Hendrik van Rooyen wrote:
> "Donn Cave" <[EMAIL PROTECTED]> wrote:
>
>> In its day, goto was of course very well loved.
>
> Does anybody know for sure if it is in fact possible to
> design a language completely free from conditional jumps?
>
> At the lower level, I don't think you can get away with
> conditional calls - hence the "jumps with dark glasses",
> continue and break.
>
> I don't think you can get that functionality in another way.
>
> Think of solving the problem of reading a text file to find
> the first occurrence of some given string - can it be done
> without either break or continue? (given that you have to
> stop when you have found it)
>
Pascal has no break, continue or return. Eiffel doesn't even have a
goto. In such imperative languages boolean variables are used a lot.
from StringIO import StringIO
lines = StringIO("one\ntwo\nthree\nfour\n")
line_number = 0
eof = False
found = False
while not (eof or found):
line = lines.readline()
eof = line == ""
found = line == "three\n"
if not found:
line_number += 1
if found:
print "Found at", line_number
else:
print "Not found"
# prints "Found at 2"
---
Lenard Lindstrom
<[EMAIL PROTECTED]>
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