[Swift-user] suggestion for program flow control

[Michael Wilde]

Can this technique be readily applied to a function that runs N app() 
functions in a foreach()?

(external o) doall(Collection c) {
	foreach i in c {
		x = someapp();
         }
}

app sync(external o) {etc}

sync=doall()
summarize(sync);

Any way to make the completion of doall() dependent on the completion of 
all the someapp() calls?

- Mike


On 7/8/08 1:59 AM, Ben Clifford wrote:
> On Tue, 17 Jun 2008, Ben Clifford wrote:
> 
>>> I can definitely see the benefit of having separate pipelines for 
>>> non-dependent parts within the same script, but perhaps there is a way 
>>> to chain dependent functions that is not dependent on files produced by 
>>> previous functions?
>> I've been playing with some code to do that as someone else requested it.
>>
>> Basically you will be able to have a swiftscript variable that expresses 
>> the dependency, but doesn't have any actual content (such as a file).
>>
>> Hopefully later this week there will be something in SVN.
> 
> Somewhat later than I'd hoped. Swift SVN r2095 has 'extern' types. You can 
> use like this: 
> 
> 
> (external o) a() {
>     app {
>         helperA @strcat(@arg("dir"),"/restart-extern.1.out") "/etc/group" 
> "qux";
>     }
> }
> 
> b(external o) {
>     app {
>         helperB @strcat(@arg("dir"),"/restart-extern.2.out") "/etc/group" 
> "baz";
>     }
> }
> 
> 
> external sync;
> 
> sync=a();
> b(sync);
> 
> This makes a dependency between a and b, but doesn't actually move any 
> data around; its entirely up to you to ensure that when the a procedure 
> finishes your data is in the right place for b to find it.
>