Comments on: goto statement considered

By: Jeff

Jeff — Sat, 21 Nov 2009 00:23:07 +0000

The number of columns in the string may not change and the increment operator would add a character to the beginning of the string. Also, the range operator does not appear to do what I need it to. I initially used that, but it cannot handle punctuation, which this must handle.

By: RJ

RJ — Fri, 20 Nov 2009 07:41:59 +0000

If I understand your problem correctly, doesn’t this easily solve it without a goto statement:

def increment(string, by):
bytes = deque()
for c in string:
byte = ord(c)
if ord(“0″) <= byte <= ord("9"):
byte -= ord("0")
byte = (byte + by) % 9
byte += ord("0")
elif ord("a") <= byte <= ord("z"):
byte -= ord("a")
byte = (byte + by) % 25
byte += ord("a")
elif ord("A") <= byte <= ord("Z"):
byte -= ord("A")
byte = (byte + by) % 25
byte += ord("A")
bytes.append(byte)
return "".join(bytes)

Yes, it's in Python, but easily convertible to Perl and you can extract the inner part of the for loop into a function since you want to transform it char by char.

By: stewart

stewart — Fri, 20 Nov 2009 05:33:12 +0000

rather let the functional programming paradigm of programming structure your goto statement

By: Rudolf O.

Rudolf O. — Fri, 20 Nov 2009 05:32:39 +0000

Post your code!

By: Phil

Phil — Fri, 20 Nov 2009 04:20:55 +0000

Surely, you've seen Knuth's take on the issue: Structured Programming with Goto. It's very insightful reading on this topic, has some great humor, and presages a lot of great ideas seen in later development.

By: Nicolas Dumazet

Nicolas Dumazet — Fri, 20 Nov 2009 04:17:55 +0000

This post obviously lacks code examples. Show us.

By: JadeNB

JadeNB — Fri, 20 Nov 2009 03:53:55 +0000

Setting aside the main point of your post --you mention Perl, so is it reasonable to assume that you were coding in Perl? If so, note that the ++ operator already behaves this way—see http://perldoc.perl.org/perlop.html#Auto-increment-and-Auto-decrement—and .. ranges behave as you'd hope.

By: Rzeźnik

Rzeźnik — Fri, 20 Nov 2009 02:55:29 +0000

Right. I have recently finished implementation of coroutines in Java (http://code.google.com/p/coroutines – if you care), and I must admit that I would not have gone anywhere without goto (although bytecode one). That’s at the heart of resuming a coroutine execution. I started to think that goto has its place where it cannot be abused. But I also agree that it must be constrained so that careless programmers do not see it very often :-)

By: ilowry

ilowry — Thu, 19 Nov 2009 16:29:06 +0000

Agreed! GOTO rocks. If constrained.
My usual heurisitics for gotos in C/C++ – no more then 1-3 labels and forward non-crossing jumps only.