processing afterwards (unless you move the check and process into a single check_and_process method...which you can totally do but again the idea is to not require it)
• bandie91 2y ago
  i often want to write: do { offset = tell(filehandle) } while(line = readline(filehandle)) { print "line starts at offset: ", offset }