[Swift-user] tutorial/understanding issue 7

[Daniel S. Katz]

Thanks.  Can this be added to the Swift list of bugs as a low priority issue?

Dan


On Oct 14, 2010, at 3:35 PM, Mihael Hategan wrote:

> Inline
> 
> On Thu, 2010-10-14 at 12:08 -0500, Daniel S. Katz wrote:
> 
>> Continuing my journey through the Swift tutorial
>> (http://www.ci.uchicago.edu/swift/guides/tutorial.php), though the
>> previous 6 messages are waiting for approval, as I was not a member of
>> the swift-users list when I sent them...
>> 
>> 
>> In section 3.5, why can't I do this:
>> 
>> 
>> 
>> 
>> type messagefile;
>> 
>> 
>> app (messagefile t) greeting (string s[]) {
>>    echo s[0] s[1] s[2] stdout=@filename(t);
>> }
>> 
>> 
>> messagefile outfile <"q5out.txt">;
>> 
>> 
>> #string words[] = ["how","are","you"];
>> string words[];
>> words[0] = "how;
>> words[1] = "are";
>> words[2] = "you";
>> 
>> 
>> outfile = greeting(words);
>> 
> There is no theoretical reason why you shouldn't be able to do so. It
> follows that we are talking about a bug. It was likely not addressed (or
> reported) because there is a way to deal with the situation.
>> 
>> 
>> is the issue that swift doesn't know how large to make words[]?
>> 
> Arrays are dynamic, so not quite. 
>> 
>> I also tried:
>> 
>> 
>> string words[3];
>> 
>> 
>> but this also didn't work.
>> 
> A good point. There is, when iterating over an array, a distinction
> between an array whose size you know and one whose size is not known
> statically. The above type of declaration could be used to provide that
> information, and I think it should be added to swift (if missing).
>> 
>> Do strings need to be assigned when they are declared?  Is this a
>> general rule for Swift variables?
>> 
> No in theory. Variables need to eventually be assigned, otherwise they
> are considered "input" variables. But that does not apply to primitives.
> So in the case of strings your code should work.
> 
> Mihael
> 
> 

-- 
Daniel S. Katz
University of Chicago
(773) 834-7186 (voice)
(773) 834-3700 (fax)
d.katz at ieee.org or dsk at ci.uchicago.edu
http://www.ci.uchicago.edu/~dsk/